e&hi volume 8 no. 1 2006 issn environment and health ...magazine of the international federation...

Environment andHealth InternationalMagazine of the International Federation of Environmental Health

ISSN 1726-9210E

&H

I V

olu

me 8

N

o.

1

2006

INTERNATIONAL FEDERATION OFENVIRONMENTAL HEALTH

President – Jerry Chaka, South Africa

President, Jerry Chaka, South Africa

President Elect, Colm Smyth, Ireland

Hon. Secretary, Mike Halls, Scotland

Hon. Editor, John Stirling, Scotland

Webmasters, Henning Hansen and Jan Joergensen, Denmark

Cover Photographs:Upper: Lake Wakatipu, New ZealandLower: EHPs from the UK visiting Uganda in May2005 meet Student EHOs at Makerere Universityand pose for a camera call after a very successfuldiscussion.

The views expressed in this magazine are notnecessarily the views of the InternationalFederation of Environmental Health

IFEH REGISTERED OFFICEChadwick Court15 Hatfields, London, UK SE1 8DJ

www.ifeh.org

CONTENTS

President’s Comments 3

Levels of inorganics and organics in soil:When is high, high? 4

An assessment of Air Quality in an Enclosed Multi-Storey Car Park 13

Asbestos – Future Risks 16

Groundwater Quality and Health Risks in Onne Community near a Fetiliser Complex in Southern Nigeria 19

Assessment and Monitoring of Chemical Water Quality Parameters in the Mbabane River, Swaziland 24

NEHA Offers Avian-Flu-Pandemic OnlineCourse IBC

Many thanks to all contributors to thisissue of Environment and Health

InternationalDeadline for submission of articles for the

next issue is 1st September 2006

The Hon. Editor, John Stirling, can becontacted at

11 Muirwood DriveCurrie

Edinburgh EH14 5EZSCOTLAND

e-mail: [email protected]

PRESIDENT’S COMMENTSJerry Chaka

It is almost the end of my term of office. It istherefore important to reflect on how theIFEH performed during my term as well as toreflect on the challenges ahead of us.

Meetings of the Board of Directors and of theCouncil were held as scheduled. The RegionGroups also held meetings, with the EuropeGroup (now EFEH) and the Africa Groupmeeting more regularly during the past twoyears whereas the Americas and the Asia &Pacific Groups managed to meet only once.

A regulation on the use of the DevelopmentFund (Regulation 6/2004) was developed andadopted by the Council and a protocol on therole of Associate Members was finalised.Guidelines regarding twinning activitiesamongst IFEH members are being developedand in an effort to see if more exchanges ofpractitioners between countries could beattained, member organizations have beenasked to submit names of contact persons whowill co-ordinate these activities on behalf oftheir organizations in their countries.

IFEH reacted to the Tsunami Disaster inSouth Asia by issuing a press release on thedisaster and donating one thousand poundsSterling to the International Federation of RedCross & Red Crescent Societies, being acontribution towards the disaster relief fund.

A new membership certificate was agreedupon and in due course all members of theIFEH will be issued with one. A policy on theuse of sustainability indicators (Policy Paperno. 8) was developed and adopted by Council.A formal agreement through a memorandumof understanding was also signed betweenIFEH and the International Institute forSustainable Development (IISD). It is hopedthat this will ensure cooperation between thetwo organizations and that the IFEHsustainability indicators project is included inthe IISD compendium of initiatives.

An overall strategy for the IFEH was firsttabled for discussions at the VancouverCouncil meeting. A workshop session isscheduled for the first day of the two-dayCouncil meeting to be held on 17 & 18 June2006 in Dublin, with the aim of trying tofinalise the strategy during the workshop.

I wish to thank all officers and memberorganizations that contributed to the work ofthe IFEH during my term. All that wasachieved was through team efforts. We stillhave challenges ahead of us but these are notinsurmountable. The most pertinent issueswere raised by several member organizationsduring the Vancouver meeting. Otherchallenges relate to the Regional Groups notfunctioning well and therefore failing to givedirection to Council on IFEH matters;attendances at Council meetings by memberorganizations remains a problem and this iscompounded by the failure of someorganisations to respond to matters referred tothem. It is necessary that there is feedback toCouncil from its members and that robustdebates take place at Council meetings. Weare still operating without an office and staff.And recruitment of new members is nothappening; thus we remain with more or lessthe same number of members as we had twoyears ago. It is vitally important that weconsider these challenges and take appropriatesteps to address them.

To the incoming President, Colm Smyth,President-Elect, Benard Forteath and the newHonorary Secretary, whoever that be, I wishyou all the best during your term of office andhope to see you all at Dublin, Ireland in June.

ENVIRONMENT AND HEALTH INTERNATIONAL

3

Levels of inorganics and organics insoil: When is high, high?P Papapreponis,* R Robertson,**M Roworth,*** SA Ogston*, FLR Williams*

* Section of Public HealthDivision of Community Health SciencesUniversity of Dundee, Kirsty Semple Way Dundee DD2 4BF, Scotland

** Address where work was carried out:Department of Environmental and Consumer Protection Dundee City Council Dundee DD1 3RE, ScotlandCurrent address:Health Protection ScotlandClifton House, Clifton PlaceGlasgow G3 7LN, Scotland

*** Department of Public Health Fife NHS Board Cameron House, Cameron BridgeLeven, Fife KY8 5RG, Scotland

Correspondence should be sent to Dr FLRWilliams, [email protected] of Public Health, Division of Community Health SciencesUniversity of Dundee, Kirsty Semple Way Dundee DD2 4BF, Scotland.Tel +44 (0)1382 420117 fax +44(0) 1382 420101

Key words: environmental criteria, soil pollutionguidelines, health

Abstract

BackgroundRapid responses to assessing problems ofcontamination in the environment requireassessors to have a thorough and up to dateknowledge of what constitutes a level ofcontamination that poses a threat to health.Current guidelines and recommendations forlevels of inorganics and organics in soil, air andwater are published in a multitude of disparatejournals, policy documents, governmental andstatutory publications.

ObjectiveThe purpose of this paper was to summarize thecurrent UK, European, or global regulations andguidelines that apply to levels of severalchemicals in soil and to discuss the interpretation

of these guidelines when investigating potentialthreats to health.

ResultsWe report the current guidelines for seventeenchemicals in soil (fourteen inorganic and threegroups of organic substances). There aredifferences between countries in the levels set.There are occasions where the acceptable levels insoil in residential land are set lower than the levelsoccurring naturally as background. Much of theadvice on which levels are set is derived fromanimal studies that typically expose animals to alarge, single dose of a single chemical.

Comment Recommendations for levels of chemicals in soilthat rely on animal exposures to large, singledoses of a chemical do not replicate accurately the‘cocktail’ of chemicals to which we are exposed toin every day life. There is some evidence from airpollution studies that exposure recommendationsshould be lower than current. Furthermore, thevariations that exist in the guidelines for pollutantsin soil are a potential cause of confusion to bothassessors of the environment and also to thepublic and scientists trying to interpret thefindings.

IntroductionQuantifying the level of pollution on theresidential environment is relativelystraightforward. The source of exposure needs tobe correctly identified, and then samples (asappropriate) of air, water, soil and vegetationshould be taken and analysed for the putativepollutant(s). A problem arises however in theinterpretation of results. And with human healthas a primary outcome, the crucial question is, howhigh is high? Nationally agreed standards are themost obvious choice for establishing a criterion.

At present, however, the guidelines areincomplete. Invariably guidelines are based ontoxicological evidence and on risk assessmentstudies. Typically, toxicological evidence isderived from animal experiments during which thetest animal is exposed to one particular chemical.To keep costs to a minimum, the dose of chemicaladministered is usually hundreds of thousands oftimes higher than those normally encountered byhumans during residential exposure1. Riskassessments aim to conceptualise the routes andthe burden of human exposure under specific


4

conditions. The establishment of standard valuesfor acceptable pollution levels is based on thecombination of both approaches.2

Current animal models do not test the impact ofchronic, low doses of exposure; they typicallyassess exposure to single, often massive, doses.There are two major problems with this. First, inreality individuals are exposed to a ‘cocktail’ ofdifferent chemicals and very little is known aboutthe health impact of these ‘cocktails’. Chemicalsmay act together synergistically; their effects maybe additive or multiplicative; or speciation mayoccur. Second, standards that are based on singlemassive doses of a pollutant may have to beappreciably reduced when applied to chronic low-level doses. This is particularly important whensetting standards for the chemicals whichbioaccumulate, such as dioxins, furans and manyof the other organics. Recent studies of the healthoutcome of exposure to chronic, low levels ofairborne pollutants show that levels of exposure toparticulates, nitrogen oxide, sulphur dioxide andcarbon monoxide which were previously thought tobe safe are in fact associated with a higherincidence of asthma3 and with an increase inmortality from various diseases in those exposed.4-7

In determining the health impact of exposure topollutants the choice of disease outcome is guidedgenerally by animal studies and by studies inoccupational epidemiology. However, thedrawback of this approach is that it can ignore theimpact of simultaneous exposures to differentchemicals. The animal studies do not mirror reallife exposures and it is very likely that in someinstances we do not have sufficient knowledge toidentify correctly the health outcomes to monitor.Guideline levels for pollutants are derived fromlimited physical criteria that are generated byanimal studies; other adverse outcomes, such aspsychological illness, may also exist but are moredifficult to elucidate. Adverse psychologicaloutcomes are complex and may result, or beexacerbated by, poor public relations, mediacoverage and political views irrespective of actuallevels of pollutants or any potential for, orevidence of, physical health problems. Forexample, studies of residents near a chemicalwaste dump in Love Canal, USA, found little firmevidence of exposure and ill-health. But due topoor handling of the event, the residents felt mis-informed and frightened to such an extent thatstudies found that the residents were sufferingfrom a range of very real psychological illnesses.8

The composition of effluent coming fromchimneys of modern industry includes a widerange of inorganic and organic substances forinstance: aluminium, antimony, arsenic, beryllium,bismuth, cadmium, chromium, cobalt, copper, iron,lead, magnesium, mercury, molybdenum, nickel,selenium, silver, thallium, tin, titanium, tungsten,uranium, vanadium, zinc and zirconium, sulphurdioxide, nitrogen oxides, polycyclic aromatichydrocarbons, and polychlorinated aromatics.9-13

The challenge facing environmental and publichealth is to accurately describe the health impact ofexposure to low levels of these pollutants.

Routine monitoring of the residential environmentaround industry is a crucial step in evaluating theimpact of that industry upon its neighbourhood.The interpretation and dissemination of the levelsof organics, inorganics and particulate matterfound in the environment need to becommunicated regularly and openly to therelevant communities. Currently the levels ofinorganics and organics in soil, air and water arereported in a multitude of disparate journals,reports, web sites and books. In this paper wehave collated the information from these disparatesources and have created a table that summarizesthe recommended levels of selected chemicals insoil.

MethodsIn 1998 we carried out an extensive literaturesearch that created profiles of 25 of the commoninorganic and organic chemicals that are typicallyfound in chimney effluent.14 Each profiledescribed the regulations and guidelines thatexisted for levels of the chemical in soil, air andwater; the human health consequences of exposureto the chemical; the experimental evidence thatsupported the human health consequences; typicalbackground levels monitored in the environment;and, the major industrial sources that contributedto the environmental burden. For this paper weupdated the regulations and guidelines that applyto levels of inorganics and organics in soil.

The procedures that we used in assessing theliterature were based on guidelines that weredeveloped for undertaking systematic reviews ofresearch and effectiveness.15 Briefly, we reviewedall papers reported in English that were publishedin the 1990’s, but we also reviewed key papersfrom earlier decades. Data sources includedMedline, professional organizations, statutoryorganizations and the web.


5

ResultsRecommended soil levels for 17 inorganic andorganic chemicals were found in the literature(table 1). Some guidelines could not be found, forexample the UK limits for antimony in soil; andsome guidelines were somewhat old, for examplecopper (table 1). For those guidelines that are upto date and comprehensive it is clear that, betweencountries, there are wide variations in what isdeemed acceptable. For instance the UK allows

soil lead in residential land to reach 450 mg/kg,whereas Canada sets 140 mg/kg as the maximumlimit (table 1). There are also examples of themaximum soil values for residential land being setbelow levels that occur naturally as background.For example the UK guideline for arsenic in soil is20 mg/kg yet in the south-west of England itoccurs naturally at levels between 29-51 mg/kg(table 1).


