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Assessment of Effectiveness of ICS in Reducing Indoor Air

Pollution and Improving Health in Nepal1

B. Tuladhara,*, I. Gurunga, B. Shresthaa, A. Singha, K. Karkia, A. Pillarisetti b,

K. BajracharyacaEnvironment and Public Health Organization (ENPHO), Kathmandu, Nepal

bFull Bright ScholarcAlternative Energy Promotion Center/Energy Sector Assistance Programme (ESAP), Ministry of Environment,

Science and Technology

Abstract

A popular technology to reduce indoor air pollution (IAP) in rural homes of Nepal is the mud brick improved cook stoves (ICS) which isbeing promoted by the National Biomass Energy Support Programme of Energy Sector Assistance Programme (ESAP) / Alternative Energy

Promotion Centre (AEPC), as well as other agencies and so far more than 230,000 ICS have been installed in the country. A research

conducted by Environment and Public Health Organization (ENPHO) for the Biomass Energy Programme of AEPC/ESAP has found that

the average concentration of PM2.5 and CO in houses that use traditional cook stoves is very high but the mud brick ICS was able to reducethe PM2.5 by 65.7% and CO by 62.3% after three months and 63.2% and 60.0% respectively after one year of installation of the ICS. The

study, which was conducted in three districts (Dolakha, Ilam and Dang), followed the Before-After design; hence both pollutionmeasurements and questionnaires survey were conducted twice for each of the 36 participating households: first before the installation of

ICS or with traditional cook stoves (TCS) and the second after the installation of ICS. A cross-sectional study done at the same time in 72households in Kavre district also had similar results. The average PM 2.5 concentration in households with ICS was 66.4% less than the

households with traditional stoves. Similarly the concentration of CO was 62.3 % less in households with ICS. The reduced pollution level

also results in major health benefits. However as the pollution levels are still higher than WHO guideline values even after installation ofICS, there is a need for more improvement in areas such as ventilation and kitchen management.

Keywords: indoor air pollution, ICS, PM2.5, CO, health

1. INTRODUCTION

With more than 80 percent of the population

depending on solid biomass fuel, such as wood,dung and agricultural residues, for cooking, indoor

air pollution (IAP) is a major problem in Nepal.

WHO estimates that 2.7 percent of Nepals national

burden of disease is attributed to solid fuel use and

this causes 7500 deaths per year (WHO, 2007). In

order address this problem, different government

and non-government organizations, as well as

private companies and international agencies have

initiated various programmes and introduced a

variety of technologies to reduce IAP in Nepal. One

of the most simple and popular technologies to

reduce IAP in rural homes in Nepal has been the

improved cook stoves (ICS). The mud brick ICS isbeing promoted by the Energy Sector Assistance

Programme (ESAP) of the Alternative Energy

Promotion Centre (AEPC), as well as other

agencies. So far more than 230,000 such stoves have

been installed in the country and AEPC/ESAP plans

to install 500,000 stoves in its second phase (2007-

2012).

Realizing the need for effective monitoring and

evaluation, AEPC/ESAP assigned Environment and

Public Health Organization (ENPHO) to conduct an

assessment of the effectiveness of ICS in reducing

indoor air pollution and improving the health. The

study had two major activities: (i) measurement of

24-hr mean concentrations of two principal indoor

air parameters particulate matter of size less than2.5 micron (PM2.5) and carbon monoxide (CO); and

(ii) questionnaire survey and observation for both

indoor air pollution and health impact assessment.

2. STUDY DESIGN

The design for this study was developed by ENPHO

together with AEPC/ESAP in consultation with

experts from the Centre for Entrepreneurship in

International Health Development (CEIHD),

University of California, Berkeley in order to ensure

that it was technically sound and comparable to

other international studies of similar nature. It isbased on the international best practices, a review of

recent literature on study design for similar studies

and optimum utilization of available resources in

terms of time, funding and equipment The study

followed the Before-After design; hence both

pollution measurement and questionnaires survey

were conducted three times for each household: first

before the installation of ICS or with traditional

cook stoves (TCS), second: three months after the

installation of ICS two pot-hole mud brick stove to

see immediate impacts and the third: one year after

installation of ICS to assess long term impacts.

1 Paper presented at International Conference on Renewable Energy Technology for Sustainable Development,

Kathmandu, Nepal, 2009


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Particulate matter less than 2.5 microns (PM2.5) and

carbon monoxide (CO) were selected as the key

pollution parameters for this study as these

parameters are generally regarded by experts,

including the World Health Organization and the

University of California Berkeley, as the two bestindicators of IAP. The concentration of PM2.5 wasmeasured using UCB particle monitors while CO

concentration was measured using HOBO CO

loggers. Both these equipment were purchased new

from CEIHD and calibrated at the Indoor Air

Pollution Laboratory of University of California

Berkeley. Both of these equipments contain data

loggers, which store the minute-by-minute data over

the entire measurement period. After monitoring,

these data are then downloaded into a personal

computer and analyzed.In both Before and Afterphases of IAP monitoring, the sampling was done

for 24 hours for both PM2.5 and CO followingstandard protocols developed by CEIHD so that the

data can be compared with WHO Guideline Values.For the questionnaire survey, two different sets of

questionnaires one for IAP and the other for health

impact assessment were administered in both phases

of study. The questionnaires were designed based on

international guidelines and experiences of Nepalese

environmental health experts.

