Extreme Exposure Levels of PCDD/Fs Inhaled from Biomass Burning Activity for Cooking in Typical Rural Households

Polychlorinated
dibenzo-p-dioxins and dibenzofurans
(PCDD/Fs), emitted during biomass combustion, are carcinogenic chemicals.
The association between indoor biomass burning and PCDD/Fs inhalation
exposure levels is still poorly understood. This study first reports
direct measurement of personal exposure to PCDD/Fs in real-world households
with wood combustion. In homes where biomass burning is used for cooking,
toxic equivalent quantity (TEQ) PCDD/Fs concentrations were found
to be 545 ± 251 fg I-TEQ/m3 in kitchens, with levels
of 4.5-, 6.9-, and 13.3-fold higher than those in living rooms (122
± 92 fg I-TEQ/m3), bedrooms (79 ± 27 fg I-TEQ/m3), and ambient air (41 ± 15 fg I-TEQ/m3),
respectively. PCDD/Fs exposure levels in populations using biomass
fuels for cooking (353 ± 110 fg I-TEQ/m3) were 4.3-fold
higher than those in the control groups (82 ± 32 fg I-TEQ/m3). Additionally, the average cancer risks for biomass cooking
person were approximately 3.1-fold higher than those in factory workers.
Overall, residents of household that use biomass fuels for cooking
have the highest known risk of PCDD/Fs exposure. These results highlight
that aiming to mitigate the PCDD/Fs exposure risk in the general population,
the focus of dioxin emission source control measures should shift
from industrial sectors to residential biomass combustion.