6

Table 1 Recommended levels for selected inorganic and organic chemicals in soilNB mg/kg is the same as µg/g and ppm

Acceptable levels for residential landSubstance UK limit Other (country) limit Background

Antimony 20 mg/kg (Canada)0 0.19-1.77 µg/g (World wide)17

20 mg/kg (Netherlands) 0 3 mg/kg (mean Netherlands) 0

100 mg/kg (France) 0 1-8.8 ppm (mean=0.48 ppm) (USA) 0

20mg/kg (Denmark) 0

Arsenic (inorganic) 20 mg/kg 0 12 mg/kg (Canada) 0 29-51 mg/kg (south-west England) 0

50 mg/kg (Germany)0 29 mg/kg (mean Netherlands) 0

55 mg/kg (Netherlands) 0 10 mg/kg (90th percentile Sweden)* 0

37 mg/kg (France) 0 1-50 mg/kg (Australia) 0

15 mg/kg (Sweden) 0 0.1-97 µg/g (mean=7.2) (USA) 0

100 mg/kg (Australia) 0

30 mg/kg (New Zealand) 0

Beryllium 4 mg/kg (Canada) 0 0-5 ppm (UK)20

500 mg/kg (France) 0 1.1 mg/kg (mean Netherlands) 0

20 mg/kg (Australia) 0 1.2-12.1 ppm (USA)17

1-15 mg/kg (mean=0.63) (USA) 0

Cadmium 1-8 mg/kg 0 10 mg/kg (Canada) 0 <0.2-5.9 (England) 0

20 mg/kg (Germany) 0 0.8 mg/kg (mean Netherlands) 0

12 mg/kg (Netherlands) 0 0.3 mg/kg (90th percentile Sweden)* 0

20 mg/kg (France) 0 1 mg/kg (Australia) 0

0.5 mg/kg (Denmark) 0 100 to 1000 µg/kg (USA)21

0.4 mg/kg (Sweden) 0 0.25 ppm (mean USA) 0


Chromium (total) 130 mg/kg 0 64 mg/kg (Canada) 0 0.2-838 mg/kg (UK)22

400 mg/kg (Germany) 0 22-1297 (British Geological Survey)22


130 mg/kg (France) 0 30 mg/kg (90th percentile Sweden)* 0

500 mg/kg (Denmark) 0 5-1000 mg/kg (Australia) 0

120 mg/kg (Sweden) 0 1-2000 mg/kg (geom.mean = 37) (USA) 0

Cobalt 50 mg/kg (Canada) 0 1.6-21.5 µg/g (World wide) 17

240 mg/kg (Netherlands) 0 10 µg/g (Canada) 23

240 mg/kg (France) 0 9 mg/kg (mean Netherlands) 0

30 mg/kg (Sweden) 0 10 mg/kg (90th percentile Sweden)* 0

100 mg/kg (Australia) 0 1-40 mg/kg (Australia) 0

7.2 mg/kg (mean USA) 0


7

Copper 130 mg/kg 24 63 mg/kg (Canada) 0 6-8 µg/g (World wide) 17

190 mg/kg (Netherlands) 0 0-100 ppm (UK) 20

190 mg/kg (France) 0 30 µg/g (Canada) 23

500 mg/kg (Denmark) 0 36 mg/kg (mean Netherlands) 0



14-41 mg/kg (USA) 0

Dioxins & Furans 4 ng TEQ/kg (Canada) 0 1-64 ng TEQ/kg (Austria) 0

1000 ng TEQ/kg (Germany) 0 2.1-8.9 ng TEQ/kg (Belgium) 0

1000 ng TEQ/kg (Netherlands) 0 1-30 ng TEQ/kg (Germany) 0

1000 ng TEQ/kg (France) 0 2-45 ng TEQ/kg (Greece) 0

2 ng TEQ/kg (Finland) 0 1-13 ng TEQ/kg (Ireland) 0

1500 ng TEQ/kg (New Zealand 0 1-43 ng TEQ/kg (Italy) 0

1000 ng TEQ/kg (Japan) 0 1.4-20 ng TEQ/kg (Luxemburg) 0

1000 ng TEQ/kg (USA) 0 2.2-16 ng TEQ/kg (Netherlands) 0

1-24.2 ng TEQ/kg (Spain) 0

< 1 ng TEQ/kg (Sweden) 0

1-87 ng TEQ/kg (UK) 0

6.5 pg/g (mean Japan) 0

Lead 450 mg/kg 25 140 mg/kg (Canada) 0 10-84 µg/g (World wide) 17

400 mg/kg (Germany) 0 23 mg/kg (UK) 25

530 mg/kg (Netherlands) 0 3-16,338 mg/kg (median=40) (UK) 25

400 mg/kg (France) 0 25 µg/g (Canada) 23


80 mg/kg (Sweden) 0 25 (mg/kg) (90th percentile Sweden)* 0


Manganese 0-500 ppm 20 1500 mg/kg (Australia) 0 80-1300 µg/g (World wide) 17


Mercury 8 mg/kg 26 6.6 mg/kg (Canada) 0 0.02-0.41 ppm (World wide) 17

20 mg/kg (Germany) 0 10-1800 µg/g (UK) 26

10 mg/kg (Netherlands) 0 0.3 mg/kg (mean Netherlands) 0

7 mg/kg (France) 0 0.1 mg/kg (90th percentile Sweden)* 0

1 mg/kg (Denmark) 0 0.03 mg/kg (Australia) 0

1 mg/kg (Sweden) 0


Nickel 50 mg/kg 28 50 mg/kg (Canada) 0 4-55 µg/g (World wide)17

140 mg/kg (Germany) 0 40-80 mg/kg (England)28

210 mg/kg (Netherlands) 0 27 (mean Scotland) mg/kg28

140 mg/kg (France) 0 20 (mean England) mg/kg 28


35 mg/kg (Sweden) 0 20-25 mg/kg (90th percentile Sweden)* 0


<5-700 ppm (geom.mean=13 ppm) (USA) 0

PAHs 50 mg/kg 24 21.3 mg/kg (Canada) 0 1 mg/kg (mean Netherlands) 0

40 mg/kg (Netherlands) 0 5 mg/kg (90th percentile Sweden) 0

20.3 mg/kg (Sweden) 0



8

PCBs 1 mg/kg 24 1.3 mg/kg (Canada) 0

1.0 mg/kg (Netherlands) 0

0.02 mg/kg (Sweden) 010 mg/kg (Australia) 0

Selenium 35 mg/kg 29 1 mg/kg (Canada) 0 0.05-0.09 mg/kg (Worldwide) 0

0.02 to 2 mg/kg (England & Wales) 29

0.7 mg/kg (mean Netherlands) 0

0.01-0.2 mg/kg (USA) 0

Vanadium 0-100 ppm 20 130 mg/kg (Canada) 0 5-190 µg/g (World wide)17

560 mg/kg (France) 0 42 mg/kg (mean Netherlands) 0


20-50 mg/kg (Australia) 0

200 mg/kg (mean USA) 0

Zinc 130 mg/kg 24 200 mg/kg (Canada) 0 60 µg/g (Canada)23


9000 mg/kg (France) 0 60-70 mg/kg (90th percentile Sweden)* 0

500 mg/kg (Denmark) 0 10-300 mg/kg (Australia) 0

350 mg/kg (Sweden) 0 <5-2900 mg/kg (mean=60 mg/kg) (USA) 0


* For the Swedish background levels, figures represent the 90th percentile value of the samples analysed

Discussion There is concern that the guidelines for maximumlevels of chemicals in soil, air and water areinadequate. This is exemplified by thecontroversy surrounding acceptable levels ofdioxins and furans in soil. The Canadianguidelines16 set 4 ngTEQ/kg (ng toxic equivalentper kg of soil) as the maximum permissible forresidential parkland, for agricultural soils and forindustrial land; whereas Germany sets 1000ngTEQ/kg for residential land and for parks andrecreational areas, 10,000 ngTEQ/kg for industrialareas, and 100 ngTEQ/kg for playgrounds.19 Ahuge range of concentrations of dioxins and furansin the soil in the UK has been reported as typicalof background concentrations. Scottish Power30

report in a Department of the Environmentreport31 that a reasonable estimate for backgroundTTEQ (total toxic equivalents) levels in theEngland, Wales and Lowland Scotland is 2.49ng/kg. This contrasts to reported concentrationson industrial and urban land32 of 24 ng/kg, of 54ng/kg33 and various concentrations taken fromurban sites ranging from 65 ng/kg for TCCD to232 ng/kg for TCDF34 and for rural sites of 10.3ng/kg.33 Interpretation of what is and what is nota high level of soil contamination is almostimpossible using these guidelines.

The main purpose of adhering to guidelinerecommendations is the belief that therecommended maximum concentration specifiedby the guideline for any particular contaminantwill not pose an unacceptable risk to health.Guideline recommendations are media-specific;that is, they are set independently for soil, forwater and for air. From a public healthperspective this is unsatisfactory because differentchemicals contaminate human beings throughdifferent routes of exposure. For example it hasbeen estimated, assuming a soil ingestion rate of0.02 g per day, that exposure to TCDD might beapportioned as follows: 1.1% from air, 98.8%from food, 0.05% from soil and 0.01% fromwater.35 Since direct ingestion of contaminatedsoil and water are not important routes for humanexposure to TCDD, could higher guideline valuesfor soil and water contamination be allowed forthis chemical under certain circumstances?Naturally, this would change if householders oncontaminated land consumed large quantities ofhome-grown vegetables, or home-reared livestock.

Establishing the maximum acceptable levels ofthese substances in soil (or air) is notstraightforward. Regulations and guidelines insoil and the air do not exist for all of these

substances. The interpretation of standards andregulations for soil is complicated by the use ofdifferent units of measurement and the duration ofsampling period. The units used for soil levelsmay be mg/kg of air dried soil, µg/g of soil,g/ha/yr or parts per million (ppm). The durationsof the sampling period used for determining levelsin soil may be one-off (spot) measurements, amean value derived from daily, weekly, monthlyor annual measurements, or in many cases simplyspecified as long term, or short term.Measurements made intermittently do notnecessarily adequately represent the exposure ofthe population. An additional problem wheninterpreting the standards and regulations for soillies in the typical daily use of the soil. Many ofthe standards and regulations are set assuming thesoil is to be used for growing plants and crops.However, susceptible people such as childrenplaying in gardens, gardeners and builders canconsume appreciable quantities of soil throughdirect contact of the soil coupled with inadequatecleaning of the their hands.

Standards and regulations are not absolute, asshown by the large range seen between and evenwithin countries. For instance, the guideline forthe soil concentration of arsenic in residential landin the UK is 20 mg/kg2 whereas in Canada it is 12mg/kg.16 This contains some degree ofuncertainty because of the lack of humantoxicological data on which to base the standard.Different chemicals target different organs of thebody;36 toxicity can vary between species – forexample had penicillin been tested on miceinstead of guinea pigs it would never have beenpassed for human trials because the guinea pig isexceptionally sensitive to penicillin and itsingestion kills 50% of the sample.37 Toxicity alsovaries between the sexes;38 and the old, theimmunocompromised and the young are generallymost susceptible to the effects of toxicants.39

Human data are preferred for the formation ofstandards but standards are often based only onanimal studies because the relevant human studiesare lacking. Even when human data are availableinterpretation is hampered as some investigatechronic exposure whilst other investigate acuteexposure. The interpretation and application ofstandards is a balance between legal requirementson the one hand and local factors and conditionson the other.

Another important issue is the exposure pathwayand the exposure conditions under which an

individual or a community come into contact withpollutants. Human exposure to toxicants mayoccur under several conditions depending on theenvironmental setting. Differences associatedwith occupational or residential environment;distance from the source of pollution;meteorological conditions; land use; consumptionof locally-grown crops and local-breed livestockshould be taken into account when interpretingresults of environmental measurements. All theseparameters, in association with thephysicochemical properties of pollutants, lead to adifferent intake of pollutants by individuals.Guidelines attempt to reflect some of thisvariation and, for example, the Department forEnvironment, Food and Rural Affairs (DEFRA) ofthe UK Environment Agency provides guidelinesfor the upper acceptable concentrations of severalpollutants in soil that are dependent upon the soiluse. For instance the guidelines for mercuryrange from 8 mg/kg in residential land (with orwithout plant uptake) to 480 mg/kg for land usedfor commercial or industrial purposes.26

A key goal for environmental epidemiology is theestablishment of cause and effect between a(putative) pollution source and ill health. A majorproblem for achieving this is that chemicals areoften produced by a variety of sources. Forinstance, although all of the chemicals describedin table 1 are produced by municipal wasteincineration, they are also produced by a varietyof other sources. All of the chemicals are found intobacco smoke, 10 of the 17 are liberated throughburning coal, and 6 of the 17 are found in exhaustemissions from motor vehicles. Municipal wasteincineration is the major contributor of 9 of the 17chemicals. In addition all of these chemicalsoccur at background levels in the environment.Confirmation of an unequivocal associationbetween an industrial source and an adverseenvironmental or human health impact maytherefore be extremely difficult.

