paraquat in surface water of some streams in mai chau...

Research ArticleParaquat in Surface Water of Some Streams in Mai ChauProvince the Northern Vietnam Concentrations Profiles andHuman Risk Assessments

Nguyen Thi Hue 12 Thi PhuongMai Nguyen1 Hoang Nam1 and Nguyen Hoang Tung 1

1 Institute of Environmental Technology VietnamAcademy of Science and Technology 18 Hoang Quoc Viet Cau Giay Hanoi Vietnam2Hanoi University of Science and Technology Vietnam Academy of Science and Technology 18 Hoang Quoc Viet Cau GiayHanoi Vietnam

Correspondence should be addressed to NguyenThi Hue nthue2003ietvnvn

Received 16 August 2017 Revised 25 December 2017 Accepted 31 December 2017 Published 25 February 2018

Academic Editor Jaime Villaverde

Copyright copy 2018 NguyenThiHue et alThis is an open access article distributed under the Creative CommonsAttribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The concentrations and profiles of paraquat a kind of herbicide were studied in water samples taken from a stream flowing throughfive villages ofMai Chau province the Northern Vietnam during dry and rainy seasons In this study paraquat was found at almostthe sampling sites and showed an average concentration for paraquat to be 3069120583gL and with a maximum of 13408 120583gL Theherbicide concentration tended to be the highest on the dry season because of the least rainfall and also the highest evaporationrate of water in the stream For risk assessment of human health a hazard index (HI) value was calculated for estimating the risktowards the residents HQ in the dry and rainy season is from 00001 to 02448 and from 00001 to 00279 respectively The resultsshowed a minimum risk however there are concerns toward the danger of long-term exposure to the residents from the streamthat could affect their life quality

1 Introduction

Paraquat (111015840-dimethyl-441015840-bipyridyliumdichloride) a kindof a nonselective contact broad-spectrum herbicide hasbeen widely used as a herbicide for many decades [1ndash3]The herbicide is sold in about 130 countries for use on largeand small farms paddies and nonagricultural weed controlGramoxone is the commercial name for paraquat The useof paraquat has been discussed for decades in internationalnational and nongovernmental organizations [4ndash16]

The herbicide under aerobic conditions is rapidly reox-idized by accepting an electron from nicotine adenine din-ucleotide phosphate (NADPH) with resulting formation ofthe superoxide or other oxygen radicals Both the superoxideand the radicals damage cell membranes and cytoplasmfrom NADPH depletion free radical generation and lipidperoxidation or some combination of these factors [17ndash19]It is poorly absorbed through intact skin but penetration isconsiderably increased by damage to the skin which is of par-ticular concern because paraquat itself is a skin irritant [20]

With damage mentioned above using paraquat may posepotential environmental hazards to humans or surroundingecosystems [21 22] Its acute toxicity at oral LD50 rangesfrom 4 to 40mg kgminus1 [23] However up to 35mg kgminus1 canbe absorbed through the skin or respiratory route withoutacute toxic damage Besides irreversible human lung damage[24] recent concern has been raised about an association ofParkinsonrsquos disease to paraquat or a combination of paraquatand fungicide exposures [25] There have been few studieson their appearance persistence and distribution in theenvironment [17 26] and none has been performed in theSoutheastern Asia area However the results that have beenobtained are alarming In water environment paraquat isadsorbed onto particles and sediment with a half-life time tobe between 2 and 820 years depending on sunlight and depthof water and it has been found in both surface waters andgroundwater [27] Paraquat is not easily degraded chemicallyor microbiologically and demonstrates long-term persistencein river waters with more than 80 remaining after 56 daysof incubation [28] In water this compound is completely

HindawiJournal of ChemistryVolume 2018 Article ID 8521012 8 pageshttpsdoiorg10115520188521012

2 Journal of Chemistry

Survey pointBorder communeStream

N

SW E

Scale 1 150000

0 5000 10000(m)

