Cooking decreases observed perfluorinated compound concentrations in fish

Per- and polyfluoroalkyl substances (PFAS) and hypertensive disorders of Pregnancy- integration of epidemiological and mechanistic evidence

BACKGROUND

Hypertensive disorders of pregnancy (HDP) remain a significant global health burden despite medical advancements. HDP prevalence appears to be rising, leading to increased maternal and fetal complications, mortality, and substantial healthcare costs. The etiology of HDP are complex and multifaceted, influenced by factors like nutrition, obesity, stress, metabolic disorders, and genetics. Emerging evidence suggests environmental pollutants, particularly Per- and polyfluoroalkyl substances (PFAS), may contribute to HDP development.

OBJECTIVE

This review integrates epidemiological and mechanistic data to explore the intricate relationship between PFAS exposure and HDP.

EPIDEMIOLOGICAL EVIDENCE

Studies show varying degrees of association between PFAS exposure and HDP, with some demonstrating positive correlations, particularly with preeclampsia. Meta-analyses suggest potential fetal sex-specific differences in these associations.

MECHANISTIC INSIGHTS

Mechanistically, PFAS exposure appears to disrupt vascular hemodynamics, placental development, and critical processes like angiogenesis and sex steroid regulation. Experimental studies reveal alterations in the renin-angiotensin system, trophoblast invasion, oxidative stress, inflammation, and hormonal dysregulation - all of which contribute to HDP pathogenesis. Elucidating these mechanisms is crucial for developing preventive strategies.

THERAPEUTIC POTENTIAL

Targeted interventions such as AT2R agonists, caspase inhibitors, and modulation of specific microRNAs show promise in mitigating adverse outcomes associated with PFAS exposure during pregnancy.

KNOWLEDGE GAPS AND FUTURE DIRECTIONS

Further research is needed to comprehensively understand the full spectrum of PFAS-induced placental alterations and their long-term implications for maternal and fetal health. This knowledge will be instrumental in developing effective preventive and therapeutic strategies for HDP in a changing environmental landscape.

Advances in perfluoro-alkylated compounds (PFAS) detection in seafood and marine environments: A comprehensive review on analytical techniques and global regulations

Per- and poly-fluoroalkyl substances (PFAS) are persistent organic pollutants that severely threaten the environment and human health due to their distinct chemical composition, extensive production, widespread distribution, bioaccumulation in nature, and long-term persistence. This review focuses on the occurrence and sources of PFAS in seafood, with a particular emphasis on advanced detection methods viz. nanoparticle-based, biosensor-based, and metal-organic frameworks-based, and mass spectrometric techniques. The challenges associated with these advanced detection technologies are also discussed. Recent research and regulatory updates about PFAS, including hazardous and potential health effects, epidemiological studies, and various risk assessment models, have been reviewed. In addition, the need for global monitoring programs and regulations on PFAS are critically reviewed by underscoring their crucial role in protecting human health and the environment. Further, approaches for reducing PFAS in seafood are highlighted with future innovative remediation directions. Although advanced PFAS analytical methods are available, selectivity, sample preparation, and sensitivity are still significant challenges associated with detection of PFAS in seafood matrices.  Moreover, crucial research gaps and solutions to essential concerns are critically explored in this review.

Epidemic-specific association of maternal exposure to per- and polyfluoroalkyl substances (PFAS) and their components with maternal glucose metabolism: A cross-sectional analysis in a birth cohort from Hong Kong

