Ecological safety of paraquat with particular reference to soil
1997
Dyson, J.S. (ZENECA Agrochemicals, Jealott's Hill Research Station, Bracknell, Berkshire (United Kingdom))
The safety of the environment is examined, with particular reference to crops and other organisms living in the soil. The examination uses both toxicity and exposure, which is a key principle to assessing the potential risks of chemicals on a scientific basis. As a result, paraquat has a low impact on non-target organisms in both terresterial and acquatic environments, and does not bioaccumulate. In soil, the rapid adsorption and strong binding of paraquat to soil reduce exposure to paraquat massively, ensuring that crops are not harmed and do not contain residues of paraquat. Paraquat is the only residue of concern because the intermediate metabolites are never present in large quantities. While adsorption to soil slows down the degradation rate of paraquat compared to that occuring on leaf surfaces, it does not result in the indefinite increase of paraquat residues in soil form the continued use of paraquat. The residues of paraquat remain in soil not posing a significant risk to the environment, and not moving to surface water or groundwater by runnoff or leaching. Overall, the safety and benefits of using paraquat as a herbicide, particularly as an integral part of soil conservation management, mean that it will continue to be used extensively throughout the world.
显示更多 [+] 显示较少 [-]