20∘33

20∘33

104∘50

104∘50

20∘44

20∘44

105∘05

105∘05

PiengVo Village

CunPheo Village

XamKhoe Village

MaiHich Village

VanMai Village

Figure 1 Map of the sampling sites in Mai Chau province the Northern Vietnam

ionized and shows an octanol-water partition coefficient(119870ow) of 18 which means that the 644 of paraquat appearsin the octanol phase [28] The toxicity effect of paraquat isfrom low to medium for fish but high for birds [29]

The aim of this study was to evaluate the impact ofparaquat on pollution in water environment For this pur-pose the concentration of this herbicide was studied in astream flowing through five villages of Mai Chau provinceThis area is characteristic of the Northern Vietnam geog-raphy The analytical methodology used is based on theseparation and concentration of the herbicides by solid phaseextraction and determination by means of HPLC with UV[30 31] The risk assessment of human health was estimatedfrom a hazard index (HI) value These results may provideuseful information for establishing paraquat control and giveinitial guidance on the health risk

2 Materials and Methods

21 Taking Sample In this study the samples were collectedfrom a stream flowing through five villages (Cun PheoPieng Ve Mai Hich Xam Khoe and Van Mai) at Mai

Chau province the Northern Vietnam during dry andrainy seasons (Figure 1) Samples of 25 L were taken intopolypropylene containers because paraquat adheres to glass[32 33] Afterward they were filtrated through a Whatman045 120583m membrane filter and stored in a refrigerator at 4∘Cuntil analyzed

22 Analytical Procedure The analytical procedure of par-aquat in the water samples has been described by Ibanezet al [30] Commercial silica Sep-Pak cartridges (Waters)were successively washed with 25mL 05M sulphuric acid5mL distilledwater and 25mL 2 (vv) ammoniumhydrox-ide solution and again with 5mL distilled water Samples(250mL) were passed through the Sep-Pak cartridges [31]Then they were inverted and eluted with 5mL of a mixturecomposed of 2 g tetramethylammonium hydroxide pentahy-drate (TMAOH) and 30 g ammonium sulphate adjusted topH 3 with 5M sulphuric acid and methanol (90 10) A 20 120583Laliquot of the eluted sample was injected onto the HPLCsystem

The HPLC set-up comprised a pump system Alltech 426HPLC a programmable variable-wavelength detector Flexar

Journal of Chemistry 3

UVVIS LC (PerkinElmerUSA)The analytical columnwas aInertsil ODS-3 (GL Sciences Japan) (15 cmtimes 22mm IDfilledwith 3 120583m particle size silica) with a silica guard cartridge(1 cm times 46mm ID 5120583m) was used to prevent damage of theanalytical column

The separation of the selected herbicides was performedby gradient elution The initial mobile-phase compositionwas a 100 solution of 2 g TMAOH with 30 g ammoniumsulphate in 1 L of water and adjusted to pH 3 with 5Msulphuric acid solution It was linearly programmed to mixwith 50 methanol after 15min and hold up during 10minThe flow rate of themobile-phase was 05mLminThe elutedcompounds were monitored with a UV detector set initiallyat 260 nm after 6min for paraquat

The concentrations of paraquat in the final extract werecalculated by interpolating the peak area value in the linearequation obtained by least square adjustment of four pointswhich cover a concentration range of 01ndash10 120583gL

The mean accuracy precision and method detectionlimits (MDLs) were calculated for data acquired from 10replicate analysis of distilled water and from samples of thethree studied areas Samples were spiked at 04 120583gL Themean recovery for paraquat ranged from 85 to 102 Therecovery depends on thewater sample characteristics like pHinorganic salts humic acids and other organic contaminantspresents The precision of the measurements ranged from 35to 127 MDLs ranged from 003 to 009 120583gL depending onthe recovery obtained

23 Dermal Exposure Assessment Based on the informationof the residents using the stream water and the resultsof paraquat concentrations dermal absorbed dose (DAD)value was done after which the hazard quotient (HQ) wascalculated To indicate risk HQ have to be more than one(HQ gt 1) DEA was obtained based on exposure of residentsthrough certain body surfaces for example arms hands legsand feet [34]

