Relationship between dietary exposure and serum perfluorochemical (PFC) levels—A case study

Daily dietary intake of perfluorinated chemicals (PFCs) in relation to serum levels was assessed by determination of nine PFCs including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in matched daily diet duplicates and serum samples. Diet and serum were collected in year 2004 from 20 women in Osaka and Miyagi, Japan. Only PFOS and PFOA were detected in the diet samples and no significant difference between cities was seen. After adjusted by water content, diet concentration of PFOA was significantly higher in Osaka. The median daily intake calculated using the measured diet concentrations was 1.47 ng PFOS/kg b.w. and 1.28 ng PFOA/kg b.w. for Osaka, and 1.08 ng PFOS/kg b.w. and 0.72 ng PFOA/kg b.w. for Miyagi. A significant difference between cities was seen for the serum concentrations with median of 31 ng/mL PFOS and PFOA in Osaka, compared to 14 ng/mL PFOS and 4.6 ng/mL PFOA in Miyagi. Carboxylates such as perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUnDA) were also detected in serum at median levels 6.9 ng/mL and 3.2 ng/mL (Osaka), and 2.8 ng/mL and 5.1 ng/mL (Miyagi). Based on one-compartment model under steady state, dietary intake of PFOS and PFOA accounted for only 22.4% and 23.7% of serum levels in Osaka females, and in contrast 92.5% and 110.6% in Miyagi females, respectively.     

Time trends of perfluorinated alkyl acids in serum from Danish pregnant women 2008–2013

We aimed to estimate the levels and time trends of perfluorinated alkyl acids (PFAAs) in serum of 1533 Danish pregnant nulliparous women between 2008 and 2013. The selection criterion of only including nulliparous women was chosen to avoid confounding from parity. The serum samples were analyzed for sixteen PFAAs using solid phase extraction and liquid chromatography tandem mass spectrometry (LC-MS/MS). We investigated the time trends for seven PFAAs, which were detected in more than 50% of the samples: perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnA). We found that the serum levels of all seven PFAAs decreased during the period from 2008 to 2013; on average PFHxS decreased with 7.0% per year, PFHpS with 14.8%, PFOS with 9.3%, PFOA with 9.1%, PFNA with 6.2%, PFDA with 6.3%, and PFUnA with 7.1% per year. Adjustment for maternal age, body mass index (BMI), educational level and gestational age at blood sampling did not change the time trends much. To our knowledge, we are the first to report decreasing trends of PFNA, PFDA and PFUnA since year 2000, thereby indicating that the phase-out of these compounds are beginning to show an effect on human serum levels.     

A temporal trend study (1972-2008) of perfluorooctanesulfonate, perfluorohexanesulfonate, and perfluorooctanoate in pooled human milk samples from Stockholm, Sweden

The widespread presence of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorohexanesulfonate (PFHxS) in human general populations and their slow elimination profiles have led to renewed interest in understanding the potential human neonatal exposures of perfluoroalkyls (PFAs) from consumption of human milk. The objective of this study was to evaluate the concentrations of PFOS, PFHxS, and PFOA in pooled human milk samples obtained in Sweden between 1972 and 2008 (a period representing the most significant period of PFA production) and to see whether the time trend of these analytes parallels that indicated in human serum. Chemical analysis of PFOS, PFHxS, and PFOA was performed on pooled Swedish human milk samples from 1972 to 2008 after methodological refinements. The 20 samples which formed the 2007 pool were also analyzed individually to evaluate sample variations. Analyses were performed by HPLC-MS/MS. Due to the complexities of the human milk matrix and the requirement to accurately quantitate low pg/mL concentrations, meticulous attention must be paid to background contamination if accurate results are to be obtained. PFOS was the predominant analyte present in the pools and all three analytes showed statistically significant increasing trends from 1972 to 2000, with concentrations reaching a plateau in the 1990s. PFOA and PFOS showed statistically significant decreasing trends during 2001-2008. At the end of the study, in 2008, the measured concentrations of PFOS, PFHxS, and PFOA in pooled human milk were 75 pg/mL, 14 pg/mL, and 74 pg/mL, respectively. The temporal concentration trends of PFOS, PFHxS, and PFOA observed in human milk are parallel to those reported in the general population serum concentrations.     

