A novel pollution pattern: Highly chlorinated biphenyls retained in Black-crowned night heron (Nycticorax nycticorax) and Whiskered tern (Chlidonias hybrida) from the Yangtze River Delta

Contamination of organochlorine pesticides (OCPs), polychlorinated diphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and their methylated counterparts (MeO-PBDEs) were determined in Black-crowned night heron (Nycticorax nycticorax) and Whiskered tern (Chlidonias hybrida) from two drinking water sources, e.g. Tianmu lake and East Tai lake in Yangtze River Delta, China. A novel PCBs contamination pattern was detected, including 11% and 6.9% highly chlorinated biphenyls (PCBs with eight to ten chlorines) in relation to total PCB concentrations in the Black-crowned night heron and Whiskered tern eggs, respectively. The predominating OCPs detected in the present study were 4,4′-DDE, with concentration range 280–650 ng g−1 lw in Black-crowned night heron and 240–480 ng g−1 lw in Whiskered tern, followed by β-HCH and Mirex. 6-MeO-BDE-90 and 6-MeO-BDE-99 are the two predominant congeners of MeO-PBDEs whereas 6-OH-BDE-47 contributes mostly to the OH-PBDEs in both species. Contamination level was considered as median or low level compared global data. [Display omitted] •A number of POPs were determined in two water bird eggs from Yangtze River Delta.•Highly chlorinated biphenyls (CB194-209) were detected in all individual eggs.•4,4′-DDE was the predominant pesticide in all samples, followed by β-HCH and Mirex.•The exposure level of POPs was in the median or low level in the world.