DAD =DAevent times EV times ED times EF times SA

BW times AT (1)

where DAD is dermal absorbed dose (mgkg-day) DAeventrepresents the absorbed dose per event (mgcm2-event) SAis surface area available contact (cm2) EV is event frequency(eventsday) EF is exposure frequency (daysyear) and ED isthe exposure duration (years) Additionally BW representedbody weight (kg) and AT is the averaging time (days) wherefor noncarcinogenic effects AT value is equal to the ED times365 daysyear For carcinogenic effects AT is stated as 70years times 365 daysyear As for absorbed dose per event it wascalculated as follows [35]

DAevent = 119870119901 times 119862119908 times 119905event (2)

where the DAevent is the absorbed dose per event (mgcm2-event) 119870119901 is interpreted as the dermal permeability coef-ficient of compound in water (cmhour) and 119862119908 is relatedto chemical concentration in water (mgcm3) while 119905event isthe event duration (hourevent) that was gathered through

10

Dry seasonRainy season

Sampling sites in Mai Chau province

MH

4M

H3

MH

2M

H1

XK5

XK4

XK3

XK2

XK1

PV8

PV7

PV6

PV5

PV4

PV3

PV2

PV1

CP9

CP8

CP7

CP6

CP5

CP4

CP3

CP2

CP10

20406080

100120140

Con

c of

par

aqua

t (

gL)

Mai HichXam KhoePieng Ve villageCun Pheo villagevillagevillage

Figure 2 Concentration of paraquat (120583gL) in four villages (CunPheo Pieng Ve Xam Khoe and Mai Hich) at Mai Chau provincethe Northern Vietnam

questionnaire After DAD value had been obtained it wasused to calculate HQ by dividing the DAD value withreference dose value (RfDABS = 00045mgkgday) [35](see (3)) For the absorption of this chemical compoundthrough different body encounter HQ values were com-bined to form hazard index (HI) with the assumptionthat the effects of different route of entry for paraquatcompound and effects could be additive Thus this formulawas used to estimate the volume possessed by the entryof paraquat compound through several parts of the body[36]

Hazard quotient (HQ) = DADRfDABS (3)

Hazard index (HI) = sumHQArmsHandsLegsFeet (4)

where it was stated that HI value that exceeds one wouldmost probably indicate risk towards the target organ of relatedcompound vice versa

3 Results and Discussion

31 Contamination Characteristic of Paraquat in SurfaceWater The bipyridylium herbicide was found in the studiedareas Concentrations of paraquat in the stream water weregiven in Table 1 with range from 470 to 13408120583gL Medianparaquat concentrations in groundwater in Cun Pheo PiengVe Xam Khoe and Mai Hich were 8114 3495 3051 and1328 120583gL respectively (Table 1) Of the 68 samples analyzedfrom Mai Chau province paraquat was found in 677of the samples However about 426 of these sampleswhich contained paraquat concentrations exceeded Canadadrinking water guideline of 10 120583gL [37] Of the 16 samplestaken in Van Mai village in dry and rainy seasons paraquatwas not detected in 100 of the samples

The results from Table 1 and Figure 2 show that generalpatterns of paraquat accumulation in stream water in MaiChau were Cun Pheo gt Pieng Ve gtMai Hich gt Xam Khoe gt


Table 1 Concentrations of paraquat (120583gL) in the surface watersamples in five villages (Cun Pheo Pieng Ve Xam Khoe Mai Hichand Van Mai) at Mai Chau province in the Northern Vietnam

ParaquatDry season Rainy season

Cun Pheo villageMean 6855 2070SD 4037 1798Min 780 470Max 13408 5574Median 6463 1095119873a 99 99

Pieng Ve villageMean 3495 2111SD 1980 1108Min 530 974Max 5274 4362Median 4098 1846119873 88 58

Xam Khoe villageMean 3051 262SD 538 082Min 2365 172Max 3678 368Median 3009 264119873 55 55

Mai Hich villageMean 1328 45SD 939 -Min 470 45Max 2157 45Median 1343 45119873 44 14

Van Mai villageMean - -SD - -Min - -Max - -Median - -119873 08 08

Drinking water guideline(Canada 1991)

