Uptake Of Polybrominated Diphenyl Ethers Research Articles

Polybrominated diphenyl ether flame retardants in lichens and mosses from King George Island, maritime Antarctica

Lichens and mosses are considered good indicators of atmospheric pollution as they absorb contaminants directly from the air. Polybrominated diphenyl ethers (PBDEs) are man-made chemicals used as flame retardants in materials such as plastics, textiles, electronic circuitry and furnishing foam. Few studies have investigated PBDEs in the southern hemisphere including Antarctica. This paper presents the first evaluation of PBDEs in lichens ( Usnea antarctica and Usnea aurantiaco-atra) and mosses ( Sanionia uncinata) collected at King George Island, maritime Antarctica. PBDEs were detected at low levels in all lichen and moss samples. On average, the levels of PBDEs in mosses (818 pg g −1 dry weight; 101 ng g −1 lipid) were significantly higher than in lichens (168 pg g −1 dry weight; 9.11 ng g −1 lipid). This difference is most likely due to the differing mechanisms of PBDEs uptake from the atmosphere which are controlled by a number of chemical, environmental and plant variables. Contaminant concentrations were not statistically different at sites close to and distant from human facilities. Long-range atmospheric transport is believed to be the primary source of PBDEs to King George Island. The pattern of congeners in plants resembles those found in commercial mixtures of Penta-BDE. In addition, the presence of BDE-183 in lichens and mosses suggests that other technical formulations (e.g., Octa-BDE and Deca-BDE) have reached Antarctica. Further studies are needed to better understand the role of Antarctic vegetation as a sink for anthropogenic organic pollutants.

Fate of pentabrominated diphenyl ethers in soil: abiotic sorption, plant uptake, and the impact of interspecific plant interactions.

Polybrominated diphenyl ethers (PBDEs) are potentially harmful and persistent environmental pollutants. Despite evidence that soils are a major sink for PBDEs, little is known regarding their behavior in this medium. An environmentally relevant level of a commercial penta-BDE mixture (75 microg kg(-1)) was added to topsoil, and the extractability of three congeners (BDE-47, -99, and -100) was monitored over 10 weeks in planted and unplanted treatments. The extractability of each congener decreased rapidly in the experimental soil due largely to abiotic sorption to soil particles, which was demonstrated by low PBDE recovery from sterilized and dry soils. Monoculture plantings of zucchini and radish did not affect the recovery of PBDEs from soil. However, PBDE recovery from mixed species plantings was nearly 8 times higher than that of unplanted and monoculture treatments, indicating that interspecific plant interactions may enhance PBDE bioavailablity in soil. Evidence for competitive interactions between the two species was revealed by reduced shoot biomass of zucchini plants in mixed treatments relative to pots containing only zucchini. Both plant species accumulated PBDEs in root and shoot tissue (<5 microg kg(-1) plant tissue). PBDE uptake was higher in zucchini, and translocation of PBDEs to zucchini shoots was congener-specific. Our results suggest that although abiotic sorption may limit the potential for human exposure to PBDEs in soil, plants may increase the exposure risk by taking up and translocating PBDEs into aboveground tissues and by enhancing bioavailability in soil.