In order to get representative samples from

households across Nepal, the study was done in

three different districts representing differentecological zones and cultural settings. Data for

before installation of ICS was collected from 47

households in three different districts Boch VDC

in Dolakha, representing high hills of Nepal, Mabu

VDC in Ilam representing mid-hills and Laxmipur

VDC in Dang in the plains. The data for three

months after installation of the ICS was collected

from 36 of the same households, while the one year

data was collected from 34 of the same households.

The field studies were done between October 2007

and February 2009.

Parallel to this study, ENPHO also conducted a

cross-section study in Kavre District in the mid hills

in 36 households with ICS and 36 households

without ICS using the same equipment in 2008.

The required sample size for both the studies was

determined based on statistical rules and sampling

techniques designed by the CEIHD for the

Household Energy and Health Project. According to

Edwards et al (2007), the sample size required to

detect a statistically significant difference in the

mean indoor air pollution levels before and after the

installation of the ICS depends on the percentdifference in those means and in the variability in

the differences in those means (Before After).

The coefficient of variation (COV) is an indicator of

the variability in measurements, and reflects the

range of air pollution concentrations in different

homes in comparison to the mean concentration in

the same homes. It is equal to the standard deviation

(SD) divided by the mean. Based on a conservative

COV of 1.0 and a detectable difference of 50%, itwas decided that at least 31 households would be

required to be sampled both before and after the

installation of ICS.

3. KEY FINDINGS

Some of the major findings of the study are as

follows:

The average 24-hr mean PM2.5 concentration

was 2.127 mg/m3 in before phase (kitchens with

TCS) and 0.728 mg/m3 the after three months

and 0.762 mg/m3 after one year of switching to

ICS. The average 24-hr mean CO concentration

was 22.174 ppm with TCS and 8.349 ppm with

the ICS after three months and 8.621 ppm after

one year. The average percent change of the

IAP concentration between the TCS and ICS

were therefore 65.7% and 63.2% after three

months and after one year for PM2.5 and 62.3%

and 60.0% after three months and after one year

for CO. The data shows that the pollution levels

in houses that use TCS are very high and the

ICS that is promoted in Nepal is quite

successful in reducing IAP. However the fact

that the pollution levels are still higher than

WHO guideline values even after installation of

ICS shows that there is a need for more

improvement in areas such as ventilation and

kitchen management. The WHO guideline

values for ambient air quality for PM10 and

PM2.5 is presented in Table 1. WHO does not

have specific guideline values for indoor air

quality but the ambient air quality guidelines is

also applicable to all non-occupational

environments, including indoors.

Table 1: WHO Air Quality Guidelines

Annual 24 hr. AveragePM10 PM 2.5 PM10 PM2.5

Interim

Target 1

70 35 150 75

Interim

Target 2

50 25 100 50

Interim

Target 3

30 15 75 37.5

Guideline

Value

20 10 50 25

Source: WHO, 2005

By district, the highest and lowest 24-hr

average mean PM2.5 and CO concentrationswere measured in Dolakha and Ilam


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respectively in both before and after

measurements. In Dolakha, the measured mean

concentrations of PM2.5 were 3.374mg/m3 with

TCS and 1.429mg/m3 with the ICS and for CO

these were 38.557ppm with TCS and

17.172ppm with ICS. In Ilam, the mean PM2.5

and CO were respectively 0.889mg/m3

and8.660ppm with the TCS; and 0.728mg/m3 and

3.337ppm with the ICS. The large difference in

pollution levels in the two districts both before

and after the installation of the ICS shows that

other factors, besides the stove design, such as

ventilation and cooking habits are also very

important in determining IAP levels.

Table 2: Pollution levels before and after

installation of ICS

Parameter

Mean Value(mg/m3)

Avg %reduction

after 1 yr

Before 3 mo 1 yr.

Dolkha

PM2.5 3.374 1.429 1.312 59.3

CO 38.657 17.217 15.210 58.3

Ilam

PM2.5 0.889 0.308 0.368 51.6

CO 8.660 3.337 3.854 55.5

Dang

PM2.5 2.653 0.749 0.818 70.6

CO 26.269 8.320 8.571 67.4Mean

PM2.5 2.127 0.728 0.762 63.2

CO 22.174 8.349 8.621 60.0

The percent reduction in pollution level is also

significantly different in the different

households. While a few houses it was found

that the level of PM2.5 decreased by over 90

percent, in one house the PM2.5 concentration

actually increased. This again shows that the

while the potential for pollution reduction by

the mud brick ICS is very high, there are

several other factors which need to beconsidered. These include operation and

maintenance of the stoves, ventilation and

kitchen management.

