Historically Polluted Area Increases Human Exposure Risks to Polychlorinated Naphthalenes through Waterfowl Egg Consumption

Abstract

Polychlorinated naphthalenes (PCNs), which are ubiquitous in the environment, are listed as persistent organic pollutants under the Stockholm Convention. Poultry can be exposed to PCNs via feed and breeding environments, leading to PCNs accumulation in eggs. However, information on PCNs in eggs from waterfowl raised in contaminated regions is scarce. In this study, waterfowl and chicken eggs were collected from a historically polluted area in Hunan Province, China. In addition, waterfowl eggs were collected from Guangxi Province as a control. The mean concentrations of Σ₇₅PCNs in waterfowl (30.8 pg/g wet weight [ww]) and chicken eggs (26.1 pg/g ww) from Hunan were significantly higher than in waterfowl eggs (15.6 pg/g ww) from Guangxi. The PCN homologue profiles in poultry eggs from the two regions varied, but both were dominated by lower chlorinated CNs. Correlation analysis showed that breeding environment made a greater contribution to PCNs in waterfowl eggs. Interestingly, PCNs and polychlorinated biphenyls (PCBs) showed a significant positive correlation in samples from Hunan, but not in those from Guangxi. Human exposure to PCNs and PCBs was higher through consumption of poultry eggs from historically contaminated areas.