Levels,Congener Group Profiles And Risk Assessments Of Short-chain And Medium-chain Chlorinated Paraffins In Soil From Industrial Areas

Chlorinated paraffins(CPs)are persistent organic pollutants which can be released into the environment during the production and industrial use.CPs in the environment distribute into soil through atmospheric migration and sedimentation,resulting in the pollution of CPs in the soil.Industrial production and solid waste treatment are the main sources of CPs to the environment,which can cause environmental problems.However,few studies have investigated transport pathways of CPs released by industrial production and solid waste treatment in the industrial areas.In this study,we selected the soil samples(0～20 cm)as the research objects through sample collection,laboratory experiment and mathematical analysis to explore the levels,congener group profiles and risk assessments of short-chain and medium-chain chlorinated paraffins in industrial areas of paper mill plant,metal smelting plant and soild waste treatment plant.The main results obtained are as follows:(1)The levels of SCCPs and MCCP s in soil from industrial areas of paper mill plant,metal smelting plant and soild waste treatment plant were analyzed by GCxGC-ECNI-MS as follows:①The levels of SCCPs and MCCPs in soil of paper mill plant were 42～3853 ng/g and 34～2091 ng/g,respectively.The levels of SCCPs and MCCPs in soil of metal smelting plant were 173～2146 ng/g and 205～3957 ng/g,respectively.The levels of SCCPs and MCCPs in soil of soild waste treatment plant were 73-3842 ng/g and 116～8819 ng/g,respectively.②The levels of SCCPs in soil of paper mill plant,metal smelting plant and soild waste treatment plant were 2～3 times,2～9 times,and 3～4 times higher than those in Yunnan,respectively.The levels of MCCPs in soil of paper mill plant,metal smelting plant and soild waste treatment plant were 4～19 times,26～36 times,and 15～81 times higher than those in Yunnan,respectively.③The levels of SCCPs in each sampling area was distributed in the following order:paper mill plant>solid waste treatment plant>metal smelting plant.The levels of MCCPs in each sampling area was distributed in the following order:solid waste treatment plant>metal smelting plant>paper mill plant.(2)The congener group profiles of SCCPs and MCCPs in soil from industrial areas of paper mill plant,metal smelting plant and soild waste treatment plant were analyzed by GC×GC-ECNI-MS as follows:①The C10Cl6-7 and C14-15Cl5 homolog groups were the dominant SCCPs and MCCPs in soil of paper mill plant,contributing 35.6%and 31.6%,respectively.Principal component analysis indicated that CP 52(CP 52Ⅰ,CP 52Ⅲ)commercial products may be sources of SCCPs and MCCPs in soil of paper mill plant.②The C10Cl6-7 and C14-15Cl7-8 homolog groups were the dominant SCCPs and MCCPs in soil of metal smelting plant,contributing 27.0%and 52.5%,respectively.Principal component analysis indicated that CP 42,CP 52(CP 52Ⅰ,CP 52Ⅲ),CP 70 commercial products may be sources of SCCPs and MCCPs in soil of metal smelting plant.③The C10-11Cl7-8 and C14-15Cl7-8 homolog groups were the dominant SCCPs and MCCPs in soil of soild waste treatment plant,contributing 30.0%and 44.8%,respectively.Principal component analysis indicated that CP 52(CP 521,CP 521Ⅰ,CP 52Ⅲ)commercial products may be sources of SCCPs and MCCPs in soil of soild waste treatment plant.(3)The ecological risks of SCCPs and MCCPs in soil from industrial areas of paper mill plant,metal smelting plant and soild waste treatment plant were assessed by the risk quotient as follows:①The average RQ values for SCCPs in soil of paper mill plant were 0.12,which were in the medium risk range.The average RQ values for MCCPs in soil of paper mill plant were 0.02,which were in the low risk range.②The average RQ values for SCCPs in soil of metal smelting plant were 0.10,which were in the medium risk range.The average RQ values for MCCPs in soil of metal smelting plant were 0.03,which were in the low risk range.③The average RQ values for SCCPs in soil of soild waste treatment plant were 0.10,which were in the medium risk range.The average RQ values for MCCPs in soil of soild waste treatment plant were 0.05,which were in the low risk range.(4)The health risks for human in the paper mill plant,metal smelting plant and soild waste treatment plant were assessed by appropriate models as follows:①The highest daily exposure values for adults and children in the paper mill plant were 8.81×10-3 and 4.21×10-2μg/(kg·d),respectively.②The highest daily exposure values for adults and children in the metal smelting plant were 9.05×10-3 and 4.32×10-2 μg/(kg·d),respectively.③The highest for adults and children in the soild waste treatment plant were 1.88×10-2 and 8.96×10-2μg/(kg·d),respectively;④The human exposure values of children and adults were lower than tolerable daily intake(TDI,10 pg/kg/day)given by Canadian Environmental Protection Act,suggesting that non-dietary exposure under typical industrial areas were low.