%reductioninPM2.5in

individualHH

100

90

80

70

60

50

40

30

20

10

0

-10

Figure 1: Absolute differences of PM2.5concentrations in each household (each bar

represents a household)

%reductioninCOinindividualhousehold

100

75

50

25

0

-25

-50

Figure 2: Absolute differences of CO concentrations

in each household (each bar represents a household)

The correlation between the concentration

levels of 24-hr CO and PM2.5 measurements

both in TCS and ICS combined together (N=72;

Pearsons Correlations Coefficient = 0.841) was

also found highly significant.

According to the main cook, remarkable

improvements in the health condition of boththe women and young children were observed

following the installation of ICS. Major health

outcomes included upper respiratory infections

such as cough, phlegm, influenza,

whistling/wheezing of the chest, headaches and

eye irritation; the occurrence of these health

outcomes were substantially reduced after ICS

installation. Reported coughing events

decreased from 55.6% to 16.7% after ICS

installation in adults. In children, a similar

change was reported from 96.2% to 46.2% after

installation. However, as there was only a three

month gap between the installation of the ICS


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and second phase of the assessment, the actual

health impacts of ICS may not be very clear.

The concentration levels of IAP were found to

be affected by a number of factors. Major

among them included ventilation condition, fuel

types and condition, users behavior,geographical and climatic condition, and to

some extent, installation and use of the ICS.

Thus 69% of the households were reported

occasional problem of smoke coming back into

the kitchen.

The results of the cross-sectional study was

very similar to the result from the before &

after study. The cross sectional study done in 72

households found that the average PM2.5concentration in households with ICS was

66.4% less than the households with traditional

stoves. Similarly the concentration of CO was

62.3 % less in households with ICS.

The findings of this study are similar to the

findings of other similar studies in other countries

including Two recent studies were performed

following a similar 'before and after' study design

and using identical equipment in regions of India.

Outside of Pune, India, the Appropriate Rural

Technology Insitute (ARTI) evaluated indoor air

pollution levels in 110 homes between August 2004

and December 2005. Two types of improved stoves

were installed in this region the Laxmi stove andthe Bhagyalaxmi stove. One year after the

installation of these stoves, ARTI noted a 24%

reduction in mean PM2.5 concentrations for the

Laxmi stove and a 49% reduction for the

Bhagyalaxmi stove. CO concentrations were

similarly reduced by 39% in Laxmi and 38% in

Bhagyalaxmi stoves (Dutta et. al, 2007). In the

Bundelkhand region of India, Development

Alternatives (DA) evaluated improvements in IAQ

after ICS installation in 60 households. One year

after installation of the stoves, 48 hour CO

concentrations were reduced by 70% and 48-hour

PM concentrations were reduced by 44%(Chengappa, et. al., 2007).4. CONCLUSIONS

Overall, the study has found very high levels of

indoor air pollution from burning of biomass fuels,

particularly in houses with poor ventilation. This

can be a major health hazard, particularly for

women and children. However, the study has also

clearly shown that the simple, low-cost and locally

built mud brick ICS can reduce the pollution levels

as indicated by concentration of PM2.5 and CO bymore than 60 percent. The study also indicates that

the ICS also results in significant health benefits as

well as other benefits such as reduced firewood

consumption, cleaner kitchens, and reduced time for

cooking. Overall the ICS users are satisfied with

their new stoves and feel that reduced smoke,

improved health and reduced firewood consumption

are the main benefits of the stoves. However, thereis a need for more awareness programmes for

scaling up ICS throughout the country. The findings

of this study can be used as a tool for motivating

people to install ICS. The study also shows that

proper operation and maintenance of the ICS is

essential for fully achieving its desired results and

other aspects such as improved ventilation and

kitchen management are also equally important.

AEPC/ESAP and ENPHO is currently conducting a

follow up monitoring the same households one year

after installation of the ICS. This will provide more

valuable information on operation and maintenanceof the ICS and its performance over a long period.

ACKNOWLEDGEMENT

The authors are grateful to the support provide by

AEPC/ESAP for conducting this study and the

technical support provided by CEIHD and

Partnership for Clean Indoor Air (PCIA) in

designing the study and procuring the necessary

equipment. In the field, the Regional Renewable

Energy Service Centers of AEPC/ESAP particularly

Centre for Rural Technology (CRT), Namsaling

Community Development Center (NCDC) andResource Management and Rural Empowerment

Center (REMREC), and their staff were very

helpful.

__________________* Corresponding Author: Tel: +977-1-4468641, E-mail:[email protected]

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