Occurrence and exposure to polycyclic aromatic hydrocarbons and their derivatives in a rural Chinese home through biomass fuelled cooking

The concentration and composition of PAHs emitted from biomass cooking fuel were characterized in a rural non-smoking household in northern China. Twenty-two parent PAHs (pPAHs), 12 nitro-PAHs (nPAHs), and 4 oxy-PAHs (oPAHs) were measured in the kitchen, bedroom, and outdoors during both summer and winter. The most severe contamination occurred in the kitchen in the winter, where the daily mean concentrations of pPAHs, nPAHs, and oPAHs were 7500 ± 4100, 38 ± 29, and 8400 ± 9200 ng/m3, respectively. Our results suggest that the nPAHs were largely from secondary formation in ambient air while oPAHs were either from primary emission of biomass burning or secondary formation from pPAHs in the kitchen. The daily mean benzo(a)pyrene equivalent exposure concentration was as high as 200 ± 160 ng/m3 in the winter for the housewife who did the cooking compared to 59 ± 37 ng/m3 for the control group that did not cook.

► Very high levels of parent PAHs, nitro-PAHs, and oxy-PAHs were detected in a rural non-smoking household in northern China. ► The PAHs measured in the bedroom air were primarily from the kitchen in the winter and from ambient air in the summer. ► The nPAHs were largely from secondary formation in ambient air, while oPAHs were either from primary emission of biomass burning or secondary formation. ► The daily mean benzo(a)pyrene equivalent exposure concentration was as high as 200 ± 160 ng/m3 in the winter for the cooking housewife.