Potential role of fire retardant-treated polyurethane foam as a source of brominated diphenyl ethers to the US environment Robert C. Hale * , Mark J. La Guardia, Ellen Harvey, T. Matt Mainor Department of Environmental Sciences, Virginia Institute of Marine Science, College of William and Mary, P.O. Box 1346, Gloucester Point, VA 23062, USA Abstract Five tetra- to hexabrominated diphenyl ether (BDE) congeners (BDE-47, -99, -100, -153 and -154) are the most frequently reported in wildlife and humans. The commercial penta-BDE product, used predominantly to flame-retard polyurethane foam, consists primarily of these same congeners. In 1999, North American demand accounted for 98% of the total global penta-market of 8500 metric tons. Frogs, housed with flame retardant-treated polyurethane foam as a dry substrate, accumulated 10,100 lg=kg (wet weight) of the above BDEs. Crickets kept therein as food contained 14,400 lg=kg. The crickets are believed to have browsed directly on the foam and, in turn, were consumed by the frogs. BDE congener composition in all three matrices matched that of the penta-commercial product. Similar congeners were also observed in soil and stream sediments collected near a polyurethane foam manufacturing plant. Summed con- centrations of BDE-47, -99 and -100, the dominant congeners observed in these samples, ranged from < 1to132 lg=kg (dry weight basis). Sunfish fillets obtained from a nearby, off-site pond contained a total of 624 lg=kg (lipid basis). Sewage treatment plant (STP) sludge exhibited these same congeners at 1370 lg=kg (dry weight). BDE-209, the fully brominated congener predominant in the commercial deca-BDE product, was also present at 1470 lg=kg. While no known polyurethane foam manufacturers discharged to this plant, the distribution pattern of the low brominated congeners in the sludge matched that of the penta-product. After four weeks of exposure to ambient outdoor condi- tions, the surface of flame-retarded polyurethane foam became brittle and began to disintegrate. Subsequent dispersal of these penta-containing foam fragments may be one mechanism by which these BDEs reach the environ- ment. Ó 2002 Elsevier Science Ltd. All rights reserved. Keywords: Bioaccumulation; Frog; Sewage sludge; Insect; Sediment; Soil 1. Introduction Brominated diphenyl ethers (BDEs) are widely used as additives to flame retard flammable polymers. While consumption of BDE formulations has recently de- creased in some European nations, due to potential adverse health and environmental effects, overall global demand for these products has increased, reaching 67,125 metric tons in 1999 (Renner, 2000a). BDEs ap- pear to be persistent organic pollutants (POPs) and some congeners are highly bioaccumulative, as a con- sequence they have emerged as contaminants of global concern (de Boer et al., 1998). BDE congeners with four to six bromines have been detected in biota from remote areas (de Boer et al., 2000), indicating possible long- range transport. Some studies have indicated increasing levels in the North American environment (e.g. Luross et al., 2000). Exponential increases in BDE concentra- tions in human breast milk over time in Sweden have Chemosphere 46 (2002) 729–735 www.elsevier.com/locate/chemosphere * Corresponding author. Fax: +1-804-683-7186. E-mail address: hale@vims.edu (R.C. Hale). 0045-6535/02/$ - see front matter Ó 2002 Elsevier Science Ltd. All rights reserved. PII:S0045-6535(01)00237-5