() PAH uptake in wheat grain.
Kobayashi, R1, Okamoto, R2, Maddalena, R3, Kado, N1, 2, 1 University of California, Davis, Davis, CA, USA2 California EPA, Air Resources Board, Sacramento, CA, USA3 Lawrence Berkeley National Laboratory, Berkeley, CA, USA
ABSTRACT- Polycyclic aromatic hydrocarbons (PAHs) are introduced into the environment mainly by combustion processes. Although inhalation is known to be an important pathway for certain occupational exposures, dietary intake can contribute significantly to PAH exposure for the general population. Studies have indicated that grains and vegetables are an important source of dietary PAHs. We have previously reported measurable levels of PAHs in wheat grain grown in California and that PAH levels varied by geographic location. Air-to-plant transfer processes are thought to be the main contamination pathway, but there is very little quantitative information regarding potential accumulation and transport through agricultural food chains. We conducted controlled exposure chamber experiments to study the relationship between PAH levels in wheat grain and in air and to explore potential mechanisms of airborne PAH deposition and absorption. The most abundant PAHs found in California grain were introduced into the air of an exposure chamber where mature wheat plants were placed. PAH uptake by wheat grain was monitored over a period of a month. The relationship between PAHs in air and plants was investigated and potential human exposure to PAHs through ingestion of wheat was evaluated.
Key words: Plant uptake, PAHs, Human exposure