Determinants of plasma concentrations of perfluoroalkyl substances in pregnant Norwegian women

BackgroundPerfluoroalkyl substances (PFASs) are widespread pollutants that have been associated with adverse health effects although not on a consistent basis. Diet has been considered the main source of exposure. The aim of the present study was to identify determinants of four plasma PFASs in pregnant Norwegian women.MethodsThis study is based in the Norwegian Mother and Child Cohort Study (MoBa) conducted by the Norwegian Institute of Public Health. Our sample included 487 women who enrolled in MoBa from 2003 to 2004. A questionnaire regarding sociodemographic, medical, and reproductive history was completed at 17 weeks of gestation and a dietary questionnaire was completed at 22 weeks of gestation. Maternal plasma samples were obtained around 17 weeks of gestation. Plasma concentrations of four PFASs (perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorononanoate (PFNA)) were examined in relation to demographic, lifestyle, dietary, and pregnancy-related covariates. Predictors were identified by optimizing multiple linear regression models using Akaike's information criterion (AIC).ResultsParity was the determinant with the largest influence on plasma PFAS concentrations, with r² between 0.09 and 0.32 in simple regression models. In optimal multivariate models, when compared to nulliparous women, parous women had 46%, 70%, 19%, and 62% lower concentrations of PFOS, PFOA, PFHxS, and PFNA respectively (p < 0.001 except for PFHxS, p < 0.01). In all these models, duration of breastfeeding was associated with reduced PFAS levels. PFOA showed the largest reduction from breastfeeding, with a 2–3% reduction per month of breastfeeding in typical cases. Levels of PFOS, PFOA, and PFNA increased with time since most recent pregnancy. While pregnancy-related factors were the most important predictors, diet was a significant factor explaining up to 4% of the variance. One quartile increase in estimated dietary PFAS intake was associated with plasma PFOS, PFOA, PFHxS, and PFNA concentration increases of 7.2%, 3.3%, 5.8% and 9.8%, respectively, resulting in small, although non-trivial absolute changes in PFAS concentrations.ConclusionPrevious pregnancies and breastfeeding duration were the most important determinants of PFASs in this sample of pregnant women.     

Association of perfluoroalkyl substances exposure in utero with reproductive hormone levels in cord blood in the Hokkaido Study on Environment and Children's Health

BackgroundExposure to perfluoroalkyl substances (PFASs) may disrupt reproductive function in animals and humans. Although PFASs can cross the human placental barrier, few studies evaluated the effects of prenatal PFAS exposure on the fetus' reproductive hormones.ObjectiveTo explore the associations of prenatal exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) with cord blood reproductive hormones.MethodsIn the prospective birth cohort (Sapporo cohort of the Hokkaido study), we included 189 mother–infant pairs recruited in 2002–2005 with both prenatal maternal and cord blood samples. PFOS and PFOA levels in maternal blood after the second trimester were measured via liquid chromatography–tandem mass spectrometry. We also measured cord blood levels of the fetuses' reproductive hormones, including estradiol (E2), total testosterone (T), progesterone (P4), inhibin B, insulin-like factor 3, steroid hormone binding globulin, follicle-stimulating hormone, and luteinizing hormone, and prolactin (PRL).ResultsThe median PFOS and PFOA levels in maternal serum were 5.2 ng/mL and 1.4 ng/mL, respectively. In the fully adjusted linear regression analyses of the male infants, maternal PFOS levels were significantly associated with E2 and positively, and T/E2, P4, and inhibin B inversely; PFOA levels were positively associated with inhibin B levels. Among the female infants, there were significant inverse associations between PFOS levels and P4 and PRL levels, although there were no significant associations between PFOA levels and the female infants' reproductive hormone levels.ConclusionsThese results suggest that the fetal synthesis and secretion of reproductive hormones may be affected by in utero exposure to measurable levels of PFOS and PFOA.     

