Exposure And Health Evaluation Of PFOS,PFOA,and Their Precursors And Substitutes In Typical Environmental Media And In Maternal And Infant Populations

Per /polyfluoroalkyl substances(PFASs)are a class of persistent pollutants in which all or part of the hydrogen atoms in the carbon chain are replaced by fluorine atoms.They are widely used in aerospace,medical,food production and waterproof foam due to their stable and excellent properties.Numerous studies have shown that PFASs have long-range migration,toxicity,difficulty in degradation,and bioaccumulation,and numerous epidemiological studies have shown that PFASs have adverse effects on human thyroid hormones,immunity,and neonatal birth outcomes.Perfluorooctane sulfonic acid(PFOS)and perfluorooctanoic acid(PFOA)are the two most representative traditional PFASs,which were included in the Stockholm Convention on Persistent Organic Substances in 2009 and 2018,respectively,and their production and use They are subject to regulation and control.As a result,a large number of new alternatives have emerged,while more precursors have been detected frequently due to innovations in research techniques.Currently,PFASs precursors and novel substitutes are gaining more and more attention,however,there is a lack of data to support their exposure and health evaluation in the environment and population.Therefore,in this study,PFOS,PFOA and their typical precursors and surrogates were used as study subjects,and soil and bark samples were collected from the coastal soils of Huangpu River and Taihu Lake basin,and maternal blood serum was collected as biomarkers to conduct a birth cohort study in a mother-infant population,and a solid-phase extraction-ultra performance liquid chromatography-mass spectrometry(UPLC-MS)method was established to investigate the contamination exposure and health risk of PFASs in typical environmental media and characteristic population.health risks.The target contaminants included PFOS,PFOA,the precursor fluorotelomer sulfonic acid(FTS),N-ethyl-perfluorooctane sulfonamidoacetic acid(N-Et FOSAA),N methylperfluorooctane sulfonamidoacetic acid(N-Me FOSAA),the new alternative chlorinated perfluoroalkyl ether sulfonic acids(Cl PFESAs),4,8-dioxa-3-hydro-ammonium polyfluorononanoate(4,8-dioxa-3H-per-fluorononanoate,ADONA).The main subjects of this paper are as follows:(1)Total PFASs concentrations in Huangpu River coastal soils ranged from 0.514 ～ 165ng/g,with PFOA as the major detected monomer(mean ± standard deviation 9.69 ± 13.0 ng/g).The rest were PFOS(0.119 ± 0.133 ng/g)> 6:2 FTS(0.081 ± 0.034 ng/g)> 6:2 Cl-PFESA(0.053 ± 0.067 ng/g)> 8:2 Cl-PFESA(0.030 ± 0.067 ng/g),indicating that PFOS and PFOA were the main contaminants in the Huangpu River coastal soil.major pollutants.The total PFASs concentrations in the coastal soils of Taihu Lake ranged from 0.176 to 2.84 ng/g,with PFOA as the main detected monomer(0.189 ± 0.216 ng/g)and the rest in the order of NMe FOSAA(0.072 ± 0.060 ng/g)> N-Et FOSAA(0.073 ± 0.064 ng/g)> 4:2 FTS(0.046 ± 0.041ng/g)> PFOS(0.028 ± 0.028 ng/g)> 6:2 Cl-PFESA(0.020 ± 0.010 ng/g)> 8:2 Cl-PFESA(0.012 ± 0.006 ng/g),suggesting that the precursors(N-Me FOSAA,N-Et FOSAA,and 4:2 FTS)became the most important precursors of PFASs in Lake Tai PFASs were important contributors in soils along the Taihu Lake.The concentrations of total PFASs in the bark along the Huangpu River ranged from 0.298 to 57.7 ng/g,with PFOA as the major detected monomer(3.40 ± 5.78ng/g)and the rest in the order of ADONA(1.87 ± 5.82 ng/g)> 6:2FTS(0.953 ± 2.40 ng/g)>PFOS(0.072 ± 0.058 ng/g)> 4:2 FTS(0.091 ± 0.129 ng/g)> 8:2 Cl-PFESA(0.067 ± 0.068ng/g)> 6:2 Cl-PFESA(0.020 ± 0.035 ng/g).The concentrations of total PFASs in the coastal bark of Taihu Lake ranged from 0.045 to 44.0 ng/g,with 6:2 FTS as the main detected monomer(8.90 ± 8.42 ng/g),and the rest were N-Me FOSAA(4.40 ± 6.64 ng/g)> PFOA(0.877 ± 0.990ng/g)> N-Et FOSAA(0.585 ± 0.968 ng/g)> ADONA(0.230 ± 0.378 ng/g)> PFOS(0.023 ±0.019 ng/g)> 6:2 Cl-PFESA(0.005 ± 0.001 ng/g),suggesting that the precursors 6:2 FTS and N-Me FOSAA were the major contributors of PFASs in the coastal bark of Taihu Lake.The concentrations of PFOS,PFOA and 6:2 Cl-PFESA were higher in the soils of industrial areas in the Huangpu River basin than in non-industrial areas(P<0.05),and the concentration levels of 6:2 Cl-PFESA in the bark of industrial areas in the Huangpu River basin were lower than in non-industrial areas(P=0.020).The concentration levels of PFOA in soils in the Taihu Lake basin were in the order of inlet(0.305 ± 0.341 ng/g)> other points(0.177 ± 0.104 ng/g)> outlet(0.062 ± 0.024 ng/g),showing an overall decreasing pattern from west to east(P=0.047).Similar to PFOA,the concentration levels of 6:2 Cl-PFESA in soil at the inlet(0.016 ± 0.007ng/g)> outlet(0.011 ± 0.002 ng/g),P=0.006.The exposure levels of PFOS,PFOA and 6:2 ClPFESA in bark at the inlet site were significantly higher than those at the outlet(P<0.05).The ecological health risks of PFASs in soil and bark were assessed and PFASs posed little health risk to humans,plants and animals.(2)PFOA(18.5 ± 19.6 ng/m L)and PFOS(6.76 ± 9.38 ng/m L)were the major contributors and 6:2 Cl-PFESA(5.06 ± 8.56 ng/m L)was the third major contributor in 506 maternal sera in Zhejiang Province,with the rest being ADONA(0.171 ± 0.122 ng/m L)> 8.2 Cl-PFESA(0.278± 0.507 ng/m L)> 6:2 FTS(0.535 ± 2.63 ng/m L)> 4:2 FTS(0.218 ± 0.271 ng/m L).This suggests a shift from a predominantly traditional perfluorinated compound to a pattern of cooccurrence of traditional perfluorinated and novel substitutes in human serum PFASs.Maternal age,gestational cycle,and mode of delivery were significantly associated with PFASs exposure levels(P<0.05).After adjusting for maternal age,gestational cycle,prenatal BMI,gestational age and mode of delivery covariates,PFOA and 6:2 Cl-PFESA exposure had a significant inhibitory effect on neonatal birth weight,with a 1.27 % and 1.25 % decrease in birth weight per unit log increase in serum concentration,respectively.In the subgroup analysis,neonates were classified by birth weight into normal weight group(birth weight ≥ 2.5 kg)and low birth weight(LBW,birth weight < 2.5 kg)and it was found that exposure to PFOS,6:2 Cl-PFESA and 8:2 Cl-PFESA had an inhibitory effect on neonatal weight in the LBW group,with serum per unit log A 10% increase in serum per unit log concentration was associated with a 9.58%,9.26%,and 5.52% decrease in birth weight,respectively.4:2 FTS had a facilitative effect on neonatal weight in the LBW group,with a 10% increase in serum per unit log concentration associated with a 1.11% increase in birth weight.PFOS,6:2 Cl-PFESA,and 8:2 Cl-PFESA had a suppressive effect on neonatal birth length in the LBW group,with a 10% increase in serum per unit log concentration.PFOS and 4:2 FTS exposure had an inhibitory effect on neonatal Arrhenius score 5 in the LBW and normal groups,respectively,with a 10% increase in serum log concentration per unit resulting in a 2.88% and 0.30% decrease in Arrhenius score 5,respectively.Prenatal exposure to PFASs and neonatal birth There is an association between prenatal exposure to PFASs and neonatal birth outcomes,and the effect of PFASs on fetal growth and development through maternal-fetal transmission requires continued attention.