OPFRs And PAHs In Soils Of Zhejiang Province,China:Levels,Distribution,Sources,and Risks Assessment

As a kind of emerging pollutant,it has been proven that Organophosphorus Flame Retardants(OPFRs)have some harmful effects on human health,such as carcinogenicity,neurotoxicity,reproductive toxicity,hemolytic effects,etc.Polycyclic Aromatic Hydrocarbons(PAHs)are known as the typical organic compounds,which have caused global environmental problems for many years.Zhejiang is located in the south of Yangtze River Economic Zones,and its rapid growth of industrialization,urbanization and population has led to severe organic pollution.Soil is the origin of all the living things on earth,which is closely bound up with human health.In this situation,it is of great significance to conduct a research between environment and health.This study was carried out in Zhejiang Province,with systematical research on concentrations,distribution,source,as well as ecological and health risks assessment.The major results are as follows.(1)A Soxhlet extraction with ethyl acetate coupled with silica gel column chromatography method was developed.The gas chromatography-mass spectrometry(GC-MS)analysis revealed that the level of ∑OPFRs ranged from 9.15 to 132 ng·g-1(median 19.0 ng·g-1).TPHP and TEHP were the main compounds.The distribution in soil showed obvious spatial differences,with the concentrations decreased sharply from the north to the south.OPFR concentrations in soils from economically developed counties and intense traffic areas were much higher.(2)The content range of ∑PAHs was from 34.04 to 1990.38 ng·g-1(median 160.15 ng·g-1),with the high molecular weight PAHs dominated in soils.The level of benzo[a]pyrene(BaP)was lower than the standard of State Environmental Quality Standard for Soils in PRC(GB 15618-2018).The contaimination decreased from the costal area with density industry activities to the inland surrounded by forest.(3)Positive Matrix Factorization(PMF)model and Spearman correlation analysis indicated that OPFRs were derived from PVC-made consumer materials and transportation.Source diagnostic ratio and Principal Component Analysis suggested vehicle emission,coal and biomass combustion were the principal sources of PAHs contamination.(4)According to Nemerow’s Pollution Index,87.10%of the sampling sites showed ecological risk.Toxic equivalents of PAHs in Zhejiang Province ranged from 1.53 ng·g-1 to 268.27 ng·g-1,with 7 carcinogenic PAHs average contribution of 99.18%to the total PAHs.(5)Dermal absorption was expected to be the main exposure pathway of OPFRs,while ingestion had a higher contribution to total intakes for PAHs.Both OPFRs and PAHs posed no potential cancer risk to adults,but the carcinogenic risks to children caused by PAHs exceeded the acceptable levels,suggesting more attention should be paid to this area.