Persistent pollutants in land-applied sludges

Disposal of sewage sludge by application to agricultural and other land is widely practised and is presumed to be environmentally beneficial, but we have found high concentrations of an environmentally persistent class of organic pollutants, brominated diphenyl ethers (BDEs), in 'biosolids' from four different regions of the United States. These compounds are widely used as flame retardants, and their presence suggests that the environmental consequences of land application of biosolids need further investigation. We also frequently detected BDEs in wild-caught fish, indicating another pathway for human exposure.