The PM2.5 exposure concentrations observed in our
study were higher than the 24-h urban ambient air
concentrations in Shanghai (mean: 68 lg/m3
; range:
21–147 lg/m3
) and Beijing (mean: 101 lg/m3
; range:
39–149 lg/m3
) (Ye et al., 2003; Zheng et al., 2005), but
lower than the average personal exposure levels
observed in a very small sample of individuals cooking
with biomass in rural northeastern China (14-h
mean ± s.d.: 143 ± 344 lg/m3 in summer) (Jiang
and Bell, 2008). The lower exposure in our study could
be related to the low ambient pollution levels in our
study region (Zhang et al., 2008) and the more vented
kitchens compared with the better-sealed households in
northern China.