DEFRA report series on Soil Guideline Valuese.g. 2,18 suggest that any guidelines should beused by a risk assessor as “a component of anoverall risk assessment and management strategy”,which implies that they constitute an indicativetool for risk assessment and not an absolute rule.The report points out that “the assessor shouldtake into account site-specific circumstances” andthat “a potentially significant risk might be presenteven though a soil guideline value is notexceeded.”


9


10

This ‘open to interpretation’ advice highlights theproblems associated with implementing such adiversity of limits, recommended values andguidelines in the operational field. The differentapproaches may be exacerbated by the wide rangeof professionals who are left to try to interpretthese values and to ensure compliance withstatute. If the evidential base for such work is tobe developed then the need for comprehensive androbust environmental studies is a prerequisite.Inherent in this aim is an assumption that theworkforce carrying out the work is adequatelyresourced both in terms of personnel and budgetsfor the carrying out of investigative fieldwork.This resource is often not available and theresultant inconsistencies in duration, type andtotality of sampling undoubtedly impedes theformation of an evidential base. Public bodieswhen faced with a potential public health incidentsurrounding for example a point pollution sourcemay find resourcing of investigative workprohibitive and therefore opportunities tostrengthen the evidential base maybe lost.

The current reliance by practitioners onenvironmental guidelines may be alleviated in partby the continued development and implementationof concepts such as the ‘precautionary principle’.One commonly accepted definition of theprecautionary principle is: ‘The precautionaryprinciple provides a framework, procedures andpolicy tools for public policy actions in situationsof scientific complexity, uncertainty andignorance, where there may be a need to act inorder to avoid, or reduce, potentially serious orirreversible threats to health or the environment,using an appropriate level of scientific evidence,and taking into account the likely pros and cons ofaction and inaction.40 The adoption of such aprinciple would it is hoped assist themultidisciplinary public health workforceovercome the inherent difficulties in the use ofenvironmental limits to protect human health byhelping to ‘foresee and forestall hazards’.41 Theimpact of such a process would be greatlyenhanced if effective and comprehensive riskcommunication, education and awareness raisingtakes place with the affected local communitiesthroughout the investigative process. Such activeinclusion of the local population is essential if allhealth impacts including the psychosocial impactsof a particular site or project are to be trulyaddressed.

At the present time environmental limits forchemicals vary in terms of both their derivationand their application. Despite theseinconsistencies there is still reliance bypractitioners on using these values in theoperational setting when trying to protect humanhealth. This reliance may lead to an inaccuratepicture of the true human health impact of aparticular community based environmentalexposure. The need for the development of asound evidential base for such guidelines throughadequate resourcing at both a research andoperational level requires to be addressed as amatter of urgency. The further development ofdiffering methods of dealing with environmentalrisks to human health such as the precautionaryprinciple and risk communication are to bewelcomed if this helps to reduce the currentreliance on environmental guidelines.

PP undertook some of this work while in receipt ofa State Scholarship Foundation of Greece. Thework was part funded by the Dundee City Council.

Main messages and policy implicationsCurrent guidelines and recommendations forlevels of inorganics and organics in soil, water andair are published in a multitude of disparatejournals, policy documents, governmental andstatutory publications.

There is variation in guidelines andrecommendations for levels of inorganics andorganics in soil, water and air both within andbetween countries.

Guidelines and recommendations for levels ofinorganics and organics in soil, water and air donot necessarily reflect accurately the hazardrepresented by chronic exposure to low levels of a‘cocktail’ of chemicals.

The precautionary principle – which provides aframework, procedures and policy tools for publicpolicy outcomes – may provide an alternativeapproach to evaluating the health impact insituations of putative contamination.


11

ReferencesBMA. Health and environmental impact assessment. Anintegrated approach. London: Earthscan publications. 1998.DEFRA. SGV soil guidelines values for arseniccontamination. DEFRA Report Series. Bristol March 2002.http://www.environment-agency.gov.uk/commondata/acrobat/sgv1_arsenic_676042.pdfaccessed February 2006Ponka A. Asthma and low level air pollution in Helsinki.Archives of Environmental Health. 1991:46:262-267.Schwartz J, Spix C, Touloumi G, Bacharova L,Barumamdzadeh T, le Tertre A, Piekarski T, Ponce de LeonA, Ponka A, Rossi G, Saez M, Schouten JP. Methodologicalissues in studies of air pollution and daily counts of deaths orhospital admissions. Journal of Epidemiology andCommunity Health. 1996;50(Suppl 1):S3-S11.Schwartz J. Air pollution and daily mortality: a review andmeta-analysis. Environmental Research. 1994;64:36-52.Schwartz J, Slater D, Larson TV, Pierson WE, Koenig JQ.Particulate air pollution and hospital emergency room visitsfor asthma in Seattle. American Reviews RespiratoryDisease. 1993;147:826-831.Dockery DW, Pope CA, Xu X, Spengler JD, Ware JH, FayME, Ferris BG, Speizer FE. An association between airpollution and mortality in six US Cities. The New EnglandJournal of Medicine. 1993;329:1753-1759.Holden C. Love Canal residents under stress. Science.1980;208:1242-1244.Suter-Hofmann M, Schlatter C. Toxicity of particulateemissions from a municipal incinerator: critique of theconcept of TCDD-equivalents. Chemosphere 1986; 15:1733-1743.Environemtnal Agency. Processes subject to integratedpollution control. IPC Guidance Note. London HMSO.1996.Houghton SJ. Royal Commission on environmentalpollution: incineration of waste. 17th Report. LondonHMSO. 1993.Eduljee GH. Organic micropollutant emissions from wasteincineration. Issues in Environmental Science andTechnology. 1994.Kelly KE. Health risk assessment of hazardous wasteincinerator stack emissions. Hazardous Waste and HazardousMaterials. 1986;3:367-403.Williams FLR, Robertson R, Roworth M. Detailed profilesof 25 major organic and inorganic substances. Glasgow:Scottish Centre for Infection and Environmental Health.1999.CRD. NHS Centre for reviews and dissemination.Undertaking systematic reviews of research on effectiveness.CRD guidelines for those carrying out or commissioningreviews. University of York. 1996.Canadian Council of Ministers of the Environment. Canadiansoil quality guidelines for the protection of environmental andhuman health: update 2003. Winnipeg: CCME, 2003.McBride MB. Trace and toxic elements in soils.Environmental Chemistry of soils. Oxford: OxfordUniversity Press. 1994:308-341.DEFRA. SGV soil guidelines values for cadmiumcontamination. DEFRA Report Series. Bristol March 2002.http://www.environment-agency.gov.uk/commondata/acrobat/sgv3_cadmium_676065.pdfaccessed February 2006

German Federal Ministry for the Environment, NatureConservation and Nuclear Safety. Federal soil protection andcontaminated sites ordinance Annex 2. Bonn 1999.Society of the Chemistry Industry. Site investigation andmaterials problems. Proceedings: conference on reclamationof contaminated land. Eastbourne 1979.Barltrop D, Strehlow CD. Clinical and biochemical indicesof cadmium exposure in the population of Shipman.Proceedings 3rd International Cadmium Conference. 1981.DEFRA. SGV soil guidelines values for chromiumcontamination. DEFRA Report Series. Bristol March 2002.http://www.environment-agency.gov.uk/commondata/acrobat/sgv4_chromium_676070.pdfaccessed February 2006Canadian Council of Ministers of the Environment. InterimCanadian environmental quality criteria for contaminatedsites. Winnipeg: CCME, 1991.ICRCL. Guidance on the assessment and redevelopment ofcontaminated land. London: Inter – departmental committeeon the redevelopment of contaminated land 59/83, 1983.DEFRA. SGV soil guidelines values for lead contamination.DEFRA Report Series. Bristol March 2002.http://www.environment-agency.gov.uk/commondata/acrobat/sgv10_lead_676098.pdfaccessed February 2006DEFRA. SGV soil guidelines values for inorganic mercurycontamination. DEFRA Report Series. Bristol March 2002.http://www.environment-agency.gov.uk/commondata/acrobat/sgv5_inorg_mercury_676075.pdfaccessed February 2006Circular on target values and intervention values for soilremediation. Ministerie van Volkshuising, RuimtelijkeOrdening en Milieeubeheer (The Dutch EnvironmentMinistry). The Hague. 4th February 2000.http://www2.minvrom.nl/Docs/internationaal/annexS_I2000.pdf accessed February 2006.DEFRA. SGV soil guidelines values for inorganic nickelcontamination. DEFRA Report Series. Bristol March 2002.http://www.environment-agency.gov.uk/commondata/acrobat/sgv7_nickel_676082.pdfaccessed February 2006DEFRA. SGV soil guidelines values for inorganic seleniumcontamination. DEFRA Report Series. Bristol March 2002.http://www.environment-agency.gov.uk/commondata/acrobat/sgv9_selenium_676091.pdfaccessed February 2006Scottish Power. Ambient air and soil analysis. 1st survey.Dundee: Dundee Energy Recycling Limited. 1999: 1-10.Department of the Environment. Dioxins in the environment,Pollution Paper No 27. Central Directorate of EnvironmentalProtection. London HMSO 1989.Fernandes AR, Timmis R, Dawes C. A survey of dioxincontents of solid waste in Walsall, UK. Stevenage: WarrenSprings Laboratory, 1993.ENDS. High dioxin levels in soil and cattle around a Coaliteplant. ENDS Report 1992:206:6.Creaser CS, Fernandes AR, AL-Haddad A, Harrad SJ, HomerRB, Skett PW, Cox EA. Survey of background levels ofPCDD and PCDF’s in urban British soils. Chemosphere1990;21:931-938.Travis CC, Hattemer-Frey HA. Human exposure to dioxin.The Science of the Total Environment. 1991;104:97-127.


12

Goyer RA. Toxic effects of metals. In: Klaassen CD, AmdurMO, Doull J (Edits). Casarett and Doull’s Toxicology: Thebasic science of poisons. 3rd ed. New york: MacmillanPublishers. 1986:582-635.Wilson D. Penicillin in perspective. London Faber andFaber. 1976.Pesatori AC, Consonni D, Bachetti S, Zocchetti C, BonziniM, Baccarelli A, Bertazzi PA. Short and long term morbidityand mortality in the population exposed to dioxin after theSeveso accident’. Industrial Health 2003:41:127-138.McConnell E. Acute and chronic toxicity, carcinogenesis,reproduction, teratogenesis and mutagenesis in animals.Topics in environmental Health. 1980;4:109-150.Harremo P, Gee D, MacGarvin M, Stirling A, Keys J, WynneB, Guedes Vaz S (Edits). Late lessons from early warnings:the precautionary principle 1896-2000. Environmental issuereport No 22, European Environment Agency: Luxembourg:Office for Official Publications of the EuropeanCommunities. 2002http://reports.eea.eu.int/environmental_issue_report_2001_22/en/tab_abstract_RLR accessed February 2006SNIFFER. Application of the precautionary principle. Reportof workshop held at the Corus Hotel Edinburgh North, NorthQueensferry. 18th and 19th of May, 2004.Darmendrail D. The French approach to contaminated landmanagement. 2001.http://www.sanaterre.com/guidelines/french.htmaccessed February 2006Sanaterre Environmental. Soil Plan Zealand. July 2001.http://www.sanaterre.com/guidelines/zealand.htmaccessed February 2006Swedish Environment Protection Agency. SwedishEnvironment Quality Criteria for Contaminated Sites:Assessment of Contamination Level. 30 September 2002.http://www.internat.environ.se/index.php3?main=/documents/legal/assess/assedoc/cont.htm accessed February 2006Australian National Environment Protection Council.Guidelines on the Investigation Levels for Soil andGroundwater. 1999.http://www.ephc.gov.au/pdf/cs/cs_01_inv_levels.pdfaccessed February 2006New Zealand Ministry of the Environment. Health andEnvironmental Guidelines for selected Timber TreatmentChemicals: Chapter 5 Soil Acceptance Criteria. Wellington,June 1997.http://www.mfe.govt.nz/publications/hazardous/timber-guide-jun97/chapter-5-jun97.pdf accessed February 2006Petersen A. Compilation of EU Dioxin Exposure and HealthData: Task 1 – Review of Member State Legislation andProgrammes. AEA Technology plc: Abingdon, Oxfordshire,October 1999.http://europa.eu.int/comm/environment/dioxin/download.htm#CompilationofEUDioxinexposureandhealthdataaccessed February 2006Japanese Ministry of the Environment. InformationalBrochure – Dioxins. Tokyo 2003.http://www.env.go.jp/en/topic/dioxin/brochure2003.pdfaccessed February 2006Pattle Delamore Partners Ltd. Dioxin Concentrations inResidential Soil, Paritutu, New Plymouth, Appendix D:Summary of NZ and Overseas Soil Guidelines for Dioxin.Wellington, 2002http://www.mfe.govt.nz/publications/hazardous/taranaki-dioxin-report-sep02/appendix-d-sep02.pdfaccessed February 2006