鄱阳湖表层水中全氟辛酸和全氟辛烷磺酸污染现状调查

为阐明鄱阳湖表层水中全氟辛酸（PFOA）和全氟辛烷磺酸（PFOS）的污染现状，于2011年4月7～9日采集鄱阳湖的表层水样30份和长江水样2份，采用超高效液相色谱－三重四极杆串联质谱/质谱法检测样品中PFOS和PFOA含量，探索鄱阳湖表层水中PFOS和PFOA的污染水平及空间分布特征。结果表明： PFOS和PFOA的浓度范围分别为未检出~071 ng/L和030 ~189 ng/L，均值分别为035 ng/L和110 ng/L。而位于长江的0号点水中PFOA和PFOS含量分别为1511 ng/L和081 ng/L。鄱阳湖表层水中的PFOS和PFOA在整体上都呈现南部高于北部的趋势，这可能是由鄱阳湖的水动力条件和其周边PFCs污染源分布不同所致。以上研究结果显示，鄱阳湖表层水中PFOS和PFOA处于较低的污染水平     

Perfluoroalkyl substances in soft tissues and tail feathers of Belgian barn owls (Tyto alba) using statistical methods for left-censored data to handle non-detects

Perfluoroalkyl substances (PFASs) were investigated in tail feathers and soft tissues (liver, muscle, preen gland and adipose tissue) of barn owl (Tyto alba) road-kill victims (n = 15) collected in the province of Antwerp (Belgium). A major PFAS producing facility is located in the Antwerp area and levels of PFASs in biota from that region have been found to be very high in previous studies. We aimed to investigate for the first time the main sources of PFASs in feathers of a terrestrial bird species. Throughout this study, we have used statistical methods for left-censored data to cope with levels below the limit of detection (LOD), instead of traditional, potentially biased, substitution methods.Perfluorooctane sulfonate (PFOS) was detected in all tissues (range: 11 ng/g ww in muscle–1208 ng/g ww in preen oil) and in tail feathers (< 2.2–56.6 ng/g ww). Perfluorooctanoate (PFOA) was measured at high levels in feathers (< 14–670 ng/g ww), but not in tissues (more than 50% < LOD). Perfluorohexane sulfonate (PFHxS) could only be quantified in liver and preen oil, while other PFASs were sporadically detected in liver. PFOS levels in feathers and liver were highly correlated (r = 0.78, p < 0.01), in contrast to PFOA (r = − 0.11, p = 0.78). Combined with high PFOA levels in feathers this suggests that PFOA may be present on the external surface of feathers, due to external contamination originating from the air in the vicinity of point sources. Therefore the possibility of using feathers as a passive air sampler for high PFOA levels should be investigated in the future.     

Polyfluorinated compounds in dust from homes,offices, and vehicles as predictors of concentrations in office workers' serum