10

aNumber of samples with detectable concentration

Van Mai village It may be explained that amounts of theherbicide used for agriculture by the residents show veryhigh difference between the studied villages The herbicideconcentration tended to be the highest on the dry seasonbecause these are the months with the least rainfall and thehighest evaporation rates

In the comparison with some previous studies concen-trations of paraquat inMai Chau are significantly higher thanthose in some areas reported like in water from marsh of theValencian community Spain 019ndash395120583gL [17] and riversand dams in Saint Lucia range of paraquat is from 05 to10 120583gL [38] and mean concentration of paraquat in surfacewaters in Elechi Creek Niger delta Nigeria is 001120583gL [39]From Warri river basin Niger delta Nigeria ranges from002 to 417 120583gL [40] In the drainage canals of the Kerianpaddy fields Malaysia ranges from 06 to 692120583gL [41](Figure 3)

32 The Information of Residents Using the Stream Water atthe Studied Area Table 2 showed characteristics of the 60residents using the streamwater at the studied areaThe resultindicates that the ages of residents below 40 from 41 to 50from 51 to 60 from 61 to 70 and above 70 are 4833 3667833 5 and 167 respectively Additionally the numberof male residents at 19 persons (3167) is approximately2 times smaller than the female residents of 41 persons(6833) This study has shown that the residents agedbetween 40 and 70 years were predominantly females ratherthan male residents 367 of the residents weighed from51 kg to 60 kg followed by theweight group of 61 kg to 70 kg at30 and 41 kg to 50 kg at 217 those who weigh below 40 kgat 83 and those who are above 70 kg at 33 The peoplewere also asked regarding duration in which they have beenusing paraquat-containing stream water This is to estimatetheir exposure duration with the paraquat It was indicatedthat more than half of the residents involved in this survey(533) were exposed to this compound for approximatelythree years In addition 30 were exposed for two years and83 for one year with only 17 for both four-year and five-year exposure On the other hand 5 of residents indicatedno usage of paraquat at all therefore for the purpose of thisstudy they were considered as to have no direct exposure tothe compound

33 Dermal Exposure Assessment Analysis It can be seenfrom Figure 4 that the HI values for the residents living fivestudied villages decreased in the order Cun Pheo gt Pieng VeMai Hich gt Xam Khoe gt Van Mai village The HQ values forthe residents aremuch smaller than 1 (whereHQ gt 1 indicatesat risk [36]) therefore the risk of paraquat to the health ofthe residents living in studied areas is insignificant (Table 3and Figure 4) HQ in the dry season is from 00001 to 02448and mean is 0013 HQ in the rainy season is from 00001 to00279 and mean is 00052 The HQ mean value of paraquatin the dry season is approximately 9 times higher than that inthe rainy season

4 Conclusions

The studied areas showed the presence of paraquat Paraquatwas detected in a number of sites at levels sometimes consid-erably above of 10 120583gL value established by Canada drinkingwater guideline The average concentration of paraquat was3069 120583gL and these values tended to be the highest during


Valencian Spain [17]

Saint Lucia [38]

Niger delta Nigeria [39]


Kerian Malaysia [41]

Mai Hich Vietnam (this study)

Xam Khoe Vietnam (this study)

Pieng Ve Vietnam (this study)

Cun Pheo Vietnam (this study)





Dry season

Rainy season

10minus2

10minus1

100

101

102

103

10minus3

Paraquat concentration (gL)

Figure 3 Paraquat concentrations (120583gL) in surface water in paraquat-contaminated areas Bar and line indicate range and medianrespectively

1 2 3 4 5 6 7 8 9 10 11 12 13 14Residents in Cun Pheo village





1 2 3 4 5 6 7 8 9 10 11 12 13Residents in Pieng Ve village

1 2 3 4 5 6 7 8 9 10 11 12Residents in Xam Khoe village

1 2 3 4 5 6 7 8 9 10 11Residents in Mai Hich village

000

010

020

030

040

050

Haz

ard

inde

x (H

I)

012

010

007

005

002

000

000

002

005

007

010

012

Haz

ard

inde

x (H

I)