Per- and polyfluoroalkyl substances (PFAS) are persistent chemicals that have been linked to increased risk of gestational diabetes mellitus (GDM) and may affect glucose metabolisms during pregnancy. We examined the associations between maternal PFAS exposure and maternal glucose metabolisms and GDM risk among 1601 mothers who joined the Hyperglycaemia-and-Adverse-Pregnancy-Outcome (HAPO) Study in Hong Kong in 2001-2006. All mothers underwent a 75 g-oral-glucose-tolerance test at 24-32 weeks of gestation. We measured serum concentrations of six PFAS biomarkers using high-performance liquid-chromatography-coupled-with-tandem-mass-spectrometry (LC-MS-MS). We fitted conventional and advanced models (quantile-g-computation [qgcomp] and Bayesian-kernel machine regression [BKMR]) to assess the associations of individual and a mixture of PFAS with glycaemic traits. Subgroup analyses were performed based on the enrollment period by the severe-acute-respiratory-syndrome (SARS) epidemic periods in Hong Kong between March 2003 and May 2004. PFOS and PFOA were the main components of PFAS mixture among 1601 pregnant women in the Hong Kong HAPO study, with significantly higher median PFOS concentrations (19.09 ng/mL), compared to Chinese pregnant women (9.40 ng/mL) and US women (5.27 ng/mL). Maternal exposure to PFAS mixture was associated with higher HbA1c in the qgcomp (β = 0.04, 95 % CI: 0.01-0.06) model. We did not observe significant associations of PFAS mixture with fasting plasma glucose (PG), 1-h and 2-h PG in either model, except for 2-h PG in the qgcmop model (β = 0.074, 95 % CI: 0.01-0.15). PFOS was the primary contributor to the overall positive effects on HbA1c. Epidemic-specific analyses showed specific associations between PFAS exposure and the odds of GDM in the pre-SARS epidemic period. The median concentration of PFOS was highest during the peri-SARS epidemic (21.2 [14.5-43.6] ng/mL) compared with the pre-SARS (12.3 [9.2-19.9] ng/mL) and post-SARS (20.3 [14.2-46.3] ng/mL) epidemic periods. Potential interactions and exposure-response relationships between PFOA and PFNA with elevated HbA1c were observed in the peri-SARS period in BKMR model. Maternal exposure to PFAS mixture was associated with altered glucose metabolism during pregnancy. SARS epidemic-specific associations call for further studies on its long-term adverse health effects, especially potential modified associations by lifestyle changes during the COVID-19 pandemic.

Evaluation of fatty acids and carnitine as biomarkers of PFOS exposure in biota (fish and dolphin) from Galveston Bay and the northwestern Gulf of Mexico

Perfluorooctane sulfonate (PFOS) is a ubiquitous pollutant that elicits a wide range of toxic effects in exposed biota. Coastal zones in highly urbanized or industrial areas are particularly vulnerable to PFOS pollution. At present, information is lacking on biomarkers to assess PFOS effects on aquatic wildlife. This study investigated the efficacy of l-carnitine (or carnitine) and fatty acids as biomarkers of PFOS exposure in aquatic biota. The levels of PFOS, total and free carnitine, and 24 fatty acids (measured as fatty acid methyl esters or FAMEs) were measured in the liver, and muscle or blubber, of fish and dolphins sampled from Galveston Bay and the northern Gulf of Mexico (nGoM). Overall, bottlenose dolphins (Tursiops truncatus) had the highest hepatic PFOS levels. Galveston Bay fish, gafftopsail catfish (Bagre marinus), red drum (Sciaenops ocellatus), and spotted seatrout (Cynoscion nebulosus), had hepatic PFOS levels ∼8-13× higher than nGoM pelagic fish species, red snapper (Lutjanus campechanus) and yellowfin tuna (Thunnus albacares). The multivariate analysis of PFOS liver body-burdens and biomarkers found carnitine to be a more modal biomarker of PFOS exposure than FAMEs. Significant positive correlation of hepatic PFOS levels with total carnitine was evident for biota from Galveston Bay (fish only), and a significant correlation between PFOS and total and free carnitine was evident for biota from the nGoM (fish and dolphins). Given the essential role of carnitine in mediating fatty acid β-oxidation, our results suggest carnitine to be a likely candidate biomarker of environmental PFOS exposure and indicative of potential dyslipidemia effects.