We aimed to characterize levels of polyfluorinated compounds (PFCs) in indoor dust from offices, homes, and vehicles; to investigate factors that may affect PFC levels in dust; and to examine the associations between PFCs in dust and office workers' serum. Dust samples were collected in 2009 from offices, homes, and vehicles of 31 individuals in Boston, MA and analyzed for nineteen PFCs, including perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), fluorotelomer alcohols (FTOHs), and sulfonamidoethanols (FOSEs). Serum was collected from each participant and analyzed for eight PFCs including PFOA and PFOS. Perfluorononanoate, PFOA, perfluoroheptanoate, perfluorohexanoate, PFOS and 8:2 FTOH had detection frequencies > 50% in dust from all three microenvironments. The highest geometric mean concentration in office dust was for 8:2 FTOH (309 ng/g), while PFOS was highest in homes (26.9 ng/g) and vehicles (15.8 ng/g). Overall, offices had the highest PFC concentrations, particularly for longer-chain carboxylic acids and FTOHs. Perfluorobutyrate was prevalent in homes and vehicles, but not offices. PFOA serum concentrations were not associated with PFC dust levels after adjusting for PFC concentrations in office air. Dust concentrations of most PFCs are higher in offices than in homes and vehicles. However, indoor dust may not be a significant source of exposure to PFCs for office workers. This finding suggests that our previously published observation of an association between FTOH concentrations in office air and PFOA concentrations in office workers was not due to confounding by PFCs in dust.     

Perfluorosulfonates and perfluorocarboxylates in snow and rain in Dalian,China

Samples of precipitation events (snow and rain) in Dalian, a typical coastal town in China, were analyzed for perfluorosulfonates (PFSAs) and perfluorocarboxylates (PFCAs) to investigate atmospheric contamination by these compounds. In the snow event on December 16, 2006, samples were collected from 21 different sites and in another 6 precipitation events, samples were collected from a single location. Four PFSAs (C4, C6, C8, C10) and seven PFCAs (C6–12) were analyzed. Among the homologues, perfluorooctane sulfonate (PFOS) concentrations were the highest with a geometric mean (GM) of 145 ng/L (n = 21) during the snow event on December 16, 2006, followed by perfluorooctanoate (PFOA) with a GM of 24.7 ng/L (n = 21). Concentrations of perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS) and perfluoroheptanoate (PFHpA) were more than two orders of magnitude lower than that of PFOS. Other PFSAs and PFCAs were found to be below the limit of detection in all the samples. In other 6 precipitation events, PFSAs and PFCAs were detected approximately in the same order of magnitude in both snow and rain. The results indicate that wet deposition may be a potential transport mechanism of perfluorinated chemicals in the environment.     

Perfluoroalkyl substances and thyroid function in older adults

Current understanding of the thyroid disruptive properties of perfluoroalkyl substances (PFASs), particularly in aging populations, is limited. The objectives of this study were to (i) assess associations between thyroid function, as measured by serum thyrotropin (thyroid stimulating hormone, TSH), free thyroxine (fT4), total thyroxine (T4), and total triiodothyronine (T3), and serum perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in an aging population and (ii) determine if other persistent organic pollutants with thyroid disruptive properties including polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) modify such associations. We conducted a cross-sectional study of 87 men and women 55 to 74 years of age, without clinically-diagnosed thyroid disease, who resided in upper Hudson River communities in New York. Geometric means (standard deviations) of serum PFOS and PFOA were 31.6 (1.7) ng/mL and 9.17 (1.72) ng/mL, respectively. Multivariable linear regression analyses indicated that one interquartile range difference in PFOS corresponded to 4% and 9% increases in fT4 and T4 respectively. We detected statistical interactions between PFOA and age for effects on fT4 and T4; joint increases in PFOA and age were associated with increases in fT4 and T4, of 3% and 7%, respectively. We also detected statistical interactions between PFOS and total PCBs for the effect on T3 and between PFOA and total PBDEs for the effect on TSH. Our results suggest that PFASs are associated with subtle alterations in thyroid hormone levels in this population, and that these associations are likely to vary by age, and levels of PCBs and PBDEs.     