012

010

007

005

002

000

Figure 4 Hazard index of residents living in Mai Chau in dry and rainy seasons


Table 2 Characteristics of residents living in the studied areas in Mai Chau province

Characteristics Number (119899 = 60) Percentage ()SexMale 19 3167Female 41 6833Age (years)lt40 29 483341ndash50 22 366751ndash60 5 83361ndash70 3 500gt70 1 167Weight (kg)lt40 5 83041ndash50 13 217051ndash60 22 367061ndash70 18 3000gt70 2 330Hours (used the stream water) per day05 20 33301 37 61702 1 1703 2 330Days (used the stream water) per week3 1 1704 7 11705 3 5006 17 28307 32 5330Exposure to paraquat (year(s))None 3 5001 5 8302 18 30003 32 53304 1 1705 1 170

the dry season These are the months with the least rainfalland highest temperatures The results obtained show theubiquitous presence of paraquat in the studied villages atthe Mai Chau environment where their accumulation instreams gives rise to situations that could affect the foodchain and human health The risk assessment of humanhealth showed the insignificant effect of paraquat (HQ lt1) However the use of paraquat for agriculture at thisarea should be controlled and adjusted to real needs Thepresence of these herbicides in the environment shouldbe monitored in order to establish the real impact on theflora and fauna Further studies are needed to evaluate thepotential health effects of paraquat from stream Further-more neurological tests should be conducted to examine the

prevalence of chronic paraquat poisoning symptoms to bestudied for the residents in Mai Chau province the NorthernVietnam

Conflicts of Interest

The authors declare that they have no conflicts of interest

Acknowledgments

This study was supported by the VAST 070216-17 projectand the authors would like to express special thanks to thePresident andDirectorate of theVietnamAcademyof Scienceand Technology (VAST) for their kind support


Table 3 The risk assessment values of the residents using stream water in the studied areas in the dry and rainy seasons

Dry season Rainy seasonHQArm HQHand HQLeg HQFeet HI HQArm HQHand HQLeg HQFeet HI

Cun Pheo villageMean 00065 00342 00121 00685 01209 00127 00070 - - 00197SD 00068 00376 00136 00751 01330 00086 00099 - - 00158Min 00008 00002 00001 00004 00008 00000 00000 - - 00000Max 00229 01224 00459 02448 04360 00279 00262 - - 00465Median 00029 00170 00058 00339 00596 00123 00017 - - 00135119873a 14Pieng Ve villageMean 00016 00088 00032 00177 00313 00043 00033 - - 00076SD 00010 00052 00019 00104 00184 00062 00046 - - 00108Min 00001 00004 00002 00008 00016 00000 00000 - - 00000Max 00031 00157 00062 00313 00558 00170 00123 - - 00293Median 00015 00092 00031 00184 00321 00002 00004 - - 00006119873 13Xam Khoe villageMean 00022 00107 00044 00214 00387 00007 00001 - - 00007SD 00012 00063 00024 00125 00221 00004 00001 - - 00004Min 00009 00036 00018 00073 00137 00002 00000 - - 00002Max 00045 00268 00089 00536 00938 00013 00002 - - 00015Median 00020 00087 00039 00174 00316 00007 00001 - - 00008119873 12Mai Hich villageMean 00009 00044 00018 00088 00159 00001 00000 - - 00001SD 00005 00029 00011 00059 00103 00002 00000 - - 00002Min 00004 00021 00008 00042 00075 00000 00000 - - 00000Max 00020 00117 00039 00235 00411 00004 00001 - - 00005Median 00008 00030 00017 00060 00110 00000 00000 - - 00001119873 11Van Mai villageMean - - - - - - - - - -SD - - - - - - - - - -Min - - - - - - - - - -Max - - - - - - - - - -Median - - - - - - - - - -119873 10aNumber of residents with using the stream water at studied sites

References

[1] WHO ldquoInternational Programme on Chemical Safetyrdquo inProceedings of the Paraquat Health and Safety Guide GenevaSwitzerland 1991

[2] C Tomlin The Pesticide Manual The British Crop ProtectionCouncil Hampshire UK 13th edition 2003

