Short And Medium-Chain Chlorinated Paraffins In Serum From Residents Aged From 50-84 In Jinan:Occurrence,Composition And Association With Hematologic Parameters

Chlorinated paraffins(CPs)are synthetic mixture of chlorinated n-alkanes with carbon chain length ranging from 10-30 and chlorine content are in a range of 30%-70%on a weight.CPs are widely used in commercial products,like plasticizers,flame retardants,lubricants and coolants,and additives in paints and leather,coatings and sealants applications because of their thermal stability,flame resistance,insulativity and low cost.Due to their high toxicity,long-range atmospheric transport(LRAT)and bioaccumulation characteristics,SCCPs have been listed in Annex A of Stockholm Convention as persistent organic pollutants(POPs)in May 2017 to limit its production in the global world.Some countries such as Europe,America and Japan have taken some measures to restrict the production of CPs,but China,as the predominant country in production,use and exportation of CPs,however,to the best of our knowledge,there are no restrictive regulations on the production and use of CPs in China to date.and MCCPs with similar structures as SCCPs were dropped-in substitutes,leading to their increasing production,use and consequently detection in the environment.Nevertheless,similar structures of SCCPs and MCCPs could induce similar environmental behavior and toxicity.Therefore,MCCPs may have significant negative impacts on the environmental and human health like SCCPs.The estimations using CP concentrations in environmental media are however,deficient in characterizing the exact body burden of CPs.On the contrary,human biomonitoring,which directly measures chemicals in human fluids and tissues instead,is considered to be an effective method.In this investigation,we reported the levels of SCCPs and MCCPs in the serum samples from 145 residents(age in the range of 50～84)in Jinan,Shandong Province of China using quadrupole time-of-flight high-resolution mass spectrometry coupled with atmospheric pressure chemical ionization source operated in negative ion mode(APCI-QTOF-HRMS).The associations between serum CP concentrations and hematologic parameters were further analyzed by linear regression.SCCPs and MCCPs were detected in all the serum samples with the concentration ranging from 203.85 ng/g ww(27016 ng/g lw)and 181.12 ng/g ww(23 604 ng/g lw),respectively,indicating widespread and substantial exposure of CPs to residents in Jinan.C13 predominated in SCCP congener groups with relative abundance of 39.4%,and the relative abundance of C10-C12 are nearly identical;Cl7 and Cls accounted for 36.9%and 27.8%of all SCCP congener groups.C14 predominated in MCCP congener groups with relative abundance of 41.6%,and C13 congener group contributed 24.9%;Cl7 and Cl8 accounted for 26.4%and 27.5%of all SCCP congener groups.ΣSCCPs,YMCCPs,ΣMCCPs/ΣSCCPs and the homologue patterns presented no significant variance among age,sex and BMI groups.Further explorations revealed that perturbation of hematologic and metabolic homeostasis can be induced by CP exposure in a sex-dependent way,reflected by significant negative associations of serum SCCP and MCCP concentrations in lipid weight basis with sex-specific hematologic parameters.It is the first study exploring possible adverse effects of CP exposure to the hematologic homeostasis of residents,which provides data support for assess the pollution level and the health risks of CPs in human blood.