Bioaccumulation and risk mitigation of legacy and novel perfluoroalkyl substances in seafood: Insights from trophic transfer and cooking method

Per- and polyfluoroalkyl substances (PFAS) have widespread application in industrial and civil areas due to their unique physical and chemical properties. With the increasingly stringent regulations of legacy PFAS, various novel alternatives have been developed and applied to meet the market demand. Legacy and novel PFAS pose potential threats to the ecological safety of coastal areas, however, little is known about their accumulation and transfer mechanism, especially after cooking treatment. This study investigated the biomagnification and trophic transfer characteristics of PFAS in seafood from the South China Sea, and assessed their health risks after cooking. Fifteen target PFAS were all detected in the samples, of which perfluorobutanoic acid (PFBA) was dominant with concentrations ranging from 0.76 to 4.12 ng/g ww. Trophic magnification factors (TMFs) > 1 were observed for perfluorooctane sulfonate (PFOS) and 6:2 chlorinated polyfluoroalkyl ether sulfonic acid (F-53B), indicating that these compounds experienced trophic magnification in the food web. The effects of different cooking styles on PFAS occurrence were further explored and the results suggested that ΣPFAS concentrations increased in most organisms after baking, while ΣPFAS amounts decreased basically after boiling and frying. Generally, there is a low health risk of exposure to PFAS when cooked seafood is consumed. This work provided quantitative evidence that cooking methods altered PFAS in seafood. Further, suggestions to mitigate the health risks of consuming PFAS-contaminated seafood were provided.

Dietary and maternal sociodemographic determinants of perfluoroalkyl and polyfluoroalkyl substance levels in pregnant women

Diet, including drinking water, and demographic characteristics have been associated with PFAS exposure levels in the general population. But data in pregnant women are scarce. We aimed to examine the PFAS levels in relation to these factors in early pregnancy and included 2545 pregnant women in early pregnancy from the Shanghai Birth Cohort. Ten PFAS were measured using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS-MS) in plasma samples at around 14 weeks of gestation. Geometric mean (GM) ratios were used to estimate the associations between demographic characteristics, food intake and source of drinking water and concentrations of nine PFAS with a detection rate of at least 70%, and the total perfluoroalkyl carboxylic acids (∑PFCA), perfluoroalkyl sulfonic acids (∑PFSA) and all the PFAS concentrations (∑PFAS). Median concentrations of plasma PFAS ranged from 0.03 ng/mL for PFBS to 11.56 ng/mL for PFOA. In the multivariable linear models, maternal age, parity, parental education level, marine fish, freshwater fish, shellfish, shrimps, crabs, animal kidneys, animal liver, eggs, and bone soup in early pregnancy were positively associated with plasma concentrations of certain PFAS. Whereas pre-pregnancy BMI, plant-based foods, and drinking bottled water were negatively associated with some PFAS concentrations. In summary, this study suggested that fish and seafood, animal offal, and high-fat foods (eggs and bone soup) were significant sources of PFAS. PFAS exposure may be reduced by consuming more plant-based foods and potential interventions, such as drinking water treatment.

Nonlethal detection of PFAS bioaccumulation and biomagnification within fishes in an urban- and wastewater-dominant Great Lakes watershed

