Halogenated flame retardants (HFRs) and perfluroalkyl substances (PFASs) are considered crucial components in manufacturing a wide variety of consumer products. Well-known examples of HFRs and PFASs are polybrominated diphenyl ethers (PBDEs) as well as perfluorooctane sulfonate (PFOS), respectively. Due to their persistence, toxicity, bioaccumulation and long-range transport potential, these chemicals have been added to the Persistent Organic Pollutants (POPs) list of the Stockholm Convention. Since the worldwide restriction on their production and use, the demand for these compounds is expected to decline, whereas that for their alternatives is projected to increase. Although these chemicals are banned or voluntarily phased out in the developed countries, some of these emerging POPs such as PFOS and PFOS-related chemicals are still produced in China currently. As Pearl River Delta (PRD) region is one of the most heavily industrialized and urbanized regions in China, it is conceivable that this region is contaminated by HFRs, PFASs and their replacements. Our recent monitoring study carried out in South China Sea has revealed that the highest PBDEs and PFAS concentrations in the environmental samples were observed in the region of PRD. HFRs and PFASs have emerged as global environmental contaminants, however, the information on these persistent toxic substances, particularly the changes in levels and patterns of their alternatives, is still very limited in the region. This study, therefore, aims to examine temporal trends in concentrations of HFRs and PFASs in two species of marine mammals, the Indo-Pacific humpback dolphin (Sousa chinensis) and finless porpoise (Neophocaena phocaenoides), in the PRD region of China. In addition, a preliminary risk assessment on these ecologically important marine species due to exposure to these groups of persistent and toxic substances was also conducted in this study.
|Publication status||Published - Jun 2016|