Impacts of cooking system on indoor air environment: a case study on a Bangladeshi village

Energy is needed to meet the subsistence requirement as well as to meet the demand for economic growth and development. As like many other third world countries still more than half of the total consumed energy comes from the traditional fuels in Bangladesh. This is causing rapid deforestation and consequently a change in the eco-systems leading to erosion and change in the climatic pattern. Extreme use of raw (low quality) biomass traditional cook stoves causes significant impacts on indoor air environment and as well on human health. In the study, an assessment of the cooking energy usage pattern, its potential impacts on indoor air environment and human health in a village named Deyara in Khulna district has been performed. The socio-economic status of the villagers and cooking energy usage pattern were evaluated by a questionnaire survey. In the study village Deyara, about 74% of the total households rely on biomass fuel, where the mostly used biomass is trees and its residues (46%), next the crop wastes (39%) and lastly the cow dung (15%). Emissions of different types of air pollutants and greenhouse gases from the burning of biomass cooking fuels the study village are estimated. In the study area the estimated annual emission of CO/sub 2/ is 45.5 tons which about 94% of the total emission, where CO is 4.5%, PM is 1 % and about 0.5% emission is of SO/sub x/, NO/sub x/, N/sub 2/O. In the study area the concentrations of air pollutants in the kitchen environment were estimated using an indoor air quality model. The model results show that the concentration around the household areas is not at tolerable level and due to only 1 hour biomass burning this concentration is 323 mg/m/sup 3/ for CO, 50.6 mg/m/sup 3/ for PM, 15 mg/m/sup 3/ for NO/sub 2/ and 9.6 mg/m/sup 3/ for SO/sub 2/. Not only this, from the combustion of biomass cooking fuels this concentrations of different carcinogens are also at high levels. For 1 hour burning of biomass fuel this concentration is 1624.8 micro g/m/sup 3/ for benzene, 812.4 micro g/m/sup 3/ for xylene, 333.9 micro g/m/sup 3/ for 1,3-butadeine, 243.7 micro g/m /sup 3/ for syrene. From the study is found that the daily exposure, which was calculated, is higher to chief-cook than the non-cook both for PM and CO. For this high exposure the people of the study area, mainly the women and their children face some severe health problems. About 30% of the exposed people suffer from dizziness while 60% feel severe headache. The eye irritation is another major problem they can feel for the duration of cooking. The problems that can be prominent are chest pain, several respiratory problems, asthma, bronchitis, premature mortality, etc. The lifetime risk of a typical woman from exposures to pollutants emitted by cook stoves were estimated. In the study area the changes in mortality for the cooks is 1.829 x 10/sup -03/ and for non-cooks is 3.554 x 10/sup -04/ due to use biomass cooking fuel. These estimates illustrate that doses and concentrations experienced by women and children in homes burning biomass fuels are significantly high. (author)