PBDEs in Italian sewage sludge and environmental risk of using sewage sludge for land application

Polybrominated diphenyl ethers (PBDEs) were determined in sewage sludge samples collected from eight Italian wastewater treatment plants (WWTPs) between June 2009 and March 2010. Total PBDE concentrations ranged from 158.3 to 9427 ng g−1 dw, while deca-BDE (BDE-209) (concentrations ranging from 130.6 to 9411 ng g−1 dw) dominated the congener profile in all the samples, contributing between 77% and 99.8% of total PBDE. The suitability of using a magnetic particle enzyme-linked immunoassay (ELISA) to analyse PBDEs in sewage sludge was also tested. The ELISA results, expressed as BDE-47 equivalents, were well correlated with those obtained by GC–NCI–MS, with correlation coefficients (r2) of 0.899 and 0.959, depending on the extraction procedure adopted. The risk assessment of PBDEs in sewage sludge addressed to land application was calculated. PECsoil values compared to the relative PNECsoil for penta and deca-BDE suggests that there is a low risk to the soil environment.

► PBDEs in sewage sludge were determined in eight Italian WWTPs for the first time.
► PBDEs concentrations showed differences between the eight investigated WWTPs.
► Deca-BDE (BDE-209) was the dominant congener in all samples.
► The suitability of using ELISA method to analyse PBDEs in sewage sludge was tested.
► The risk assessment of using sewage sludge for land application was evaluated.