Fiedler H. Compilation of EU Dioxin Exposure and HealthData: Task 2 – Environmental Levels. AEA Technology plc:Abingdon, Oxfordshire, October 1999.http://europa.eu.int/comm/environment/dioxin/download.htm#CompilationofEUDioxinexposureandhealthdataaccessed February 2006Agency for Toxic Substances and Disease Registry.Toxicological Profile for Antimony and Compounds.Atlanta, 1992.http://www.atsdr.cdc.gov/toxprofiles/tp23.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry. DraftToxicological Profile for Arsenic. Atlanta 2005.http://www.atsdr.cdc.gov/toxprofiles/tp2.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry.Toxicological Profile for Beryllium. Atlanta 2002.http://www.atsdr.cdc.gov/toxprofiles/tp4.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry.Toxicological Profile for Cadmium. Atlanta 1999.http://www.atsdr.cdc.gov/toxprofiles/tp5.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry.Toxicological Profile for Chromium. Atlanta 1999.http://www.atsdr.cdc.gov/toxprofiles/tp7.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry.Toxicological Profile for Cobalt. Atlanta 2004.http://www.atsdr.cdc.gov/toxprofiles/tp33.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry.Toxicological Profile for Copper. Atlanta 2004.http://www.atsdr.cdc.gov/toxprofiles/tp132.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry. DraftToxicological Profile for Nickel. Atlanta 2003.http://www.atsdr.cdc.gov/toxprofiles/tp15.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry.Toxicological Profile for Selenium. Atlanta 2003.http://www.atsdr.cdc.gov/toxprofiles/tp92.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry.Toxicological Profile for Vanadium and Compounds. Atlanta 1992.http://www.atsdr.cdc.gov/toxprofiles/tp58.htmlaccessed February 2006Agency for Toxic Substances and Disease Registry. DraftToxicological Profile for Zinc. Atlanta 2003.http://www.atsdr.cdc.gov/toxprofiles/tp60.htmlaccessed February 2006

An Assessment of Air Quality in anEnclosed Multi-Storey Car Park

Mark Lyne,School of Population Health, University ofAuckland and Division of Applied Sciences,Auckland University of Technology, New Zealand

Michael Morrice,Division of Applied Sciences, Auckland Universityof Technology, New Zealand

IntroductionThere is very littleresearch that hasbeen done in NewZealand regardingair quality withinenclosed carparking buildings.However researchshows that anestimated 400premature deathsoccur each year inNew Zealand due tomotor vehicleemissions.iIn addition topremature deaths,acute and chronic

health effects including asthma, heart disease andbronchitis, as well as increased hospitalisationsand restricted activity (sick days) are alsoattributable to vehicle emissions.ii

Estimates of the contribution of motor vehicleemissions to air pollution in Auckland are in theorder of 70 to 90% for carbon monoxide andnitrogen oxides.iii

The aim of this study was to;• Measure levels of motor vehicle emissions

within an enclosed multi-storey car park; • Compare results with standard and guideline

values; and• Identify potential health risks and impacts of

motor vehicle emissions.

The car park monitored was the busiest enclosedmulti-storey car park in the Auckland region,based upon the number of cars that visit the sitedaily. It has two levels and provides parking for alarge retail shopping mall and supermarket.

Carbon monoxide, nitrogen oxides and nitrogendioxide levels were monitored at four sites withinthe car park, two on each level. Both instanttesting gas detector tubes and diffusion tubepassive samplers were used to monitor the sitesover a three- month period.

BackgroundThe health effects of motor vehicle emissions andambient air pollution are known but due to thenature of enclosed multi-storey car parks it isanticipated that these health risks may beamplified.iv This is of particular concern since itmay be possible that it will have a cumulativeeffect and also because employees andsubcontractors that provide security, maintenanceand other various services may be subjected towork in these environments for a substantialperiod of time.

Carbon monoxide is the end result of incompletecombustion of fossil fuels, usually by petrol anddiesel engines. It is an odourless, colourless gas,heavier than air, which means that it may collectand accumulate in confined spaces. At risk humanpopulation groups include children, pregnantwomen and their developing foetuses and peoplewith pre-existing respiratory and heartconditions.2

Carbon Monoxide reduces the ability ofhaemoglobin in the bloodstream to carry oxygensuch that the blood is unable to release enoughoxygen into the body’s tissues and other sensitiveorgans such as the brain and heart. It does notdirectly affect the lung tissue except at extremelyhigh concentrations that are unlikely to beexperienced in normal circumstances. Poisoningcan cause short-term neurological deficits that arereversible and severe, often delayed, neurologicaldamage. Low concentration poisoning ischaracterised by headaches, but as concentrationsincrease, symptoms include dizziness, nausea andvomiting.v

The primary source of anthropogenic nitrogenoxides is from the combustion of fossil fuels frommotor vehicles. Nitrogen oxides readily formnitric acid when they come into contact with waterwithin the body; the most effected parts are theeyes, lungs, mucous membranes and skin. Themost susceptible groups are young children,asthmatics, and people with chronic bronchitis andother related conditions.1


13

This article was first published in the New Zealand Journalof Environmental Health

Nitrogen dioxide can significantly contribute tomorbidity and mortality, particularly in theprevious susceptible groups. When exposed torelatively high concentrations of nitrogen dioxidelung irritation and potentially long-term lungdamage may occur.1

MethodFor the purpose of this study the sampling ofcarbon monoxide, nitrogen oxides and nitrogendioxide was carried out. Nitrogen dioxide was

monitored constantly over the three-month periodat each site using diffusion tube passive samplers(average fortnightly levels). Carbon monoxideand nitrogen oxides were both monitored usingGastec gas detector tubes (instant levels). Carbonmonoxide was also monitored using Gastec 8 hourdiffusion tube passive samplers (average 8 hourlevels).

ResultsCarbon Monoxide (instant levels)

Site Highest level Mean Lowest Guideline No. ofreadings taken

No. of exceedencesof Guideline

A 75ppm 50ppm 20ppm 90ppm(15min) 9 0

B 60ppm 38ppm 15ppm 90ppm(15min) 9 0

C 70ppm 37ppm 15ppm 90ppm(15min) 9 0

D 60ppm 39ppm 20ppm 90ppm(15min) 9 0


14

Carbon Monoxide highest instant levels Carbon Monoxide highest 8 hour levels

Site Highest level Mean Lowest Standard No. ofreadings taken

No. of exceedencesof Standard

A 20ppm 17ppm 14ppm 10ppm(8 hour) 5 5

B 17ppm 14ppm 11ppm 10ppm(8 hour) 6 6

C 17ppm 13ppm 9ppm 10ppm(8 hour) 6 4

D 23ppm 16ppm 11ppm 10ppm(8 hour) 5 5

Carbon Monoxide (8 hour levels)

Nitrogen Oxides(instant levels)

Nitrogen Oxides highest levels

Nitrogen Dioxide (fortnightly levels)

DiscussionWhile all the instant carbon monoxide levels fellwithin the guideline value, almost all of the 8 hourcarbon monoxide levels exceeded the standardvalue, although a 15 minute guideline set by theWorld Health Organisation was used for thecomparison of the former due to a lack of anyinstant guideline or standard value. The standardused for 8 hourly carbon monoxide levels is set bythe Ministry for the Environment (New Zealand).

Of the 32 instant readings that were taken fornitrogen oxides, 15 exceeded the guideline value.There are no guideline or standard values set fornitrogen oxides in New Zealand and for this

comparison a guideline set by the Department of the Environmental Affairs and Tourism (SouthAfrica) was used.

12 of the 24 fortnightly nitrogen dioxide levelsexceeded the guideline value. An annual guidelinevalue set by the World Health Organisation wasused for comparison since no similar guideline orstandard values are set in New Zealand for annuallevels.

Since levels of carbon monoxide, nitrogen oxideand nitrogen dioxide monitored within theenclosed multi-storey car park exceeded guidelineand standard levels set to protect human health, it


15



A 1500ppm 1075ppb 400ppb 900ppb(instant) 8 6

B 1000ppm 706ppb 400ppb 900ppb(instant) 8 3

C 1900ppm 700ppb 200ppb 900ppb(instant) 8 2

D 1900ppm 888ppb 400ppb 900ppb(instant) 8 4



A 47.5µg/m3 42.2µg/m3 37.2µg/m3 40µg/m3

(annual) 5 3

B 47.5µg/m3 41.2µg/m3 38.2µg/m3 40µg/m3

(annual)5 3

C 46.8µg/m3 42.0µg/m3 34.8µg/m3 40µg/m3

(annual)5 3

D 47.8µg/m3 42.5µg/m3 36.1µg/m3 40µg/m3

(annual)5 3

Nitrogen Dioxide highest levels


16

suggests that there is the potential for health riskscaused by motor vehicle emissions.

LimitationsDue to practicability, only carbon monoxide,nitrogen oxides and nitrogen dioxide weremonitored. Other pollutants (e.g. particulates, andvolatile organic compounds etc.) which are alsoemitted from vehicles and harmful to health werenot monitored. However, those gases which weremonitored give an indication of the general airquality within the enclosed multi-story car parkand provide the basis for further research andmore detailed monitoring.

It is accepted that the monitoring methods usedare not as accurate and precise as real-timemonitoring. However, taking into considerationcoefficients of variation and standard deviationsfor the monitoring methods used, results stillsuggest the potential for health risks due toelevated levels of those pollutants monitored.

For further information contact Mark Lyne [email protected]

ReferencesFisher, G., et al., Health Effects Due to Motor Vehicle AirPollution in New Zealand, Report to the Ministry ofTransport, January 2002.

Ministry of Transport, The New Zealand Vehicle EmissionsScreening Programme, 2004, 1-28.

Ministry for the Environment, and Ministry of Transport,Ambient Air Quality and Pollution Levels in New Zealand:Targets for Vehicle Emissions Control, Air Quality reportNo.9, December 1998.

Burnett, J., and Chan, M.Y., Criteria for Air Quality inEnclosed Car Parks, Proc. Instn Civ. Engrs, Transp., 1997,123, May, 102-110.

World Health Organisation (WHO), Air Quality Guidelines,Second Edition. WHO Regional Office for Europe,Copenhagen, Denmark, 2000.

ASBESTOS – FUTURE RISKS?

Robin Howie, Robin Howie Associates

Exposure to asbestos can cause, in order ofincreasing severity: pleural plaques, benignpleurisy, diffuse pleural thickening, asbestosis,asbestos-induced lung cancer and mesothelioma.Of the above diseases, the most critical areasbestos-induced lung cancer and mesothelioma,as both are fatal. About 93% of patients with lungcancer die within 5 years of diagnosis and theaverage survival from diagnosis in patients withmesothelioma is about 8 months. Mesothelioma isa cancer of the pleura (the lining of the lungs) theperitoneum (the lining of the gut) or thepericardium (the lining of the heart). About 90%of mesotheliomas occur in the pleura.

There is a “latent period” of generally about 20-30 years between first exposure to asbestos anddevelopment of asbestos-induced lung cancer. Thelung cancer risk with asbestos is synergistic withsmoking: a smoker who is exposed to asbestoshas about a fifteen times greater risk ofdeveloping lung cancer than an equally exposednon-smoker. This multiplicable effect also appliesif the exposed person subsequently smokes, e.g. ifyoung child who has been exposed to asbestossubsequently smokes. Conversely, for a smokerwho has been exposed to asbestos, the lung cancerrisk can be reduced if the smoker stops smokingor reduces his consumption of tobacco. There isalso a latent period with mesothelioma, generallyabout 40 years, but can range from 5 to 80 years.However, latent periods of less than 10 years arerare.

