Study On The Contamination Profiles Of Polychlorohydrocarbons And Organophosphorus Flame Retardants In The Qingyuan Section Of Beijiang River

Beijiang River is an important part of the Pearl River system and is one of the main rivers in Guangdong Province.The Qingyuan section of the Beijiang River flows through the cities of Yingde and Qingyuan.In recent years,environmental problems have been concerned by people with the rapid economic development and the increase in industrial and agricultural activities.In order to study the environmental problems in the Qingyuan section of Beijiang River,we collected the sediment and fish tissue samples from the Beijiang River in August 2015,detected the concentrations of polychlorohydrocarbons(PCHs)and organophosphorus flame retardants(OPFRs)by gas chromatography-triple quadrupole tandem mass spectrometry(GC-MS/MS),investigated the contamination profiles and spatial distribution of PCHs and OPFRs in sediments and fish tissue samples in the Qingyuan section of Beijiang River,and evaluated the ecological and human health risks posed by PCHs and OPFRs.This study provides essential evidence for fully understanding the occurrence and potential risk of PCHs and OPFRs in the Qingyuan section of the Beijiang River.The main conclusions of this study are as follows:PCHs were detected in the sediment and wild fish tissue samples from the Beijiang River.The detection frequencies were 82%–100% for sediment and 79%–100% for fish tissues.The concentrations of HCBD and HCB were weakly associated with the sown area of fruits,the sown area of crops,the number of chemical manufacturing plants,and the total emission of industrial gases,while there was a weak correlation between the number of textile enterprises and the levels of PCA.The principal component analysis showed obvious separation between 1,2,4-trichlorobenzene(TCB)and other chlorinated organic pollutants.Combined with the result of Spearman correlation analysis between pollutant concentrations and their corresponding log Kow values,some trichlorobenzene was found to be the result of reductive dechlorination of higher chlorinated benzenes.There was no obvious ecological and human health risk posed by PCHs and OPFRs in the investigated area.OPFRs were detected in sediment samples,with detection frequencies of 85%-100%.Tris(butoxyethyl)phosphate(TBOEP),tris(2-chloroisopropyl)phosphate(TCPP),tris(2-ethylhexyl)phosphate(TEHP),and triphenyl phosphate(TPHP)were dominant in the sediment.For wild fish tissue,most OPFRs were found with detection frequencies of66%-97%.The primary pollutant in fish tissue was triethyl phosphate(TEP).By exploring the correlation with the basic information of investigated regions,the OFPR distribution in sediment was related to industrial and agricultural activities.The correlation analysis between different OPFR concentrations showed that the e-waste recycling activity affected the concentrations of TBOEP,TCPP,TEHP,and TPHP,suggesting their emission from e-waste dismantling plants.Ecological risk assessment indicated that,at specific sampling sites,TPHP posed a medium risk and a high risk,and ethylhexyl diphenyl phosphate(EHDPP)and TBOEP caused a medium risk.The rest OPFRs did not show any risks to aquatic organisms.Besides,the intake of OPFRs through fish consumption will not cause harm to humans.PCHs were listed in the Stockholm Convention and are considered priority pollutants by different countries,while OPFRs are emerging flame retardants.Our results demonstrate the residue of PCHs in the aquatic environment of China,update the existing data on OPFR pollution,and become the basis of further toxicological studies of these pollutants.