| Polybrominated Diphenyl Ethers: Occurrence, Dietary Exposure, and Toxicology Per Ola Darnerud,1 Gunnar S. Eriksen,2 Torkell Jóhannesson,3 Poul B. Larsen,4 and Matti Viluksela5 1National Food Administration, Toxicology Division, Uppsala, Sweden; 2Norwegian Food Control Authority, Olso, Norway; 3University of Iceland, Department of Pharmacology, Reykjavik, Iceland; 4Danish Environmental Protection Agency, Copenhagen, Denmark; 5National Public Health Institute, Laboratory of Toxicology, Kuopio, Finland Abstract Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in plastics (concentration, 5-30%) and in textile coatings. Commercial products consist predominantly of penta-, octa-, and decabromodiphenyl ether mixtures, and global PBDE production is about 40,000 tons per year. PBDEs are bioaccumulated and biomagnified in the environment, and comparatively high levels are often found in aquatic biotopes from different parts of the world. During the mid-1970-1980s there was a substantial increase in the PBDE levels with time in both sediments and aquatic biota, whereas the latest Swedish data (pike and guillemot egg) may indicate that levels are at steady state or are decreasing. However, exponentially increasing PBDE levels have been observed in mother's milk during 1972-1997. Based on levels in food from 1999, the dietary intake of PBDE in Sweden has been estimated to be 0.05 µg per day. Characteristic end points of animal toxicity are hepatotoxicity, embryotoxicity, and thyroid effects as well as maternal toxicity during gestation. Recently, behavioral effects have been observed in mice on administration of PBDEs during a critical period after birth. Based on the critical effects reported in available studies, we consider the lowest-observed-adverse-effect level (LOAEL) value of the PBDE group to be 1 mg/kg/day (primarily based on effects of pentaBDEs) . In conclusion, with the scientific knowledge of today and based on Nordic intake data, the possible consumer health risk from PBDEs appears limited, as a factor of over 106 separates the estimated present mean dietary intake from the suggested LOAEL value. However, the presence of many and important data gaps, including those in carcinogenicity, reproduction, and developmental toxicity, as well as additional routes of exposure, make this conclusion only preliminary. Moreover, the time trend of PBDEs in human breast milk is alarming for the future. Key words: brominated, diet, environmental levels, exposure, flame retardant, human, organohalogen compounds, toxicity. -- Environ Health Perspect 109(suppl 1) :49-68 (2001) . http://ehpnet1.niehs.nih.gov/docs/2001/suppl-1/49-68darnerud/abstract.html The full version of this article is available for free in HTML format. |