Abstract:Biomass burning are typical combustion sources of PAHs in rural China. In this study, emissions of gaseous and particulate PAHs from typical biomass burning types were measured by laboratory simulations using a self-designed dilution chamber system under real combustion conditions. Rice straw, corn stalk, peanut stem and soybean stalk were burned in a cook stove to simulate water boiling tests. Rice straw, corn stalk, peanut stem, litchi leaves, and leaves from Ficus virens and Ficus microcarpa were burned in an open platform to simulate field burning activities. Emission factors of three typical burning types, including crop residues open burning, foliage open burning and indoor crop residue combustion were higher than previously reported values, respectively. Spectral distributions of emitted PAHs from above burning types were similar. Medium to high-ring PAHs accounted for 22.2% to 28.8% of total PAHs emitted from biomass burning. PAHs diagnostic ratios as indicators of certain pollutants sources may introduce significant uncertainty, when they were adopted in source apportionments of atmospheric PAHs.