Perfluoroalkyl substances and food allergies in adolescents

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a class of organic compounds that are persistent in the environment due to their stable carbon-fluorine backbone, which is not susceptible to degradation. Research suggests these chemicals may exert an immunotoxic effect. The aim of this study is to investigate the associations between four PFASs – perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) – with food sensitization and food allergies in adolescent participants (ages 12–19 years) in the National Health and Nutrition Examination Survey (NHANES) 2005–2006 and 2007–2010, respectively. We performed multivariate logistic regression to analyze the association between individual PFASs with food sensitization (defined as having at least 1 food-specific IgE level ≥ 0.35 kU/L) in NHANES 2005–2006 and food allergies (self-reported) in NHANES 2007–2010. Serum PFOA, PFOS, and PFHxS were statistically significantly associated with higher odds to have self-reported food allergies in NHANES 2007–2010. When using IgE levels as a marker of food sensitization, we found that serum PFNA was inversely associated with food sensitization (NHANES 2005–2006). In conclusion, we found that serum levels of PFASs were associated with higher odds to have self-reported food allergies. Conversely, adolescents with higher serum PFNA were less likely to be sensitized to food allergens. These results, along with previous studies, warrant further investigation, such as well-designed longitudinal studies.     

Perfluoroalkyl substances in human milk: A first survey in Italy

Due to their widespread diffusion, perfluoroalkyl substances (PFASs) have been frequently found in the environment and in several animal species. It has been demonstrated that they can easily reach also humans, mainly through diet. Being lactation a major route of elimination of these contaminants, their occurrence in human milk is of particular interest, especially considering that it generally represents the unique food source for newborns. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), the two most important compounds of this family, have been frequently found in human milk at variable concentrations, but still limited data are available. The present study, the first conducted in Italy capable to detect these pollutants at ultra-trace levels by UPLC-MS/MS, confirmed the role of lactation as a relevant source of exposure for breastfed children. The measured concentrations ranged between 15 and 288 ng/L for PFOS and between 24 and 241 ng/L for PFOA. Moreover, mean concentrations and frequencies of both analytes resulted higher in milk samples provided by primiparous women, suggesting that the risk of intake might be higher for first-borns. Finally, comparing these results with previous data, PFOS gradual decrease over time since year 2000 was confirmed.     

Cumulative health risk assessment of 17 perfluoroalkylated and polyfluoroalkylated substances (PFASs) in the Swedish population

Humans are simultaneously exposed to a multitude of chemicals. Human health risk assessment of chemicals is, however, normally performed on single substances, which may underestimate the total risk, thus bringing a need for reliable methods to assess the risk of combined exposure to multiple chemicals. Per- and polyfluoroalkylated substances (PFASs) is a large group of chemicals that has emerged as global environmental contaminants. In the Swedish population, 17 PFASs have been measured, of which the vast majority lacks human health risk assessment information. The objective of this study was to for the first time perform a cumulative health risk assessment of the 17 PFASs measured in the Swedish population, individually and in combination, using the Hazard Index (HI) approach. Swedish biomonitoring data (blood/serum concentrations of PFASs) were used and two study populations identified: 1) the general population exposed indirectly via the environment and 2) occupationally exposed professional ski waxers. Hazard data used were publicly available toxicity data for hepatotoxicity and reproductive toxicity as well as other more sensitive toxic effects. The results showed that PFASs concentrations were in the low ng/ml serum range in the general population, reaching high ng/ml and low μg/ml serum concentrations in the occupationally exposed. For those congeners lacking toxicity data with regard to hepatotoxicity and reproductive toxicity read-across extrapolations was performed. Other effects at lower dose levels were observed for some well-studied congeners. The risk characterization showed no concern for hepatotoxicity or reproductive toxicity in the general population except in a subpopulation eating PFOS-contaminated fish, illustrating that high local exposure may be of concern. For the occupationally exposed there was concern for hepatotoxicity by PFOA and all congeners in combination as well as for reproductive toxicity by all congeners in combination, thus a need for reduced exposure was identified. Concern for immunotoxicity by PFOS and for disrupted mammary gland development by PFOA was identified in both study populations as well as a need of additional toxicological data for many PFAS congeners with respect to all assessed endpoints.     

