Submitted to: International Journal of Phytoremediation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2002
Publication Date: 12/15/2002
Interpretive Summary: Plant species are generally selected for phytoremediation of selenium based on their ability to extract large amounts of selenium. The potential biological and environmental risks involved need to be addressed when developing phytoremediation practices. We are investigating the biotransfer of accumulated selenium as part of our efforts to reduce Se contamination in western United States. In several studies related to the biotransfer of Se we determined that: 1) feeding behavior of insects was affected not only by the concentration of Se in plant tissue, but also by the mobility of the insects and choice of feed available; 2) levels of Se increased in animal tissues of rabbits, sheep, and dairy cows feed selenium enriched canola or alfalfa; 3) precancerous colon lesions were reduced in rats fed selenium-enriched broccoli. Results of our studies clearly show that biotransfer of Se does occur. The effects of this transfer do not appear to be hazardous, and may even be beneficial for increasing selenium content in different biological systems.
Technical Abstract: Phytoremediation is the use of plants to remediate soils and water that are contaminated with organic and/or inorganic pollutants, e.g., Se. Selenium at high concentrations is not only potentially harmful to a biological system, but is also an essential trace element for normal nutrition and health of animals. This paper discusses a series of experiments that evaluated the biotransfer possibilities of Se from plants used in Se phytoremediation to insects and animals. We identified the biotransfer of Se in the following: 1) cabbage looper larvae avoided feeding upon canola leaves with high Se concentrations and resorted to a form of cannibalism; 2) populations of beet armyworm were reduced when fed different Atriplex plant lines irrigated with 'Se-enriched water; 3) levels of Se increased in blood, liver, and kidneys of lambs fed Se-enriched leaves from canola irrigated with Se-laden effluent; 4) Se-containing broccoli was effective for inhibiting preneoplastic lesions in the colons of rats. These studies demonstrate that Se absorbed by plants used in phytoremediation can be transferred biologically in an intentional or unintentional manner to insects and animals.