[3] Instituto Nacional de Estadıstica Indicadores de ConsumoContabilidad Regional de Espana Madrid Espana 1996

[4] ldquoClinical aspects of paraquat poisoningrdquo in Proceedings of anInternational Meeting held on October 7 1975 K Fletcher EdManchester UK 1977

[5] P J Levin L J Klaff A G Rose and A D Ferguson ldquoPul-monary effects of contact exposure to paraquat A clinical andexperimental studyrdquoThorax vol 34 no 2 pp 150ndash160 1979

[6] WHO ldquoEnvironmental Health Criteria 39rdquo in Proceedings of theInternational Program on Chemical Safety (IPCS) Paraquat anddiquat Geneva Switzerland 1984

[7] S A Malaysia ldquoParaquat another scourge from the merchantsof deathrdquo Journal of Pesticide Reform pp 13ndash15 1986

[8] L J Onyon and G N Volans ldquoThe epidemiology and preven-tion of paraquat poisoningrdquoHumanampExperimental Toxicologyvol 6 no 1 pp 19ndash29 1987

[9] A Vale and G Volans ldquoEditorial The Second EuropeanSymposium on Paraquat Poisoning 27th January 1986 Guyrsquos


Hospital Londonrdquo Human amp Experimental Toxicology vol 6no 1 pp 3ndash6 1987

[10] J G Smith ldquoParaquat poisoning by skin absorption A reviewrdquoHuman amp Experimental Toxicology vol 7 no 1 pp 15ndash19 1988

[11] B Dinham ldquoICI Limited Paraquat production starting thechain A report for Greenpeace Internationalrdquo London UK1989

[12] W Barclay Review of the pesticide paraquat for submission to theWorld Bank Pesticide Advisory panel Greenpeace WashingtonDC USA 1989

[13] B Dinham The Pesticide Hazard Zed Books London UK Aglobal health and environmental audit edition 1993

[14] C Bismuth and A H Hall Eds Paraquat poisoning mecha-nisms prevention and treatment Marcel Dekker New York NYUSA 1995

[15] C Wesseling C Hogstedt A Picado and L Johansson ldquoUnin-tentional fatal paraquat poisonings among agricultural workersin costa rica Report of 15 casesrdquo American Journal of IndustrialMedicine vol 32 no 5 pp 433ndash441 1997

[16] E L Foro For the prohibition of paraquat (Por la prohibicion delparaquat en Costa Rica) Limon Costa Rica Foro Emaus CostaRica Foro Emaus 2001

[17] M Fernandez M Ibanez Y Pico and J Manes ldquoSpatialand temporal trends of paraquat diquat and difenzoquatcontamination inwater frommarsh areas of theValencian com-munity (Spain)rdquo Archives of Environmental Contamination andToxicology vol 35 no 3 pp 377ndash384 1998

[18] J S Bus and J E Gibson ldquoParaquat model for oxidant-initiatedtoxicityrdquo Environmental Health Perspectives vol 55 pp 37ndash461984

[19] Y Quan B S Todd J T Greenamyre and W M GaryldquoParaquat neurotoxicity is distinct from that of MPTP androtenonerdquo Toxicological Sciences vol 88 pp 193ndash201 2005

[20] A Tabak U Taitelman and E Hoffer ldquoPercutaneous perme-ability to paraqut In vitro experiments with human skinrdquoCutaneous andOcular Toxicology vol 9 no 4 pp 301ndash311 1990

[21] A M Tsatsakis K Perakis and E Koumantakis ldquoExperiencewith acute paraquat poisoning in CreterdquoVeterinary andHumanToxicology vol 38 no 2 pp 113ndash117 1996

[22] L C De ldquoVademecum de productos fitosanitarios y nutri-cionalesrdquo Agrotecnicas SL 1997

[23] L A Summers The Bipyridinium Herbicides Academic PressLondon UK 1980

[24] WorldHealthOrganization Paraquat andDiquat Environmen-tal Health Criteria WHO Geneva Switzerland 1984

[25] T Rickey Combination of two widely used pesticides linked toParkinsons disease URL http 2001 httpwwwurmcrochestereduprNewsparkhtml (accessed