The risk of developing mesothelioma increases asthe time since exposure to asbestos to the power3-4, e.g. Doll and Peto (1985). For example, themesothelioma risk to age 80 for someone firstexposed at age 20 is about twice as high as forsomeone similarly exposed from age 30. If a childis exposed to asbestos from birth, themesothelioma risk is about a factor of 2.5 higherthan from age 20, from Doll and Peto (1985). Ageat the time of exposure is therefore particularlyimportant for children as they have a higherprobability than adults of living long enough todevelop mesothelioma. A further problem is thatif children are exposed to asbestos in the home,they may be exposed for up to 20 hours/day, ~350days/year. For a given airborne fibreconcentration, a pre-school child may therefore

A presentation by Marius Urbonas, Head ofDepartment of Public Health Safety Expertise, State

Environmental Health Centre, Lithuania (Chairman ofLithuanian Union of Hygienists and Epidemiologists)

on the IFEH Website www.ifeh.org

The presentation is entitled 83/477/EEC, 91/382/EECand 2003/18/EC: Protection of Workers from Risksrelated to the Exposure to Asbestos – Problems andExperience from Lithuania – and was given at the

Seminar on OHS Prevention Culture, OHSManagement System.

This article was first published in the Royal EnvironmentalHealth Institute of Scotland Journal


17

have an about 4 times higher cumulative exposurethan an adult occupationally exposed for 40hours/week for 45 weeks/year. This extendedexposure effect is multiplicative with the ageeffect: a pre-school child exposed in the home for20 hours/day for 5 years is therefore at a 10 timeshigher risk of developing mesothelioma by age 80than an equally exposed 20 year-old adult atwork.

There are two different classes of asbestos,serpentine and amphibole, and six different typesof asbestos, chrysotile – “white asbestos” is aserpentine, and crocidolite – “blue asbestos”,amosite – “brown asbestos”, anthophyllite, alsosometimes called “white asbestos”, fibroustremolite and fibrous actinolite are all amphiboles.Note that non-fibrous tremolite and actinolite arecommon minerals.

Not all types of asbestos are equally hazardous.For a given exposure, the asbestosis risk is greaterwith crocidolite and amosite than with chrysotile.The mesothelioma risk with crocidolite is about 5times greater than with amosite and about 500times greater than with chrysotile. The asbestos-induced lung cancer risks with crocidolite andamosite are 10-50 times greater than withchrysotile, Hodgson and Darnton (2000). Fibroustremolite and fibrous actinolite can be consideredas having the same potency for causingmesothelioma as crocidolite.

All asbestos used in the UK was imported. Totalimports of asbestos into the UK were about150,000 tonnes of crocidolite, about 600,000tonnes of amosite and about 6? million tonnes ofchrysotile. A small quantity of anthophyllite wasalso imported. Fibrous tremolite and actinolitewere not commercially used in the UK but werepresent as naturally occurring contaminants inchrysotile from some sources, e.g. chrysotile fromQuebec could contain up to about 4% by weightof tremolite. Fibrous tremolite is also present as anatural contaminant of talcum powder andvermiculite from some mines and has causednumerous mesotheliomas in such areas.

Crocidolite was used in thermal and acousticinsulation products in sprayed or bulk form, inmattress, (bags with crocidolite or chrysotiletextile covers and generally filled with crocidoliteor amosite fibres), in building boards, in high-pressure water and sewerage pipes and in wartimeand post-war military gas mask filters. Amosite

was used in similar products as crocidolite butwas also used in preformed insulation sectionsand slabs and in Asbestos Insulation Boards(AIB). It can be estimated that about 140 millionsquare metres of AIB were manufactured in theUK between about 1950 and about 1980. Suchboards contained 15-50% by weight of amositeand some pre-formed pipe sections and slabscontained up to about 80% by weight of amosite.Chrysotile was primarily used in asbestos cementproducts, which can contain up to about 15% byweight of asbestos, and in low-density fireresistant boards, which were widely incorporatedin fire doors and other fire resistant panels. Fromthe latter 1950s through the 1960s crocidolite wasadded to asbestos cement products at 1-3% offibre content to increase production. Given the500-fold higher mesothelioma risk withcrocidolite compared with chrysotile, a 1%crocidolite content of the fibre content in asbestoscement products increases the mesothelioma riskby about a factor of 6 as compared withcrocidolite-free products. Asbestos cementproducts should therefore always be assumed tocontain crocidolite unless it is known that thedates of manufacture post-date about 1975 orproper analysis has confirmed that such productscontain chrysotile only.

Sprayed materials containing crocidolite and/oramosite are very friable and can readily releasefibres. Bulk thermal insulation is commonlycalled “monkey dung” or “plastic” and generallycontains crocidolite and/or amosite, magnesiumcarbonate or calcium silicate and a binder, such asPortland cement. Poorly controlled removal ofsprayed crocidolite or amosite materials cangenerate upwards of 3,000 fibres/ml and the useof power tools on inadequately wetted crocidolitecan generate up to about 1,000 fibres/ml, Howieet al (1996). A short study by this author revealedthat the dry breakout of a single 4-foot by 8-footsheet of AIB and sweeping up the dry debriscould generate personal exposures of 50-75fibres/ml of amosite and could cause the releaseof 9,000,000,000 respirable airborne amositefibres. Even “trivial” activities such as stickingdrawing pins in AIB can release numerousairborne fibres: one drawing pin insertion andremoval can generate 2,000-6,000 respirablefibres.

HSE (2003) estimated that there had been about25,800 male mesothelioma deaths in Great Britainduring 1968-2001 and that between 2002 and

2050 there will be a further 55,000 male deaths.Assuming that female deaths occur at about 15%of the rate of male deaths, total mesotheliomadeaths to 2001 will have been about 30,000 with afurther about 63,000 between 2002 and 2050.

HSE’s above estimate is based on the assumptionthat current and future exposures to airborne fibresare very low. However, it must be appreciated thatat the incoming Control Limit of 0.1 fibres/ml forall types of asbestos, the risks are very substantial.For example, the lung cancer and mesotheliomaconsequences of exposure to 0.1 fibres/ml ofasbestos over a 20-year working period from age20 will be as below, from Hodgson and Darnton(2000):

Excess deaths per million to age 80 from 20 yearexposure to 0.1 f/ml from age 20

HSE (1989) assessed the social acceptability ofexcess deaths risks and concluded that a death riskof 1 in 1,000 per annum (1/million/yr) “is aboutthe most that is ordinarily accepted under modernconditions for workers in the UK and it seemsreasonable to adopt it as the dividing line betweenwhat is just tolerable and what is intolerable.”HSE (1989) introduced the concept of a“tolerable” risk as a risk arising from a processfrom which there is a benefit, e.g. as we all useelectricity, we must therefore all accept a level ofrisk in return. The upper boundary for “tolerable”risk was set at 10/million/yr and the boundary for“acceptable” risk was set at 1/million/yr.

Philosophically, is seems of extremely dubiousmorality for anyone to define as “just tolerable” alevel of risk to which he is not himself exposed. Itis therefore herein considered that no workershould be exposed to an occupational risk of morethan 10/million/yr.

If annual risk is taken as being the total riskdivided by the period over which that risk isaccumulated, i.e. the period of exposure, theannual risks for 5-year exposures from age 20 at0.1 fibres/ml are 5,300/million/year withcrocidolite, 800/million/year with amosite and120/million/year with chrysotile. That is, all above

risks are very substantially in excess of the“tolerable” boundary of 10/million/year.

From the above figures it is essential that allpersonal exposures be reduced to the lowesttechnically feasible level, and certainly tosubstantially less than 10% of the new ControlLimit of 0.1 fibres/ml, particularly for exposuresto crocidolite or amosite.

Limiting personal exposures to consistently lessthan 10% of the Control Limit will requirescrupulous adherence to new working methodsand rigorous enforcement of the incoming Controlof Asbestos at Work Regulations.

There are many situations where “ReassuranceSamples” are taken to assess airborne asbestosexposure levels in offices, schools and homes.Great Britain currently does not have anenvironmental limit for asbestos. However, HSE(2005) states that the Clearance Indicator criterionof 0.01 fibres/ml may “… also be used in theinterpretation of reassurance and backgroundsamples”. The Clearance Indicator is the airbornefibre concentration which must not be exceeded ifan asbestos enclosure is to be removed. This useof the Clearance Indicator is in directcontradiction to the Approved Code of Practice,HSE (2002), which states that: “The threshold ofless than 0.010 fibres/ml should be taken only as atransient indication of site cleanliness, inconjunction with visual inspection, and not as anacceptable permanent environmental level” (myitalics).

As the concentrations measured duringReassurance Sampling are effectively thepermanent exposure levels within the building, itis useful to assess the risks for adults and pre-school children exposed to this concentration forfive years on the assumption that the adults areexposed occupationally for about 1,800 hours peryear from age 20 and that pre-school children maybe exposed in the home for about 7,200 hours peryear from birth.

The mesothelioma and lung cancer risks fromsuch exposures are shown below, from Hodgsonand Darnton (2000) and Doll and Peto (1985):


18

Asbestos type Mesothelioma Lung cancer Total

Crocidolite 19,400 1,300 21,000

Amosite 2,700 1,300 4,000

Chrysotile 150 450 600

From the above it will be seen that theconsequences of residential exposure to 0.01fibres/ml for pre-school children are about a factorof 6 higher than for adults occupationally exposedat the same concentration and very substantially inexcess of the “tolerable” level of 10/million/yr forexposures to all types of asbestos.

It is concluded that unless occupational personalexposures are reduced to less than about 10% ofthe incoming Control Limit of 0.1 fibres/ml andresidential exposures for pre-school children arereduced to below less than 10% of the ClearanceIndicator of 0.01 fibres/ml, particularly forcrocidolite and amosite, the excess death risks willbe very substantially in excess of the “tolerable”level of 10/million/yr for exposures to all types ofasbestos and HSE’s assumed mesothelioma deathsto 2050 will be an underestimate.

REFERENCESDoll R and Peto J (1985) Asbestos Effects on health ofexposure to asbestos. Health and Safety Commission:London.Health and Safety Executive (2005) Asbestos: The analysts’guide for sampling, analysis and clearance procedures. HSG248. HSE Books: Sudbury.Health and Safety Executive (2003) Mesothelioma mortalityin Great Britain: estimating the future burden. HSE: Bootle.Health and Safety Executive (2002) Approved Code ofPractice: Work with asbestos insulation, asbestos coating andasbestos insulating board”. Fourth Edition, L28. HSE Books:Sudbury.Health and Safety Executive (1989) Risk criteria for land-useplanning in the vicinity of major industrial hazards. HMSO:London.Hodgson JT and Darnton A (2000) Quantitative risks ofmesothelioma and lung cancer in relation to asbestosexposure. Annals of Occupational Hygiene, 44: 565-602.Howie RM, Johnstone JBG, Weston P, Aitken RJ, Groat S(1996) Effectiveness of RPE during asbestos removal work.HSE Contract Research Report No. 112/1996. HSE Books:Sudbury.

GROUNDWATER QUALITY AND HEALTHRISKS IN ONNE COMMUNITY NEAR AFERTILIZER COMPLEX IN SOUTHERNNIGERIA

G. R .E .E Ana and M.K.C SridharDepartment of Epidemiology, Medical Statisticsand Environmental Health, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria

E-mail <[email protected]> Phone 08037146436

ABSTRACTThe quality of groundwater sources around thevicinity of a chemical fertilizer industry located inOnne about 30km from Port Harcourt wasassessed. The objective of this study was todetermine the extent of contamination ofgroundwater sources and their associated healthrisks in the host communities to the fertilizerIndustry. This was carried out by assessing thelevels of some physicochemical parameters usingmethods recommended by the American PublicHealth Association (APHA). Eight samples withappropriate controls were randomly obtained andanalyzed for parameters including pH,conductivity, phosphate, nitrate and total hardness.In addition, 100 human subjects selected randomlywere subjected to in-depth interview on theirhealth conditions within the communities. Thelaboratory results indicated the highestconductivity value of 582.0Ìs and an undetectablefree ammonia level for one of the control samples.Also there was relatively higher levels of nitrate(>1.0mg/1), phosphate (2.22mg/1) and totalhardness (111.3mg/1) among some ground watersamples even though they were within acceptableguideline values .The survey results indicated that


19

Exposees Asbestos type Mesothelioma Lung cancer Total Risk/million/yr

AdultsCrocidoliteAmositeChrysotile

1,24018650

1515–

1,26020050

2554010

Pre-schoolchildren

CrocidoliteAmositeChrysotile

8,1601,224–

104104–

8,2601,330326

1,65026665

Excess death risks per million to age 80 from 5-year exposures to 0.01 f/ml

apart from malaria, which recorded the highestincidence, GIT disorders 20(20%) and skinirritation16 (16%) were the most reported healthproblems in the communities. This study indicatesthat present level of groundwater pollution withnitrogenous substances is minimal. However,other contaminants such as ionic species may beassociated with the high incidence of GIT andSkin disorders recorded in the communities.