Hazard quotient profiles used as a risk assessment tool for PFOS and PFOA serum levels in three distinctive European populations

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) blood levels are commonly used as biomarkers of human environmental exposure to these compounds. Many biomonitoring studies indicate 100% detection for PFOS and PFOA thus justifying a concern of possible risk for the most exposed individuals.This study addresses the predictive value of hazard quotients (HQs) calculated on the basis of serum PFOS and PFOA in male and female populations of reproductive age in Greenland, Poland and Ukraine.Overall, 2026 results of PFOS and PFOA serum concentrations (589 males, 1437 females) were obtained from the INUENDO database. HQs were calculated from the actual biomonitoring results and literature-based animal data linking toxicological outcomes and critical PFOS/PFOA serum levels. HQs for serum PFOS were calculated based on Points of Departure (PoD) at 13 μg mL^− 1 (cynomolgus monkeys, 183 days, changes in THS and T₃) and for PFOA at 7.1 μg mL^− 1 serum (male rats, 90 days, hepatocellular necrosis, increased liver weight). Uncertainty factors were applied to reflect interspecies differences and human variability. Serum HQs were expressed as a ratio relative to the point of departure for each PFOS and PFOA. Only in the three cases of males in Greenland were there serum PFOS levels showing HQ values exceeding 1, so indicating that such serum levels may be of concern. The mean serum concentration of PFOS was significantly higher in male than in female populations. Despite significant differences between HQ profiles for PFOS and PFOA in donors from Greenland, Poland and Ukraine, the concentrations of these perfluoroalkylated compounds do not indicate a cause for concern, except for the three aforementioned cases from Greenland.This study demonstrates that the HQ approach can help to interpret human biomonitoring data and thus serve as a valuable tool in further risk assessment priority settings and may also be used as a basis for taking decisions in risk management.     

Perfluoroalkyl acids in subarctic wild male mink (Neovison vison) in relation to age,season and geographical area

This study investigates the influence of biological and environmental factors on the concentrations of perfluoroalkyl acids (PFAAs) in a top predator; the American mink. Perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) with C₈–C₁₃ perfluorinated carbon chains were analyzed in livers from wild male mink liver (n = 101) from four areas in Sweden representing two inland environments (rural and highly anthropogenic, respectively) and two different coastal environments. Mean PFOS concentrations were 1250 ng/g wet weight and some mink from the urban inland area had among the highest PFOS concentrations ever recorded in mink (up to 21 800 ng/g wet weight). PFBS was detected in 89% of the samples, but in low concentrations (mean 0.6 ng/g ww). There were significant differences in PFAA concentrations between the geographical areas (p < 0.001–0.01). Age, body condition and body weight did not influence the concentrations significantly, but there was a seasonal influence on the concentrations of perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnDA) (p < 0.01 and p < 0.05, respectively), with lower concentrations in autumn samples than in samples taken in the winter and spring. It is thus recommended to take possible seasonal differences into account when using mink exposure data. The overall results suggest that the mink is a suitable sentinel species for assessing and monitoring environmental levels of PFAAs.     

Changes in serum levels of perfluoroalkyl substances during a 10-year follow-up period in a large population-based cohort

