Occurrence, distribution and bioremediation of endocrine disrupting chemicals in coastal sediments from Macao SAR, China

Introduction: The presence of endocrine disrupting chemicals (EDCs) in municipal and industrial effluents is a major issue for marine and coastal environments near big cities and the situation of the Pearl River Delta (PRD), China, is particularly interesting as it is one of the most densely populated area of the world. The occurrence of EDCs in the PRD region is well documented but specific data related to Macau is still unavailable. The levels of bisphenol-A (BPA), estrone (E1), 17α-estradiol (αE2), 17β-estradiol (βE2), estriol (E3), and 17α-ethynylestradiol (EE2) were measured from sediment samples collected along the coastline and intracoastal waterway of Macau. Methods: Simultaneous analysis of six EDC’s in sediments was performed by using a combination of ultra-sonicated and solid phase extraction, followed by silica gel fractionation, derivatization with dansyl chloride, and determination by LC/MS. Additionally, the sediment samples were used for biodegradation assays in order to evaluate the capacity of the ecosystem to degrade BPA and BPS which were measured by HPLC. Results: BPA was found in all 46 collected samples; Lower values were associated with the presence of mangrove trees; Bacterial diversity is higher in the presence of BPS than of BPA; After 10 days, BPS was still present in most samples, although full degradation of BPA was achieved in a few days in all samples. Final remarks: Mangrove trees seem to facilitate the degradation of BPA. However, slower degradation of BPS may cause accumulation in sediments. Ongoing characterization of the microorganisms present in the collected sediments may contribute to the development of new bioremediation strategies.