[26] K A Langeland A M Fox F B Laroche et al ldquoDiquatDistribution in Water after Application to Submersed WeedsrdquoJAWRA Journal of the American Water Resources Associationvol 30 no 1 pp 93ndash97 1994

[27] M Watts and Paraquat Pesticide Action Network Asia andPacific 2011

[28] Y-SWang J-H Yen Y-N Hsieh and Y-L Chen ldquoDissipationof 24-D glyphosate and paraquat in river waterrdquo Water Air ampSoil Pollution vol 72 no 1-4 pp 1ndash7 1994

[29] S A Briggs Ed Basic Guide to Pesticides Their Characteristicsand Hazards Rachel Carson Council 1992

[30] M Ibanez Y Pico and J Manes ldquoInfluence of organic matterand surfactants on solid-phase extraction of diquat paraquatand difenzoquat from watersrdquo Journal of Chromatography Avol 727 no 2 pp 245ndash252 1996

[31] M Ibanez Y Pico and J Manes ldquoImproving the solid-phaseextraction of ldquoquatrdquo pesticides from water samples Removal ofinterferencesrdquo Journal of Chromatography A vol 823 no 1-2pp 137ndash146 1998

[32] V A Simon ldquoHPLC assay with confirmation of low levels ofparaquat and diquat in well waterrdquo LC-GC vol 5 no 10 pp899ndash903 1987

[33] V A Simon and A Taylor ldquoHigh-sensitivity high-performanceliquid chromatographic analysis of diquat and paraquat withconfirmationrdquo Journal of Chromatography A vol 479 no C pp153ndash158 1989

[34] United States Environmental Protection Agency Exposure factorshandbook US Environmental Protection Agency EPA 2011

[35] United States Environmental Protection Agency in EPAOSWER Risk Assessment ldquoSupplemental Guidance for DermalRisk Assessmentrdquo Part E of Risk Assessment Guidance forSuperfund vol 1 Human Health Evaluation Manual 2004

[36] U M Pan and W Siriwong ldquoRisk assessment for dermal expo-sure of organophosphate pesticide in rice growing residentsat Rangsit Agricultural Area Pathumthani Province CentralThailandrdquo Journal of Health Research vol 24 pp 141ndash148 2010

[37] ldquoGuidelines for canadian drinking water qualityrdquo GuidelineTechnical Document Paraquat Health Canada Canada NorthAmerica 1991

[38] ldquoImpact and amelioration of sediment and agro-chemical pol-lution in caribbean coastal watersrdquo DFID NRSP Project R7668Report 4 2002

[39] F Upadhi and O A F Wokoma ldquoExamination of SomePesticide Residues in Surface Water Sediment and Fish Tissueof Elechi Creek Niger Delta Nigeria Researchrdquo Journal ofEnvironmental and Earth Sciences vol 4 pp 939ndash944 2012

[40] T O Ikpesu ldquoAssessment of occurrence and concentrations ofparaquat dichloride in water sediments and fish from WarriRiver Basin Niger Delta Nigeriardquo Environmental Science andPollution Research vol 22 no 11 pp 8517ndash8525 2015

[41] B S Ismail M Sameni and M Halimah ldquoEvaluation ofherbicide pollution in the kerian ricefields of Perak MalaysiardquoWorld Applied Sciences Journal vol 15 no 1 pp 05ndash13 2011

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Submit your manuscripts atwwwhindawicom


Survey pointBorder communeStream

N

SW E

Scale 1 150000

0 5000 10000(m)

20∘33

20∘33

104∘50

104∘50

20∘44

20∘44

105∘05

105∘05

PiengVo Village

CunPheo Village

XamKhoe Village

MaiHich Village

VanMai Village

Figure 1 Map of the sampling sites in Mai Chau province the Northern Vietnam

ionized and shows an octanol-water partition coefficient(119870ow) of 18 which means that the 644 of paraquat appearsin the octanol phase [28] The toxicity effect of paraquat isfrom low to medium for fish but high for birds [29]