Key Words: ‘Fertilizer Industry’, ‘GroundwaterPollution’, ‘GIT Disorders’, Onne and Nigeria.

INTRODUCTIONGroundwater constitutes nature’s largest and mostvaluable source of drinking water. However, itspotability and availability remain very serious areaof concerns for many great nations especially theindustrialized ones. The composition ofgroundwater is dependent on the kind of soils andgeological materials rich in minerals. The amountof these substances makes it potable or hardlypotable (Patrick and Ford, 1990)

Often, a number of anthropogenic activitiescontribute to the adverse changes in thecomposition of groundwater sources. Some ofthese include increase in nitrate and phosphateconcentration arising from extensive fertilization(Gazela et al, 1974); large number of coliforms,high concentration of nitrates, chloride andphosphate resulting from sewage infiltration(Sridhar and Pillai, 1973). Sometimes, industrialeffluents also constitute potential source ofcontamination of groundwater sources. Recently,studies on ground water contamination haveelucidated implicitly inputs from non-industrialand industrial sources with the latter accountingfor more than 40% of these cases.

In Nigeria, limited evidence abound as to thestatus of ground water supplies especially thosebordering industrial communities. The groundwater sources that serve the host communities toNigeria’s most complex chemical fertilizerindustry are in no way any exception.

These water sources though complementary to themore abundant and readily utilized surface watersources could pose public health risk if theirquality is of modicum standards. The overallobjective of this study is underscored by the needto assess the quality of the available ground watersources and the attendant health risks in the hostcommunities to the fertilizer industry.

METHODOLOGYThe Study Area

The study was conducted within the vicinity of theultra-modern fertilizer complex at Onne, locatedin the southern part of Nigeria between 4.49Ô and4.5 Ô North and about 6.59 Ô and 7.0 Ô east ofthe Greenwich Meridian and about 30km fromPort Harcourt, Rivers State. The fertilizer complexis bounded on the west by Okrika creek, which isthe major receiving water body for the planteffluents which are rich in nitrogenous andphosphorous compounds, Okrika communities andmangrove swamps; on the east by Onnecommunities and farmlands where most of thesamples were obtained; and on the south by theFederal Ocean terminal, Ele and Owuogono.

MaterialsEight ground water samples were collected cross-sectionally from eight points distributed randomlyaround the fertilizer complex within a radius of5km. Two of the samples, from bore holes, werecollected from the plant complex and staff villageabout 1km apart, while four samples from threehand dug wells and one bore hole were collectedfrom Alegeor, Agbeta and Ogoloma Villages ofOnne town (each about 500m apart). Two controlsamples were collected from Diobu area of PortHarcourt, 30km away from the study area.

MethodsMethods used in assessing the ground water qualitywere classified into physical and chemical methods.Prior to this, the general features of the variouswater sources were documented. For the physicalmethods, parameters such as colour, odour,temperature, pH and conductivity were determined.Colour and odour determination were carried outaccording to standard methods. Temperature wasmeasured in-situ using standard laboratory sizethermometer graduated in degrees Celsius (˚O C).Measurement of pH value was carried out by probemethod with a standard calibrated pH meter model3020 made by Jenway, U.K Conductivity wasmeasured using a conductivity meter model 4010made by Jenway, U.K.

The following chemical parameters weremeasured: dissolved oxygen (DO), urea, freeammonia, chloride, nitrate, phosphate, totalhardness, iron and zinc. The dissolved oxygenwas determined by using a calibrated standard DOmeter model 50B made by YSI, U.K The chloride,nitrate and phosphate levels were determined


20

spectrophotometrically according to mercuricnitrate, phenoldisulfonic acid and sulphatedigestion standard methods, respectively. Thetotal (calcium) hardness level was determinedusing EDTA titrimetric method while the zinc andiron concentration were determinedspectrophotometrically using zincon andphenanthroline methods respectively as describedby standard methods (APHA,1992)In addition to these laboratory methods, a healthsurvey involving in-depth interview with 100human subjects randomly chosen in thecommunity was carried out .This interviewfocused primarily on sources of water, uses ofwater and prevailing health conditions andoutcomes among individuals in the community.Data obtained was processed and subjected todescriptive statistical analysis.

RESULTS AND DISCUSSIONThe general features for the groundwater sources

are given in Table 1.0.The results of the physicaland chemical analyses as shown in Table 2.0indicate that with the exception of samples 4 and 5that were slightly turbid and brownish all othersamples were colourless. Odour was not perceivedin most of the samples except for samples 4 and 5,which were slightly rusty and rusty respectively.The control sample 2 from Port Harcourt townrecorded the highest conductivity value of582.0µs. Free ammonia was not detectable in anyof the samples. Only samples 7 and 8 from theneighbouring villages recorded nitrate levelsabove 1.0mg/1. Sample 7 recorded the highestphosphate level of 2.39mg/1. The highestconcentration of calcium hardness was recordedfor sample 5 from the village. The health surveyindicated that although malaria recorded thehighest incidence, other cases such as skin andGIT infections were significantly high in thecommunities based on the reports of therespondents as shown in Figure 1.


21

Sample sources

Location Nature of sources Remarks

1 Port Harcourt Town (30km) Bore hole Good sanitary condition

2. Port Harcourt Town (32km) Shallow wellCover presentDepth 3.9mWidth 0.9mParapet 1.0Apron present

Fair Sanitary condition

3. Plant Complex (1km) Bore hole Very good sanitary condition4. Estate (2km) Bore hole Very good sanitary condition5. Ogoloma village (4km) Bore hole (Hand pump) Water was brownish in colour6. Ogoloma village(3.5km) Shallow well

Cover presentDepth 7.25mWidth 1 mParapet 0.5mApron present

Algal growths on the upperLinning of the well

7. Alegeor village(3km Shallow wellCover presentDepth 6.481mWidth 0.81mParapet 0.45mApron present

No algal growths on the side ofthe well

8. Aleta village (2.5km) Shallow wellCover presentDepth 6.48mWidth 0.81mParapet 0.45mApron present

No algal growths on the sides ofthe well

Table 1.0: General Features of Groundwater sources:

Table 2.0 Physicochemical Parameters for Groundwater Sources

Port Harcourt (PH); Brownish (B); Clear (C); Slightly Turbid (ST); Slightly Rusty (SR); Rusty(R ); Not Detectable (ND)

Sampling PointParameters

1P.H TownBore Hole(control 1)

2P.H TownBore hole(control 2)

3Plant Borehole

4PlantEstate Borehole

5VillageShallowwell

6VillageShallowwell

7VillageShallowwell

8VillageShallowwell

WHOGuidelineValue

Colour C C C ST B C C C 5 units

Odour ND ND ND SR R ND ND ND Unobjecti-onable

Temperature(oC) 26.0 26.3 26.0 28.5 28.0 28.5 28.0 28.5 <40oC

pH value 5.24 5.24 6.85 6.85 6.55 6.90 7.44 7.38 6.79 7-8.5

Conductivity(ms) 146.6 582.0 22.8 13.5 16.2 347.2 222.7 72.5 –

DO (mg/l) 6.60 6.60 6.88 6.40 7.20 6.60 7.07 6.60 6.63 8mg/l

Chloride (mg/l) 30.3 126 3.08 2.56 ND 25.64 9.74 7.69 200mg/l

Nitrate (mg/l) 0.551 0.551 0.735 0.857 ND 0.673 1.591 1.071 50mg/l

Phosphate (mg/l) 1.51 1.62 0.366 0.937 ND 0.427 2.391 2.22 –

Free Ammonia ND ND ND ND ND ND ND ND –

Total Hardness (mg/l) 18.87 2.97 2.81 9.037 15.94 0.427 2.391 2.22 100mg/l

Iron (mg/l) 0.037 0.141 0.005 0.065 0.297 111.3 82.98 11.22 0.1mg/l

Zinc (mg/l) 1.139 0.853 1.07 1.134 0.295 1.79 1.323 1.257 5.0mg/l


22

Fig 1.0 Health Status of communities

The assessment of quality of ground watersobtained near the fertilizer industry showed thatall the samples including controls had clearappearance except for the borehole samples in theestate and the village, which were slightlycoloured. This condition was found to beassociated with the rusty pipes. Odour,temperature and pH values for all the sampleswere within the WHO permissible limits.However, the high conductivity values recordedfor control sample 2 and some of the villagesamples were an indication of probable intrusionof salts from the brackish aquatic ecosystemsurrounding the Onne and Port Harcourtenvironments respectively. This may have haddirect bearing with the GIT infections and skinmorbidities recorded in the community.

Also results indicated appreciable DO valuesranging from 6.60mg/l to 7.20mg/l whencompared to WHO’s recommended level of8.0mg/1 for potable water (WHO, 1995). The freeammonia levels were not detectable in any of thesamples. Nitrate levels were within WHOpermissible level but were comparatively higher inthe village samples suggesting nitrogenous inputsfrom either domestic activities and/or acombination of that with the industrial discharges.This implies that though ammonia nitrogen is notpresent, the current level of nitrate contaminationdoes not pose any health hazard thus allaying anyfears of possible nitrate poisoning in thecommunity (Jackson et al 1990). Nevertheless, itis not unlikely that the risk of such a conditionmay not occur if the pollution load increases andsustainable environmental practices diminish infuture.

Furthermore, the values for chloride, totalhardness and phosphate levels were not significantwhen compared to WHO’s highest desirable levelof 200mg/l for chloride and 100mg/l for totalhardness respectively. The levels of metals likezinc were very low in comparison with WHO’shighest desirable level of 0. 1mg in contrast tohighly significant levels of zinc in some samplesas compared with WHO’s highest desirable levelof 5.0mg/l.

The high malaria incidence in the community istypical of any tropical environment. However, thehigh incidence of skin and GIT morbidities mayhave been attributed to exposure to water sources,whose quality has been eroded due to presence ofsome inorganic contaminants. Other minor

morbidity conditions such as arthritis and sexuallytransmitted diseases (STD’s) were also reportedand these were higher among women.

CONCLUSIONThis study reveals that most of the water sourcesin Onne are potable with very minimal impactfrom nitrogenous substances. Nevertheless, thereare strong indications that apart from malaria,which recorded the highest incidence in thecommunity, other highly reported morbiditiesassociated with skin and GIT may have beenassociated with the presence of inorganic-basedcontaminants in the groundwater. This constitutesan area for in-depth research in the future.

REFERENCESAmerican Public HealthAssociation(1992)Standard methods for theexamination of water and waste water., 17thedition.Gazela, S; Melioris, L and Probity, A. (1974)“Hydrogeology and Environmental protection:Mineral Solvac; 6 (3) 239-48.Jackson, M.H, Morris G.P;, Smith, P.G. andCrawford, J.F. (1989) “environmental HealthReference Book” By Butterworth-Heinemann,Printed and rolled by Hartnolls Ltd BodminCornwall pp 8/3-11/20.Patrick, R.E and Ford, J.Q (1990): “Groundwatercontamination in the United State, second edition,Philadelphia. A Publication of UNEP-Industryand Environment, pp 29-30Smith, G.E (1967) “Fertilizer Nutrients ascontaminants in water supplies” published inAmerica. As advance sci (85). 173-86.Sridhar, M.K.C and Pillai, S.C. (1973) “Pollutionof ground water at Banglore”: Proceedings of theSeminar on Environmental Pollution CentralPublic Health Engineering Research Institute,Nagpur, 59-70.World Health Organisation (WHO (1995):“Guidelines for Drinking Quality Water “2ndedition. Vol. 1. Geneva, pp 174-180..

ACKNOWLEDGEMENTSWe express our sincere gratitude to themanagement of National Fertilizer Company ofNigeria (NAFCON) limited for granting us accessto its facility for the purpose of conducting thisresearch.


23

Assessment and Monitoring ofChemical Water Quality Parametersin the Mbabane River: Swaziland

S.J. NKAMBULE ( Dipl., B.Sc. (Hons), M.Sc.)University of SwazilandFaculty of Health Sciences Department ofEnvironmental Health Sciences

ABSTRACT:A preliminary assessment and monitoring ofMbabane river water quality was done betweenJanuary and December 2002. The river flowsthroughout Mbabane collecting surface run-offsfrom residential, urban and different type ofindustrial sites. Concentration and level ofchemical water quality parameters namely,Biochemical Oxygen Demand (BOD), ortho-phosphates, nitrates, sulphates, ammonia,chlorides and dissolved oxygen were monitored atfour different sites which were identified along theriver. Site one upstream as a control site, site twoat the industrial site, site three downstream ofwaste stabilisation ponds discharge and site four10km downstream, to assess the recovery rate ofthe river.