Per- and polyfluoroalkyl substances (PFAS) are synthetic endocrine disruptors that are particularly stable and pervasive due to strong carbon-fluorine bonds. They are known to bioaccumulate in protein-rich tissues of fish, and most cannot be eliminated with cooking. Despite studies linking PFAS to adverse health outcomes, there is a lack of international regulations of PFAS as a hazardous material. To investigate PFAS in an aquatic food web and the potential human health implications, we analyzed the concentrations of 40 PFAS from muscle biopsy and serum samples of fish representing different trophic levels along the Lake Huron - Lake Erie Corridor. In Summer (2021), walleye (Sander vitreus; WAE), yellow perch (Perca flavescens; YEP) and round gobies (Neogobius melanostomus; ROG) were collected for analysis from the Detroit River (contaminated site) and St. Clair River (reference site). Eight PFAS congeners were detected in muscle and 15 congeners in serum, leading to the novel detection in Great Lakes fish of 7:3 FTCA in muscle and PFHpS, PFNS, MeFOSAA, and EtFOSAA in serum. PFOS was detected in 100% of muscle and serum pools across all species at concentrations lower than those associated with fish toxicity. Muscle PFOS concentration in DR WAE fell under the 8 meals per month (>13 ng-19 ng) fish consumption advisory according to the State of Michigan. Log bioaccumulation factor was significantly different (p = 0.01) among species in DR, driven by higher log BAF for WAE (3.8 ± 0.1) compared to ROG (3.2± 0.02). Biomagnification factor greater than 1 for all species in both rivers indicates that PFOS is biomagnifying in SCR and DR food webs. Successful detection and quantification of PFAS in the muscle and serum of three fish species demonstrates the potential for using this nonlethal sampling method to monitor PFAS and better understand ecological and human health impacts of PFAS exposure.

Exposure and Health Risk Assessment of Per- and Polyfluoroalkyl Substances in Crayfish from the Middle and Lower Reaches of the Yangtze River

Per- and polyfluoroalkyl substances (PFASs) are a novel class of emerging persistent organic pollutants (POPs) owing to their environmental persistence and bioaccumulation. Red swamp crayfish is a major source of exposure to PFASs, while the dietary intake of PFASs from crayfish is still unclear. We investigated the concentrations of PFASs in 130 batches of crayfish and 100 environmental samples from Middle and Lower Reaches of the Yangtze River Delta. Seven Perfluoroalkyl carboxylic acids (PFCAs), 3 Perfluoroalkyl sulfonates (PFSAs), and 6:2 Cl-PFESA were analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Meanwhile, PFASs exposure levels were examined concretely in four tissues of crayfish and different circulation links. The average daily intake (ADI) risk model was used to evaluate the human health risk of consuming crayfish and suggested that the risk of PFASs exposure is at a low level.

Thermal processing reduces PFAS concentrations in blue food - A systematic review and meta-analysis

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in the environment and often ingested with food. PFAS exposure in people can have detrimental health consequences. Therefore, reducing PFAS burdens in food items is of great importance to public health. Here, we investigated whether cooking reduces PFAS concentrations in animal-derived food products by synthesizing experimental studies. Further, we examined the moderating effects of the following five variables: cooking time, liquid/animal tissue ratio, cooking temperature, carbon chain length of PFAS and the cooking category (oil-based, water-based & no-liquid cooking). In our systematic review searches, we obtained 512 effect sizes (relative differences in PFAS concentration between raw and cooked samples) from 10 relevant studies. These studies exclusively explored changes in PFAS concentrations in cooked seafood and freshwater fish. Our multilevel-meta-analysis has revealed that, on average, cooking reduced PFAS concentrations by 29%, although heterogeneity among effect sizes was very high (I² = 94.65%). Our five moderators cumulatively explained 49% of the observed heterogeneity. Specifically, an increase in cooking time and liquid/animal tissue ratio, as well as shorter carbon chain length of PFAS (when cooked with oil) were associated with significant reductions in PFAS concentrations. The effects of different ways of cooking depended on the other moderators, while the effect of cooking temperature itself was not significant. Overall, cooking can reduce PFAS concentrations in blue food (seafood and freshwater fish). However, it is important to note that complete PFAS elimination requires unrealistically long cooking times and large liquid/animal tissue ratios. Currently, literature on the impact of cooking of terrestrial animal produce on PFAS concentrations is lacking, which limits the inference and generalisation of our meta-analysis. However, our work represents the first step towards developing guidelines to reduce PFAS in food via cooking exclusively with common kitchen items and techniques.