The aim of this study was to evaluate the impact ofparaquat on pollution in water environment For this pur-pose the concentration of this herbicide was studied in astream flowing through five villages of Mai Chau provinceThis area is characteristic of the Northern Vietnam geog-raphy The analytical methodology used is based on theseparation and concentration of the herbicides by solid phaseextraction and determination by means of HPLC with UV[30 31] The risk assessment of human health was estimatedfrom a hazard index (HI) value These results may provideuseful information for establishing paraquat control and giveinitial guidance on the health risk

2 Materials and Methods

21 Taking Sample In this study the samples were collectedfrom a stream flowing through five villages (Cun PheoPieng Ve Mai Hich Xam Khoe and Van Mai) at Mai

Chau province the Northern Vietnam during dry andrainy seasons (Figure 1) Samples of 25 L were taken intopolypropylene containers because paraquat adheres to glass[32 33] Afterward they were filtrated through a Whatman045 120583m membrane filter and stored in a refrigerator at 4∘Cuntil analyzed

22 Analytical Procedure The analytical procedure of par-aquat in the water samples has been described by Ibanezet al [30] Commercial silica Sep-Pak cartridges (Waters)were successively washed with 25mL 05M sulphuric acid5mL distilledwater and 25mL 2 (vv) ammoniumhydrox-ide solution and again with 5mL distilled water Samples(250mL) were passed through the Sep-Pak cartridges [31]Then they were inverted and eluted with 5mL of a mixturecomposed of 2 g tetramethylammonium hydroxide pentahy-drate (TMAOH) and 30 g ammonium sulphate adjusted topH 3 with 5M sulphuric acid and methanol (90 10) A 20 120583Laliquot of the eluted sample was injected onto the HPLCsystem

The HPLC set-up comprised a pump system Alltech 426HPLC a programmable variable-wavelength detector Flexar








BW times AT (1)




10



MH

4M

H3

MH

2M

H1

XK5

XK4

XK3

XK2

XK1

PV8

PV7

PV6

PV5

PV4

PV3

PV2

PV1

CP9

CP8

CP7

CP6

CP5

CP4

CP3

CP2

CP10

20406080

100120140

Con

c of

par

aqua

t (

gL)



















10






4 Conclusions




Saint Lucia [38]












Dry season

Rainy season

10minus2

10minus1

100

101

102

103

10minus3











000

010

020

030

040

050

Haz

ard

inde

x (H

I)

012

010

007

005

002

000

000

002

005

007

010

012

Haz

ard

inde

x (H

I)

012

010

007

005

002

000









Acknowledgments






References

















































Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls











BW times AT (1)




10



MH

4M

H3

MH

2M

H1

XK5

XK4

XK3

XK2

XK1

PV8

PV7

PV6

PV5

PV4

PV3

PV2

PV1

CP9

CP8

CP7

CP6

CP5

CP4

CP3

CP2

CP10

20406080

100120140

Con

c of

par

aqua

t (

gL)



















10






4 Conclusions




Saint Lucia [38]












Dry season

Rainy season

10minus2

10minus1

100

101

102

103

10minus3











000

010

020

030

040

050

Haz

ard

inde

x (H

I)

012

010

007

005

002

000

000

002

005

007

010

012

Haz

ard

inde

x (H

I)

012

010

007

005

002

000









Acknowledgments






References

















































Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls













10






4 Conclusions




Saint Lucia [38]












Dry season

Rainy season

10minus2

10minus1

100

101

102

103

10minus3











000

010

020

030

040

050

Haz

ard

inde

x (H

I)

012

010

007

005

002

000

000

002

005

007

010

012

Haz

ard

inde

x (H

I)

012

010

007

005

002

000









Acknowledgments






References

















































Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls






Saint Lucia [38]












Dry season

Rainy season

10minus2

10minus1

100

101

102

103

10minus3











000

010

020

030

040

050

Haz

ard

inde

x (H

I)

012

010

007

005

002

000

000

002

005

007

010

012

Haz

ard

inde

x (H

I)

012

010

007

005

002

000









Acknowledgments






References

















































Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls











Acknowledgments






References

















































Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls








References

















































Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls











































Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls




paraquat in surface water of some streams in mai chau...

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