Study On Distribution Characteristics Of Microplastics And Endocrine-disrupting Compounds In Zhoushan Coastal Area

The emerging contaminants in the oceans and coastal areas are hot topics that have been discussed seriously in the world in recent years.Microplastics(particle size<5 mm)and endocrine-disrupting compounds are both emerging contaminants.These pollutants spread and accumulate in land and water around the world.After being ingested,they could pass through the food chain and enlarge the threaten to human health.At present,the number of relevant studies on emerging contaminants have increased at a fast rate.However,there is a considerable lack of relevant studies on coastal areas in the East China Sea of China.In this study,we selected the Zhoushan Islands as the research area,it's the largest archipelago in China.We investigated the pollution caused by typical contaminants of emerging concern(CECs),including endocrine-disrupting compounds(EDCs)and microplastics(MPs),in sediment,seawater,and aquatic animals collected from Zhoushan Islands.The characteristics and abundance of microplastics in typical beaches and the interaction and distribution of microplastics were studied.The surface micro-morphology of microplastics was observed and analyzed.The contamination of seawater and aquatic animals in aquaculture areas was studied and provided the methods of microplastics pollution detection and characterization.Our research also expanded the basic data of the pollution of emerging contaminants in the coastal zone and aquaculture areas.Microplastics were found in all collected samples(sediment,seawater and animals),indicating that they were ubiquitous contaminants in the marine environment.The average concentrations of microplastics in sediments,seawater,and animals ranged from 63.7±3.7to 4292.2±59.6 n/kg,16.6±4.3 to 27.8±15.1 n/m~3,and 307.9±9.5 to 1798.8±57.4 n/kg,respectively.To the best of our knowledge,this is a comprehensive study to assess the spatial distribution variations of CEC pollution in Zhoushan of China.The results provide the available data to carry out removal management measures and the ecological risk assessments.Bisphenol A(BPA)and organochlorine pesticides were not detected in all collected samples from seawater and aquatic animals.The compound 4-nonylphenol(4-NP)was detected in seawater(2.94–6.70 ng/L)and animals(Mytilus coruscus,104.40 ng/g;Ostrea rivularis Gould,11.86 ng/g).Natural steroids were detected in aquatic animals(0.24–9.36ng/g).Microplastics of different shapes(mainly fragment,pellet/granule,film,line/fiber and foam)with the different weathered surface textures(mainly grooves,fractures,mechanical pits,flakes,and granular and solution pits)were identified as polyethylene(PE),polypropylene(PP),polystyrene(PS),polyamide(PA),acrylonitrile-butadiene-styrene(ABS),polyethylene terephthalate(PET),and the blend of biaxially oriented polypropylene(BOPP)and polypropylene ethyl ester(PES)by the Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy(ATR-FTIR)technique.These weathered surface textures of microplastics in the environment will make them easier to adsorb and enrich other pollutants or organisms.Therefore,further studies should pay more attention to the the binding mechanism and toxicology of endocrine-disrupting compounds and microplastics.