Perfluoroalkyl Substances in U.S. market basket fish and shellfish

Over the past two decades the class of per- and polyfluoroalkyl substances (PFAS) has emerged as a widespread contaminant in environmental media globally. As awareness and understanding of its prevalence, persistence, and potential health risks grows, so have concerns about human exposure. While drinking water has received substantial attention, dietary intakes have also been reported to contribute significantly to total exposure, with fish consumption in particular. Most studies of U.S. fish have targeted sport fish from areas of known or suspected contamination. This study was undertaken to improve data on PFAS levels in the U.S. commercial seafood supply. A total of 70 samples of finfish and shellfish were purchased at U.S. grocery stores and fish markets and analyzed for 26 PFAS compounds. The samples included a range of marine and freshwater species from four regions of the U.S. and seven countries with significant imports to the U.S. Up to ten PFAS were detected in 21 samples, with PFOS the predominant compound. There were no detections in the remaining 49 samples (detection limits of approximately 0.4-0.5 ppb). Total PFAS concentrations in most samples were single digit or sub-ppb levels. The exception was commercial finfish from the Great Lakes area, for which higher levels (up to 22 ppb) were observed in whitefish, walleye, and yellow perch fillet. Study findings suggest PFAS is present at low or non-detect levels in the U.S. commercial seafood supply and exposure is low for consumers of market basket fish and shellfish.

Cooking methods affect the intake of per- and polyfluoroalkyl substances (PFASs) from grass carp

Consumption of fish is one of the predominant sources of human exposure to per- and polyfluoroalkyl substances (PFASs). In this study, the effect of various cooking methods (boiling, steaming, grilling and frying) on the levels of PFASs in fish muscle and the intake of PFASs was explored by using grass carp collected from Tangxun Lake, Wuhan, China. Perfluorooctane sulfonate (PFOS) was the predominant PFASs in raw fish fillets, with the concentrations ranging from 59.6 to 136 ng/g ww, followed by perfluorobutane sulfonate (PFBS) (7.73-51.9 ng/g ww). The concentrations of long-chain PFASs in fish increased after cooking, while those of short-chain PFASs decreased. The amounts of PFASs in the cooked fish fillets decreased except PFOS. Short-chain PFASs, including PFBS and perfluoroheptanoic acid (PFHpA), were dominant in cooking juice. The highest amounts of PFBS in the juices were observed after boiling and frying, even higher than those in cooked fish fillets, suggesting that the release of short-chain PFASs to the cooking juices could not be neglected. Based on these results, the intake of short-chain PFASs amount through cooked fish fillets slightly decreased, but the intake of PFOS amount increased. However, consumption of cooking juice (fish soup) could increase the exposure risk of PFBS. Comprehensively considering the increase of PFOS and decrease of total PFASs, boiling may be the relatively better method to cook fish. As PFASs are ubiquitous and inevitable in aquatic food, it is thus important to choose appropriate cooking processes and dietary habits for reducing the intake of different PFASs from fish.

Environmental levels and human body burdens of per- and poly-fluoroalkyl substances in Africa: A critical review

Per- and polyfluoroalkyl substances (PFASs) are known organic pollutants with adverse health effects on humans and the ecosystem. This paper synthesises literature about the status of the pollutants and their precursors, identifies knowledge gaps and discusses future perspectives on the study of PFASs in Africa. Limited data on PFASs prevalence in Africa is available because there is limited capacity to monitor PFASs in African laboratories. The levels of PFASs in Africa are higher in samples from urban and industrialized areas compared to rural areas. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are the dominant PFASs in human samples from Africa. Levels of PFOS and PFOA in these samples are lower than or comparable to those from industrialized countries. PFOA and PFOS levels in drinking water in Africa are, in some cases, higher than the EPA drinking water guidelines suggesting potential risk to humans. The levels of PFASs in birds' eggs from South Africa are higher, while those in other environmental media from Africa are lower or comparable to those from industrialized countries. Diet influences the pollutant levels in fish, while size and sex affect their accumulation in crocodiles. No bioaccumulation of PFASs in aquatic systems in Africa could be confirmed due to small sample sizes. Reported sources of PFASs in Africa include municipal landfills, inefficient wastewater treatment plants, consumer products containing PFASs, industrial wastewater and urban runoff. Relevant stakeholders need to take serious action to identify and deal with the salient sources of PFASs on the African continent.