Poly- and perfluoroalkyl substances (PFASs) are a group of man-made fluorinated chemicals which have, at background levels, been associated with negative health effects in humans. Thus far, most human biomonitoring studies have evaluated the general change in PFAS concentration over time by continuously testing various individuals. This is one of the few studies to report the longitudinal trend of a range of PFAS concentrations in humans. In addition, this is the first known longitudinal study to include a large background level exposed cohort of both men and women with the same age and location who were repeatedly sampled from 2001 to 2014.The longitudinal change in concentration of eight PFASs detected in serum collected from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort were determined and compared to results from general population studies. The sex-dependent changes in PFAS concentrations over time were also assessed.Serum was sampled from the same individuals at ages 70 (collection period 2001–2004), 75 (2006–2009) and 80 (2011–2014,). Eight (C_6–11) of fourteen (C_4–13) analyzed PFASs were usually detected in over 75% of individuals and assessed using a random effects (mixed) model.In the 579 individuals attending all three examinations, PFOSA and PFOS concentrations significantly decreased, while the remaining six PFASs significantly increased between ages 70 and 75. However, between ages 75 and 80 all PFAS concentrations significantly decreased. Overall from age 70 to 80, concentrations of PFHxS, PFUnDA, PFNA, and PFDA showed a significant increase (7% to 34%), whereas concentrations of PFOSA, PFHpA, PFOS, and PFOA (− 75% to − 27%) significantly decreased. Over time PFHxS concentrations increased more among women, while PFHpA concentrations showed a greater decrease among men.From age 70 to age 80, spanning from 2001‐2004 to 2011–2014, the PIVUS cohort showed decreases in circulating levels of some PFASs phased out of production with the exception of PFHxS and C_>8 PFASs. Contrary to other studies, PFHxS concentrations showed the greatest overall increase, which is likely attributed to a local drinking water contamination incident.     

Perfluoroalkyl and polyfluoroalkyl substances in cord blood of newborns in Shanghai,China: Implications for risk assessment

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are commonly used in industrial applications and consumer products, and their potential health impacts are of concern, especially for vulnerable population like fetuses. However, in utero exposure to PFASs and health implications are far from fully characterized in China. To fill in the gap, we analyzed 10 PFASs in cord plasma samples (N = 687) collected in Shanghai between 2011 and 2012, one of the regions widely polluted with PFASs in China. A questionnaire survey on maternal and diet-related factors was conducted. Except for perfluoroheptanoic acid (PFHpA) and perfluorooctane sulfonamide (PFOSA), all other PFASs were detected in ˃90% of the samples. Perfluorooctanoic acid (PFOA) was the most predominant PFAS (median value: 6.96 ng/mL), followed by perfluorooctane sulfonate (PFOS) (2.48 ng/mL). PFOA and PFOS combined contributed to 80% of the total PFASs. The final multiple regression models showed that maternal factors including maternal age, body mass index, gestational age, economic status and educational level as well as consumption of fish and wheat were significantly related with concentrations of PFASs in cord blood. The risk assessment using the hazard quotients (HQs) approach on the basis of plasma PFAS levels indicated no potential concern for developmental toxicity in the local newborns. The results demonstrate the unique profiles of local prenatal exposure to PFASs, suggesting that PFOA has been the primary human exposure due to its widespread use and pollution. Special attention to high PFOA exposure and confirmation of potential determinants should be taken as a priority in the future plan for risk management and actions in this area.     

PFOS levels in the blood and liver of a small insectivorous songbird near a fluorochemical plant

Perfluorooctane sulfonate (PFOS) is the stable end product of the degradation of various perfluorinated compounds and is the predominant compound found in the environment and biota. PFOS is a widespread environmental contaminant that is found in a great diversity of wildlife species with more elevated tissue concentrations in animals from populated and industrialized areas. In this study we determined the PFOS accumulation in blood and livers of a small songbird, the great tit (Parus major), in the vicinity of a large fluorochemical plant in Antwerp, Belgium. PFOS concentrations ranged from 553 ng/g to 11359 ng/g in liver and ranged from 24 to 1625 ng/ml in blood, which are among the highest ever reported in free-living animals, and exceeded in almost all birds the hepatic benchmark concentrations for the protection of avian species [Beach SA, Newsted JL, Coady K, Giesy JP. Ecotoxicological evaluation of perfluorooctanesulfonate (PFOS). Rev Environ Contam Toxicol 2006;186:133-174]. Although PFOS concentrations in liver and blood decreased significantly within approximately 5.5 km of the plant, differences were smaller than previously described for wood mice (Apodemus sylvaticus) and nestling great tits. PFOS concentrations in liver and blood were higher in young birds (one-year old). No significant sex differences were found. A highly significant correlation between liver and blood concentrations indicates the usefulness of blood as a non-destructive matrix for biomonitoring purposes.     

