Hydrocarbon emissions and health risks from cookstoves in developing countries

Abstract

The nonmethane hydrocarbon emissions from several types of cookstoves commonly used in developing countries were measured in a pilot study conducted in Manila, the Philippines. Four types of fuel, i.e., wood, charcoal, kerosene, and liquefied petroleum gas (LPG), were tested. Because kerosene was burned in three different types of stoves, there were six fuel/stove combinations tested. Fifty-nine nonmethane hydrocarbons were identified frequently in emissions of these cookstoves, with emission ratios to CO2 up to 5.3 x 10-3. The emissions were quantitated with emission factors on both a mass basis (emissions/kg fuel) and a task basis (emissions/cooking task). On a task basis, combustion of biomass fuels (wood and charcoal) generally produced higher emission factors than combustion of fossil fuels (kerosene and LPG). One type of kerosene stove (wick stove), however, still generated the greatest emissions of some individual and classes of hydrocarbons, indicating that emissions were dependent on not only fuel types but also combustion devices. Some hydrocarbons, e.g., benzene, 1,3-butadiene, styrene, and xylenes, were of concern because of their carcinogenic properties. The lifetime risk from exposures to these compounds emitted from cookstoves was tentatively estimated by using a simple exposure model and published cancer potencies. Among the six fuel/stove combinations, wood stoves generated the highest cancer risk and LPG generated the least. Compared to the cancer risks of benzene and 1,3-butadiene, those of styrene and xylenes were negligible. The estimated cancer risk of benzene or that of styrene from use of a biomass cookstove exceeded published risk estimates from all sources of airborne benzene or styrene (excluding active tobacco smoking) in the United States.