Effect of washing, soaking, and cooking methods on perfluorinated compounds in mackerel (Scomber japonicus)

Perfluorinated compounds (PFCs) are environmental pollutants, and dietary intake is a major route of human exposure to them. We aimed to see the effects of washing, soaking, and cooking (grilling, braising, frying, and steaming) on the change of PFCs in mackerel fillets and PFCs before and after each treatment were analyzed using LC-MS/MS. Washing resulted in a decrease in the PFC content of mackerel (average 74%) comparing to control. Among the 19 PFCs detected, perfluorobutanoic acid and perfluorotridecanoic acid (PFTrDA) were found to be abundant after washing. Soaking mackerel in sake reduced its PFC content by 51%, whereas soaking in rice-washed solution reduced by 80% comparing to control. All the four cooking methods were effective in reducing the PFC content of mackerel. The degree by which the PFC content decreased varied with the cooking method: grilling (91%), steaming (75%), frying (58%), and braising (47%) comparing to uncooked sample. In addition, when mackerel was braised with potato, PFCs decreased more in fillet than the ones without potato. PFCs in potato increased after cooking with mackerel. The excessive consumption through the mackerel was 0.1997 ng/kg bw/day and 0.7987 ng/kg bw/day, respectively. These exposure levels were well below the tolerable daily intake values of both compounds (PFOS, 150 ng/kg bw/day; PFOA, 1,500 ng/kg bw/day). The results of this study indicated that employing appropriate pretreatment and cooking methods could be an effective way to reduce the dietary exposure to PFCs in mackerel.

A Review of Perfluoroalkyl Acids (PFAAs) in terms of Sources, Applications, Human Exposure, Dietary Intake, Toxicity, Legal Regulation, and Methods of Determination

Per- and polyfluoroalkyl substances (PFASs) are widely distributed across the world and are expected to be of concern to human health and the environment. The review focuses on perfluoroalkyl acids (PFAAs) and, in particular, on the most frequently discussed perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs). In this study, some basic information concerning PFASs is reviewed, focusing mainly on PFAAs (perfluoroalkyl acids). We have made efforts to systemize their division into groups according to chemical structure, describe their basic physicochemical properties, characterize production technologies, and determine potential human exposure routes with particular reference to oral exposure. A variety of possible toxicological effects to human health are also discussed. In response to increasing public concern about the toxicity of PFAAs, an evaluation of dietary intake has been undertaken for two of the most commonly known PFAAs: perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). As summarized in this study, PFAAs levels need further assessment due to the science-based TWI standards laid down by the EFSA’s CONTAM Panel regarding the risk to human health posed by the presence of perfluorooctane sulfonic acid and perfluorooctanoic acid in food (tolerable weekly intakes of PFOA and PFOS set up to 6 ng·kg−1·bw·week−1 and 13 ng·kg−1·bw·week−1, respectively). Current legislation, relevant legislation on PFAAs levels in food, and the most popular methods of analysis in food matrices are described.