The occurrence of perfluorinated alkyl compounds in human milk from different regions of China

Perfluorinated compounds (PFCs), especially perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA), are known to occur throughout the environment and in the human population (Houde et al., 2006). The occurrence of PFCs in human umbilical cord blood and human milk, coupled with the potential developmental toxicity of PFCs, suggests the need for determining the exposure sources and magnitudes of PFCs in infants. In this study, 10 PFCs were measured in 24 pooled samples consisting of 1237 individual human milk samples. The samples were collected from 12 provinces of China in 2007. PFOS and PFOA were the predominant PFCs found in all the samples tested. The geometric mean (GM) and median of the concentrations were 46 pg/mL and 49 pg/mL for PFOS, 46 pg/mL and 34.5 pg/mL for PFOA respectively. A large variation in geographical distribution was observed for PFCs in human milk. High concentrations of PFOA (814 pg/ml for the rural samples and 616 pg/ml for the urban samples) were found in human milk from Shanghai. Estimated dietary intakes (EDI) were established and the median, GM and the highest EDI of the total PFCs were 17.2 ng/kg/d, 17.8 ng/kg/d and 129.1 ng/kg/d respectively. The EDI for PFOA (88.4 ng/kg/d) for Shanghai was close to the tolerable daily intake (100 ng/kg/d) proposed by the German Federal Institute for Risk Assessment and the Drinking Water Commission. The results suggest both mothers and infants have a high exposure to PFCs in the Shanghai region. The potential health impact of postnatal exposure through breastfeeding to infants should therefore be comprehensively evaluated.     

Perfluorinated compounds in surface waters from Northern China: Comparison to level of industrialization

Inclusion of Perfluorooctane Sulfonate (PFOS) in the Stockholm Convention because of its exemptions, has resulted in increased annual production of PFOS-containing chemicals in China to accommodate domestic and overseas demands. Accordingly, concern about environmental contamination with perfluorinated compounds (PFCs), such as PFOS, has arisen. However, little information is available on the status and trends in the distribution, sources or risk of PFCs in aquatic environments of China. In the present study, forty two surface water samples collected from five regions with different levels of industrialization were monitored for concentrations of PFCs by use of solid phase extraction and LC/MS/MS. Mean concentrations (maximum concentration) of PFOA and PFOS, which were the dominant PFCs, were 1.2 (2.3) and 0.16 (0.52) ng/l for Guanting, 1.2 (1.8) and 0.32 (1.1) ng/l for Hohhot, 2.7 (15) and 0.93 (5.7) ng/l for Shanxi, 6.8 (12) and 2.6 (11) ng/l for Tianjin, 27 (82) and 4.7 (31) ng/l for Liaoning, respectively. The greatest concentrations of PFCs (121 ng/l), PFOA (82 ng/l) and PFOS (31 ng/l) were observed in Liaoning, which might originate from tributaries of the Liaohe River, the most polluted watershed in Northeast China. While, concentrations of PFCs in the Guanting and Hohhot regions were 3 to 20 fold less than those from Tianjin and Liaoning. This result is consistent with little contribution of PFCs being released from agricultural and non-industrial activities. The magnitudes of mass flow for PFOA and PFOS in decreasing order were: Guanting < Hohhot < Tianjin < Liaoning < Shanxi and Guanting < Hohhot < Shanxi < Tianjin < Liaoning. The larger mass flows of PFOS were accompanied by relatively larger magnitudes of PFOA. Concentrations of both PFOA and PFOS in waters from all regions were less than suggested allowable concentrations. However, the relatively greater concentrations of PFCs in Tianjin and Liaoning suggest that further studies characterizing their sources and potential risk to both humans and wildlife are needed.