Studies on the sources of benzo[a]pyrene in grain and aboveground tissues of rice plants.
July 3rd, 2008 | by admin |Studies on the sources of benzo[a]pyrene in grain and aboveground tissues of rice plants.
Rice plant pot experiments designed to identify benzo[a]pyrene (B[a]P) sources in plant tissues were conducted in an air-quality controlled greenhouse built to prevent contamination from B[a]P air pollution. Results from quartz sand cultures with control and 50, 100 and 500mugkg(-1) of B[a]P treatments were compared with those from outdoor field experiments, in which rice plants were exposed to polluted air in the urban area of Shenyang, China. When B[a]P was strictly controlled in both air and quartz sand culture medium, the background values of B[a]P in rice plant tissues were uniformly very low. There was no significant difference of B[a]P contents of rice grain between control and treatments of B[a]P in controlled air quality trials. This indicated that the source of B[a]P in the rice grains is not from any B[a]P in the root culture media. The B[a]P content of rice grain, husk, and stem with leaf sampled from outdoor field was up to 7.33-, 9.21- and 27.10-fold higher than corresponding tissues from air-quality controlled conditions. This indicated that polluted air is the main source of B[a]P in aboveground tissues. Therefore control of B[a]P pollution in ambient air is of prime importance for improving the quality of cereal crops.
Li P, Li X, Stagnitti F, Zhang H, Lin X, Zang S, Zhuo J, Xiong X.
Institute of Applied Ecology, Chinese Academy of Sciences, PO Box 417, Shenyang 110016, China.