Emission and size distribution of particle-bound polycyclic aromatic hydrocarbons from residential wood combustion in rural China

摘要

Emissions and size distributions of 28 particle-bound polycyclic aromatic hydrocarbons (PAHs) from residential combustion of 19 fuels in a domestic cooking stove in rural China were studied. Measured emission factors of total particle-bound PAHs were 1.79 ± 1.55, 12.1 ± 9.1, and 5.36 ± 4.46 mg kg ~1 for fuel wood, brushwood, and bamboo, respectively. Approximate 86.7, 65.0, and 79.7% of the PAHs were associated with fine particulate matter with size less than 2.1 μm for these three types of fuels, respectively. Statistically significant differences in emission factors and size distributions of particle-bound PAHs between fuel wood and brushwood were observed, with the former had lower emission factors but more PAHs in finer PM. Mass fraction of the fine particles associated PAHs was found to be positively correlated with fuel density and moisture, and negatively correlated with combustion efficiency. Low and high molecular weight PAHs preferably segregated into the coarse and fine PM, respectively. The high accumulation tendency of the PAHs from residential wood combustion in fine particles implies strong adverse health impact.