Inhalation Risk Assessment of PAH Exposure Due to Combustion Aerosols Generated from Household Fuels

ABSTRACT

The typical mixtures of polycyclic aromatic hydrocarbons are established as lung carcinogens, but their exposure and associated risk from different household fuels are less known. Five commonly used household fuels namely firewood, coal, dung cake, kerosene, and liquefied petroleum gas (LPG) were tested for their size-fractionated polycyclic aromatic hydrocarbon (PAHs) emission. A total of sixteen PAHs were analyzed in size fractionated combustion aerosols using HPLC-UV technique. Single box modeling approach is applied to estimate time average B[a]P_eq concentration of PAHs in indoor air during cooking time. Incremental lifetime cancer risk (ILCR) of PAH exposure during cooking time was calculated, which was found to have a positively skewed distribution for all types of fuels combustion. The uncertainty and variability of the predicted exposure risk were evaluated using Monte Carlo simulation. The 50th percentile of risk due to exposure of PAHs emissions during household use of fuels were found to be 6.25 × 10^–5, 2.99 × 10^–5, 9.11 × 10^–5, 1.14 × 10^–5, and 3.84 × 10^–6 for firewood, coal, dung cake, kerosene and LPG stove, respectively. The 50^th percentile value of risk indicates the hazard associated with solid biomass combustion is higher than non-solid fuels; the risk associated with LPG stove use is found to be one order of magnitude less compared to other fuels.