The study shows that during the period ofsampling, the concentration levels of chemicalparameters eg. ammonia at 1.8mg/l and BOD at9.2 mg/l exceeded levels stipulated in The WaterAct, Water Quality Standards. This pollution mayhave been attributed to leaks and overflow in thesewerage networks along the river. Theconcentration of the other parameters had notreached alarming proportion but showed steadyrising level, which is a cause for concern, thus

discharges from nearby industries need to beclosely and continuously monitored.

This study shows that chemical pollution in theMbabane river poses a threat to the environmentespecially the aquatic life and is a health hazard tothe people who depend on the river for their dailyactivities.

INTRODUCTION AND LITERATUREREVIEW.A normal healthy river has a balance of plants andanimal life presented by great diversity of species.Water is critical to the survival of life includingplants and animals and man is no exception. Ifthe water is polluted aquatic life will not survive,humans will also be affected due to toxic andhazardous pollutants in the water systems whenused for domestic, habitations, agriculturalactivities etc. Water-borne and other water relateddiseases will affect water users down stream(Vissman and Hammer, 1998).

History shows many occasion where agriculturaldevelopment has been hindered by lack of watersupplies due to conflicts between landowners andsettlers, which has occurred in numerous parts ofthe world and other conflicts in relation to watersupplied can arise because of effects which humanand industrial wastes can have on the water(Tebbutt, 1998). This means that the importanceof water as a natural resource, which requirescareful management and monitoring, must beuniversally recognised. Although Nature often hasgreat ability to recover from environmentaldamage, the growing demands on water resourcesnecessitate the professional application offundamental knowledge about the water cycle toensure maintenance of quality and quantity.

Rivers are a major source of water supply fordomestic and other municipal activities.Industries also rely on water to remove excessheat and satisfy their manufacturing processneeds. Unfortunately, the water that has been usedin all these activities will find its way back intothe river as their principal disposal pathway forwaste materials. The propagation of fish, shellfish and other aquatic life does not normallyrequire withdrawal of water from the source but isbased on utilisation in place (Lamb 1985). Associeties become more industrialised, the varietyof waste material increases and problems of waterquality become more difficult and demanding.The natural ability of the river to deal with a


24

certain degree of inevitably organic pollution fromits catchment is reduced. This may reduce thevalue of the water, or even make its use for certainpurposes impossible without substantial priortreatment. This situation may develop, forexample, when discharged waste waters diminishaesthetic benefits and reduce or eliminate downstream fisheries. It may also creates lessacceptable raw water quality for municipal orindustrial supplies, or reduce the ability of thestream to assimilate potential pollutants fromother discharges.

In order to understand the river system and itsinfluence on water quality, it is essential that themechanism governing pollution and self-purification processes are also understood. In thisstudy chemical parameters were investigated in aneffort to evaluate their concentration and effectupon quality status of the river. Sources ofpollution into rivers, legislation and otherdocumentary sources to control pollution werealso studied.

Associated with the increase in population size, isthe increase in industries. Studies have shownthat in industries there are by-products wastes oreffluent, which are discharged to rivers. With thewidespread use of organic and inorganicchemicals such as herbicides and insecticides inagriculture, it is inevitable that some of these findtheir way into fresh water systems (Miller, 2000).Some pollutants do not break down readily in thenatural environment, such that once taken by aplant or animal in a food chain, they pass andaccumulate in the highest members of the chain(Willonghby, 1976). As Swaziland is a growingcountry, there are also industries that have beenestablished and developed. These industriesgenerate effluent and excessive discharges ofeffluent into a river cause deterioration in itsquality. These are manifest in the loss ofdissolved oxygen, increased turbidity and changein the flora and fauna, occurrence of smell; as aresult of river pollution.

River and environmental pollution by heavymetals became widely recognised with theMimmota disaster in Japan, when between 1953and 1960 several thousands of people sufferedmercury poisoning from eating fish caught fromMimmota Bay, which was receiving mercury froma vinyl chloride plant (Mason, 1981). A river isconsidered to be polluted when it contains such alarge amount of organic matter that the oxygen in

the water is greatly depleted, due to microbialactivity. The discharge of effluent at one pointinto a river can lead to such conditions.

There are several sources from which potentialpollutants may enter watercourses and these canbe categorised into two main groups namely:a) Point Sources &b) Non- Point Sources (diffuse)

For effective control and monitoring of pollution,a clear understanding of these sources as well asthe type of material they may contribute into freshwater is essential. Point sources are characterisedby the fact that effluent is conveyed in a definedchannel. They posses the property that the totalload of pollutants can be determined by samplingand flow measurement at the point of entry to areceiving watercourse (Kalderman, 2000). Thediffuse or non-point sources discharges are mainlythrough run-off where the total flow cannot bemeasured or sampled directly or even readilyobserved at a single point. It also make it difficultto apply treatment, or monitoring and suitable forregulation by the effluent limitations approach(Nemerous and Avijit, 1991). For this reasonregulation must centre on the means of controland prevention measures.

Water in rivers is the usual recipient of industrialpollution because disposal of wastes into thebodies is cheap and convenient. Eventually thesewastes may accumulate to a point where theybecome dangerous. The Peleng river in Botswanafor example, has been polluted with liquid wasteto the point where fish and reeds disappeared andboreholes, which provided drinking water forPeleng Village had to be closed (Segosebe andVan der Post, 1991).

Industrial waste may also be dumped on factoryproperties, where they can wash into surface watersupplies especially rivers or into groundwater.Became of this kind of surface run-off from factoriesand laundries in Lesotho, Maseru’s main watersupply is contaminated with lead six times aboveWHO Standards (Gentler and Ambrose, 1992).

Pulp and paper mills are among the worstindustrial polluters. Production of pulp and paperrequires large quantities of water. Pulp mills usestrong chemicals such as chlorine, to soften woodpulp and bleach it white. Treatment of theeffluent does not remove all the contaminants(Vissman and Hammer, 1998).


25

Treatment of wastewater at the Swazi Paper Mills(SPM) on the Great Usuthu river in Swaziland, iswell below standard according to the SwaziGovernment. Phenols, which are by-products ofpulp production, have increased steadily since1998 and now average about four times abovestandard. Phenols accumulate rapidly in fish,giving them a strong odour and taste. Paper fibresare discharged into the river together with theeffluent and now carpet the bottom of the riverwhere they will continue to rot and rob the waterof oxygen (Mtetwa, 1992).

Even much a simple matter as blockage of waterpassages in the bottom gravel by decaying debriscan reduce the survival of young fish and fisheggs (Mhlanga 1994).

The overall impact of pollution on environmentand human health in Swaziland is difficult tojudge because there is no baseline information.No long-term studies of pollutants have beenundertaken at national level, and appropriatecontrol and monitoring mechanism are not inplace or are poorly enforced. In some cases,pollution is not monitored. However, a review ofsome individual sources of pollution and theirriver impacts is being done and provides a startingpoint for assessment.

METHODOLOGY

The following parameters, namely biochemicaloxygen demand, orthophosphates, nitrates,sulphates, ammonia, chlorides and dissolvedoxygen were monitored at four (4) samplingpoints along the river basin.

Sampling PointsThis site in approximately 4 km upstream ofMbabane city, before the river reaches theindustrial site. Water samples were taken at a lowlevel bridge. This site was used as a control pointfor the experiment since at this point no effluenthas been discharged into the river.

Site IThis site is approximately 4 km upstream ofMbabane City, before the river reaches theindustrial site. Water samples were taken at a lowlevel bridge. This site was used as a control pointfor the experiment since at this point no effluenthas been discharged into the river.

Site 2.This sampling point is located after the river haspassed all the possible sources of pollution afterthe industrial areas. The site was to assess theconcentrations of the chemical parameters and itwas the main point of the experiment.

Site 3This sampling station is located 3km downstreamof the industrial site. This point was to assess thedischarge effluent from waste stabilisation pondswhich service the whole of Mbabane city and peri-urban area.

Site 4This site is about 18km downstream and sampleswere taken below a bridge were there is a gaugingstation though was not functioning during thestudy period. The reason for this site was on theunderstanding that effluent from the industrial siteand ponds would have mixed well with the riverwater and that the distance was considered to haveallowed recovery of the river and some tributariesjoining the river would have some dilution effecton the water to reduce the burden of the pollution.

Sampling ProcedureWater samples were collected using 1-litrepolythylene plastic bottles, which were pre-washed and rinsed with de-ionised water, andduring sampling the bottles were thoroughlywashed and rinsed with water to be sampled.Samples were collected and analysed the sameday; if not finished they were stored at 4˚crefrigeration and analysed the following day.

The samples were collected over a period of 12months from January to December 2002 at regularinterval and sampling was done between 9:00 amand 12noon as this was the peak operationalperiod for all the industries. In each samplingpoint, three samples were collected (triplicate) incase there were errors and mistakes


26

Spatial water quality variations.The results in respect to the spatial water qualityvariation are shown on Figures 2 and 3. Site 3 waslocated on a small tributary of the river, andrepresents the impact of the wastewater treatmentplant discharge. The magnitude of pollution at thispoint is considerably higher than in MbabaneRiver. This could be explained not only by theinfluence of the plant but also because of therelatively low water quantity in this tributary,which does not allow for considerable dilution ofthe effluent. The discharge from the plant couldnot be considered as a well defined point source ofpollution. The ponds are full with sediments andvegetation has grown at separated spots.Wastewater is flowing along naturally formedchannels and small ponds, the banks of the pondsare not well defined, and the inlet and outletfacilities are clogged and do not function properly.Due to this, the effluent finds its way to the streamat several, naturally formed locations, but not onlyat the discharge outlet. As a result, the treatment

effect in the ponds is limited to partialsedimentation and retention of the coarse materialand a fraction of the suspended solids. It could beexpected that the washout of pollutantsconstituents during peak flow rates would be high.The high values of ammonia, BOD5, and the low

DO values could be explained by the contributionfrom the pond effluent where anaerobic conditionsexit most probably. Additional measurements inrespect to this parameter, could clarify thiscontradiction. Most probably, it could beexplained by a human error during the results’processing stage, because the chlorides andsulfates variation (Fig. 2) show a completelydifferent trend. Chlorides concentrations showconsiderable increase at sites 2 and 3, with amaximum concentration at site 3. Chloride, beinga conservative constituent, could reduce its valuefrom site 3 to site 4 due to dilution only. Sulfatesshow a similar trend, however the maximumconcentration was found at site 2, which could beassociated with industrial discharges.


27

Parameter Units Standards methods for Examination of water and wastewater(ALPHA 19TH Ed)

Biochemical Oxygen demandOrthophosphateDissolved OxygenNitratesSulphateChloridesAmmonia

Mg/lMg/lMg/lMg/lMg/lMg/lMg/l

Incubation for 5 days @20˚cModified Hach Calorimetric Method (CSIR, SA) DD MeterUV Spectrophotometer at 220nmTurbid metric MethodArgentometric MethodNesslerization Method (Direct and Following Distillation)

Table 1: Methods for Chemical Analysis

Parameter Unit Site 1 Site 2 Site 3 Site 4

BODOrthophosphateDissolved OxygenNitratesSulphateAmmonia

Chlorides

Mg/lMg/lMg/lMg/lMg/lMg/lMg/L

2.750.356.540.90.2002.72

3.972.226.836.955.980.1810.23

9.174.03.8113.261.401.7812.05

4.571.25.83.1610.480.752.54

Laboratory Analysis:The standard methods for the examination of water and waste water, 19th edition Washington, AmericanPublic Health Association were used for the analysis.The table below shows the methods which were used.

RESULTS AND DISCUSSION:The discussion is based on the average values(per sampling site) of the determined parameter. Table 2:below shows the average values.

Figure 2. Spatial variation of general pollutantconstituents in Mbabane River (mean values withStandard deviation shown as numerical value for n= 8)

Figure 3. Spatial variation of DO, nutrients andbacteriological contamination in Mbabane River(mean values with Standard deviation shown asnumerical value for n = 8)

The results of the Duncan’s test for statisticallysignificant difference of the mean values amongthe different sampling locations are presented inTable 2. The test is performed based on 8observations for all sampling locations andparameters, at a “·” value of 0.05. The ranking ofthe mean values is presented with capital lettersfrom A to D in decreasing order. Mean valuesdenominated with the same letter are notsignificantly different.

Table 3: Results of test for significant differenceof mean water quality concentrations and ranking.

Parameter Site 1 Site 2 Site 3 Site 4DO (mg/l) AB A C BBOD5 (mg/l) C BC A BNitrate (mg/l) D B A CAmmonia (mg/l) C C A BOrtho-P (mg/l) D B A CChlorides (mg/l) B A A BSulfates (mg/l) C A B C

In respect to organic pollution, the spatialvariation is similar with a well-pronouncedinfluence of the ponds effluent. The spatialvariation of DO confirms this trend, with thelowest concentrations measured at site 3. Ingeneral, it was found that the urban runoff doesnot influence significantly the river water qualityin terms of organic pollution. As the City islocated in a hilly mountainous area, the river flowis relatively rapid, which allows for good aeration,and this explains the relatively high DOconcentrations, and indicates to a potentially highself-purification capacity.

Nutrients variations follow the trend with thehighest concentrations of the three observedparameters at site 3. The significantly increasedconcentrations of nutrients at site 2 could beassociated with informal discharges from blockedsewer systems. It is also possible that some of theindustries are contributing as well. The highestconcentration, observed at site 3, has alarming valueand is attributed to the malfunctioning of thetreatment plant. The observed nitrate concentrationsare very high, compared to other similar cases, andare difficult to explain. It could be expected thatwith prevailing anaerobic conditions at the treatmentplant, nitrification processes would be suppressed,leading to lower nitrate concentrations. It is possiblethat the generally high DO concentrations due to thesteep slope, could help in boosting this process.Additional investigations should be performed todetermine the source of the nitrates observed duringthis study.

In general, significant increase in the water qualityconcentrations between the control point and sites2 and 3 was found in respect to almost allmeasured parameters, showing the presence ofdiffuse pollution from urban runoff. The relativelylow pollutant constituents at site 4 could beassociated with dilution from additional tributariesand partial self purification due to the high DOvalues.


28


29

Assessing and Managing diffuse pollution ofMbabane RiverDuring the period of study the water qualitylegislation of the country was under revision.Comparison with the suggested draft river waterquality standards shows high level of pollution ofthe stream, which receives the effluents from thetreatment plant The BOD5 limiting value of 5 mg/lwas exceeded at site 3 only. In respect toammonia, the stipulated limit was 0.08 mg/l and itwas exceeded at sites 3 and 4. Orto-P values wereexceeded at sites 2 and 3.

Nitrate limiting value (50 mg/l) is highercompared to other regulatory instruments, whichrecommend a 10-mg/l threshold (WHO 1984,Viljoen 1992, WWEDR 2000), and was notexceeded at any of the tested locations. It could bestated that at site 4, where river water could beused directly for domestic purposes, the waterquality was not exceeding the maximumpermissible values in respect to the testedparameters,except for ammonia.

The results of this study shows that the majorsources associated with diffuse pollution ofMbabane River (site 2) are associated with urbanrunoff from industrial sites, residential areas (interms of informal sewage discharges) and solidwastes depositions along the river bed and banks.Comparing with regulatory documents, it could bestated that the extent of the pollution is notalarming and is pronounced in respect to ortho-P.The major source of pollution in respect to theorganic and bacteriological pollution and nutrientshas been contributed by the malfunctioning of thetreatment plant (site 3).

The enforcement of the new regulatoryinstruments would require the implementation of aregular and continuous monitoring program, inorder to control the river water quality status andto enforce them. This study could be regarded as apreliminary survey for the establishment of suchprogram. In this aspect, the followingrecommendations could be made:

Considering the fact that Mbabane Riverdownstream the City use its water for domesticpurposes without pretreatment a stringentmonitoring program should be implemented inorder to control river water quality in terms ofseasonal variations and long-term trends. Carefulconsideration of different possible pollutionsources, from industrial enterprises could help to

develop an optimal choice of parameters(Ongeley, 1998). The information collected couldserve to justify management decisions in respectto pollution prevention and provide warning todownstream users in cases of high concentrationsof selected pollutants.

Monitoring network – in addition to the locationsin this study, sampling sites could be establishedalong the Pholinjane stream (after the industrialsite and the City center) and on Mbabane Riverafter the confluence of the stream collecting thedischarge of the treatment plant.

Parameters tested- additional parameters in respectto toxic substances should be included in themonitoring program, such as toxic metals, greaseand oil, selected synthetic organic compounds andtrace elements.

Laboratory backup – the proposed extendedmonitoring program would require correspondingback up in terms of laboratory facilities,equipment and trained personnel.

Quality assurance and records – these two aspectsneed to be given specific emphasis in order toobtain reliable data and to store it correspondinglyin an easy to use and comprehensive way.

The management aspects related to the diffusepollution problems of Mbabane River require amulti-disciplinary approach and theimplementation of technical, social andeducational activities. The following problemsrequire specific and urgent attention:

The status of the treatment plant – it should begiven priority, as it is the major source ofpollution of Mbabane River. During the period ofstudy the reconstruction of this facility wasenvisaged. The plant is located in a narrow valley,with very steep slopes of the surrounding hills.The original choice of a stabilization pond systemcould not be evaluated as very appropriate, as theplace is difficult to access and in addition there isnot enough space for expansion. Thereconstruction of the plant should look at theprovision of a more compact treatment scheme,where the existing ponds could be cleaned andtransformed into a wetland system for effluentpolishing. Special attention should be given to aproper access road in order to provide for thesmooth operation and maintenance of the plant.The implementation of such a management


30

decision would require the provision of thenecessary funding, for the completion of thewhole project including the design, constructionand initial operation phases, together with theproper training of the required human resourcesfor the plant operation.

The status of the solid waste management – thiscould be classified as other serious source ofdiffuse pollution. The proper organization of therefuse collection, provisions for refuse containersat all important public places, and the properdisposal and treatment of the collected solid wasteforms the technical base for a successful solution.However, this problem has a social aspect as well,and needs to be backed-up by a well-organizededucational and public awareness program.

Informal discharges from industrial sites,residential, institutional and commercial areas –the technical solutions of this aspect includeregular inspections and control of water quality,which could help to identify the most importantpolluters. Existing municipal by-laws should makeprovision and basis for such activities and shouldbe supported by the necessary institutional set-upand laboratory facilities. However, no technical ormanagerial solution could succeed if the there isno appropriate social behaviour, awareness andunderstanding about the risks of informaldischarges and the possible effects on the whole ofsociety. Therefore, the parallel development andimplementation of such programs is an importantrequirement for successful solutions of theproblems associated with diffuse pollution ofMbabane River.

ConclusionsThe study presented shows that the diffusepollution problems of river water quality havecommon grounds and sources. Therefore,pollution management and abatement measurescould have common bases for solutions as well, interms of general approaches, methods andregulatory instruments.

The study focused on the stretch of the Riverpassing through the City of Mbabane andreceiving all urban runoff and effluent discharges.The major pollution source was associated withthe effluents from the malfunctioning treatmentplant in terms of all tested nutrients, organicpollution and bacteriological contamination.Urban runoff, spreading of solid wastes along theriver banks and possible informal discharges from

the City have adverse impact of river waterquality, which is less pronounced, but is noticeablein terms of ortho-P, nitrate and bacteriologicalcontamination. About 20 km downstream the City,the river water quality did not show considerablepollution, which could be explained by dilutionfrom tributaries and partial self-purification.

The results of both studies should be considered inthe light of the mentioned limitations and as anevaluation of the spatial variation in respect toselected parameters only, given the availableresource at the time of the study. The presence ofindustrial discharges (usually without treatment orwith limited treatment) would require a moreextensive and regular monitoring program inrespect to some toxic elements, which mightcreate health problems for downstream users.

Acknowledgements The author would like to thank the management ofthe WREM program, through the “CollaborativeProgramme for Capacity Building in the WaterSector in Zimbabwe and the Southern AfricaRegion”, jointly executed by the Civil EngineeringDepartment -UZ, IWSD and IHE- Delft, for thefinancial support offered during this study. To thetechnical staff and the management of alllaboratories involved – thanks for their supportand understanding.

REFERENCES:Guenter, W. and Ambrose, D. (1992) Lesotho Environmentand Environment Law, National University of Lesotho,Roma, p. 211.

Kelderman, P. (2000) Water Quality Monitoring, IHE Delft /University of Zimbabwe Lecture notes.

Lamb, J.C. (1995) Water Quality and its Control: John andWiley and Sons (ISBN 0471800473).

Mason C.F. (1981) Biology of Freshwater Pollution.Longman Scientific and Technical, London, England.

Ongeley, E.D.( 1998). Modernization of water qualityprograms in developing countries: issues of relevancy andcost efficiency. Water Quality International, Sept./Oct.: 37-42.

Standard methods for the examination of water andwastewater( 1994). 19th edt. American Public HealthAssociation/ American Water Works Association/ WaterEnvironment federation, Washington DC, USA.

Miller, G.T. (2004) Living in the Environment, ThompsonBooks/ Cole, 13th edition.

Mhlanga, A. (1994) HCH and DDT Residue in theFreshwater Sardine (Kapenta) at the Ume River mouth,


31

Kariba, The Zimbabwe Science News, March/April, Vol.20, p46-49.

Mtetwa, V.S.B. (1992) River Pollution Studies in Swaziland:Assessment and Monitoring of Water Quality Parameters ofUsushwana (Little Usuthu) River, Unpublished report,University of Swaziland.

Nemerow, N.L. and Avijit, D. (1991) Industrial andHazardous Waste Treatment: Van Nostrand and Reinhold,New York (ISBN 0442319347)

Segosebe, E.M. and van der Post,C. (1991) Urban IndustrialSolid Waste Pollution in Botswana: Practice, Attitude andPolicy Recommendation, University of Botswana.

Tebbutt, T.H.Y. (1998) Principles of Water Quality Control,5th Edition. Butterworth/Heinemann.

Willoughby, A. (1976) Treatment of industrial Effluents,Hodder and Stongton (LTD) London, United Kingdom.

WWEDR (2000) Water (Waste and Effluent Disposal)Regulations, Statutory Instrument 274 of 2000, Republic ofZimbabwe.

World Health Organization (WHO). 1984 Guidelines fordrinking water, health criteria and other supportinginformation. Vol.2, Geneva: WHO.

Viljoen, F. C. 1992. Risks, Criteria and Water Quality.Municipal Engineer

NEHA OFFERS AVIAN-FLU-PANDEMIC ONLINE COURSETo assist public and environmental health professionals preparing for a possible flu pandemic,NEHA has partnered with NexPort Solutions to develop and deliver two online-training courseson avian influenza, Avian Flu Pandemic: Awareness for the Public Health professional and AvianFlu Pandemic: Preventive Measures Awareness.

Over the past several months H5N1 has moved along migratory bird flyways, from China andSoutheast Asia to over 25 countries across Central Asia, Europe, Africa, and India. The virus isalso changing, and its presence in Africa is increasing the likelihood that the virus may becometransmissible between humans, leading to a global pandemic on the order of the 1918 SpanishFlu Pandemic that killed over 50 million people.

Avian flu has the potential to not only trigger a global pandemic but also become a major, if notcatastrophic, public and environmental health issue. For these reasons, NEHA has worked todevelop two online-learning courses that serve to provide the student with a comprehensiveunderstanding of why the threat of a pandemic flu is of such concern. In addition, NEHA’sinteractions with both public and environmental health professionals have indicated that alimited understanding of this issue exists despite the significant role that these professionals willalmost surely play in any pandemic-flu response. The two courses will help to develop theawareness and understanding that is needed in order for this workforce to properly prepare forthis serious challenge.

Individuals who successfully pass the test at the conclusion of each course will receive 1hreecontinuing-education contact hours, 1.5 for each course.

The availability of these two courses also serves to inaugurate NEHA’s new online-learninguniversity. Through this new online university, visitors will be able to access courses such as thisone. In addition, they also will have access to an online library of resources, information streamsof current events, and other resources.

To purchase the course and enter the NEHA online university visit www.neha.org.

Note: While aimed at the public and environmental health profession, this course is of value toanyone interested in learning more about pandemic flu.

NATIONAL ENVIRONMENTAL HEALTH ASSOCIATION720 S. Colorado Blvd., Suite 970-S, Denver, CO 80246-1925

Phone: (303) 756-9090 Fax: (303) 691-9490 E-mail: [email protected]

www.ifeh.org

The new IFEH websiteit’s all yours – designed by IFEH

to be used by all members and other interested parties

e&hi volume 8 no. 1 2006 issn environment and health ...magazine of the international federation...

Documents