Assessment of individual-based perfluoroalkly substances exposure by multiple human exposure sources

Individual exposure of perfluoroalkyl substances (PFASs) was assessed by analyzing serum, food, dust, drinking water, and hand wipes from 50 individuals. The PFASs concentrations in serum were correlated most strongly with exposure to PFASs through the (direct and indirect) ingestion of dust (p <  0.01). Daily PFOA intakes were estimated to be 2.07 ng/kg/day from food, 0.003 ng/kg/day from dust, 0.053 ng/kg/day from hand-to-mouth activity, and 0.020 ng/kg/day from drinking water. Daily perfluorooctanesulfonic acid (PFOS) intakes were estimated to be 0.689 ng/kg/day from food, 0.001 ng/kg/day from dust, 0.018 ng/kg/day from hand-to-mouth activity, and 0.005 ng/kg/day from drinking water. The daily PFOA and PFOS intakes calculated for individuals in this study and in group/scenario based exposure assessment of previous studies were compared. The estimated PFOS intake on individual basis (0.695 ng/kg/day) was a little bit higher than the intake on group/scenario basis (0.652 ng/kg/day). However, the estimated daily PFOA intake on individual basis (1.41 ng/kg/day) was about four times higher than the intake on group/scenario basis (0.339 ng/kg/day). Among the exposure pathways, food ingestion was major contributor to the total daily PFOA and PFOS intakes on individuals (99% of total intake) and group/scenario basis (64% of total intake).

A review of the pathways of human exposure to poly- and perfluoroalkyl substances (PFASs) and present understanding of health effects

Here, we review present understanding of sources and trends in human exposure to poly- and perfluoroalkyl substances (PFASs) and epidemiologic evidence for impacts on cancer, immune function, metabolic outcomes, and neurodevelopment. More than 4000 PFASs have been manufactured by humans and hundreds have been detected in environmental samples. Direct exposures due to use in products can be quickly phased out by shifts in chemical production but exposures driven by PFAS accumulation in the ocean and marine food chains and contamination of groundwater persist over long timescales. Serum concentrations of legacy PFASs in humans are declining globally but total exposures to newer PFASs and precursor compounds have not been well characterized. Human exposures to legacy PFASs from seafood and drinking water are stable or increasing in many regions, suggesting observed declines reflect phase-outs in legacy PFAS use in consumer products. Many regions globally are continuing to discover PFAS contaminated sites from aqueous film forming foam (AFFF) use, particularly next to airports and military bases. Exposures from food packaging and indoor environments are uncertain due to a rapidly changing chemical landscape where legacy PFASs have been replaced by diverse precursors and custom molecules that are difficult to detect. Multiple studies find significant associations between PFAS exposure and adverse immune outcomes in children. Dyslipidemia is the strongest metabolic outcome associated with PFAS exposure. Evidence for cancer is limited to manufacturing locations with extremely high exposures and insufficient data are available to characterize impacts of PFAS exposures on neurodevelopment. Preliminary evidence suggests significant health effects associated with exposures to emerging PFASs. Lessons learned from legacy PFASs indicate that limited data should not be used as a justification to delay risk mitigation actions for replacement PFASs.

Risk to human health related to the presence of perfluorooctane sulfonic acid and perfluorooctanoic acid in food

The European Commission asked EFSA for a scientific evaluation on the risks to human health related to the presence of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in food. Regarding PFOS and PFOA occurrence, the final data set available for dietary exposure assessment contained a total of 20,019 analytical results (PFOS n = 10,191 and PFOA n = 9,828). There were large differences between upper and lower bound exposure due to analytical methods with insufficient sensitivity. The CONTAM Panel considered the lower bound estimates to be closer to true exposure levels. Important contributors to the lower bound mean chronic exposure were 'Fish and other seafood', 'Meat and meat products' and 'Eggs and egg products', for PFOS, and 'Milk and dairy products', 'Drinking water' and 'Fish and other seafood' for PFOA. PFOS and PFOA are readily absorbed in the gastrointestinal tract, excreted in urine and faeces, and do not undergo metabolism. Estimated human half-lives for PFOS and PFOA are about 5 years and 2-4 years, respectively. The derivation of a health-based guidance value was based on human epidemiological studies. For PFOS, the increase in serum total cholesterol in adults, and the decrease in antibody response at vaccination in children were identified as the critical effects. For PFOA, the increase in serum total cholesterol was the critical effect. Also reduced birth weight (for both compounds) and increased prevalence of high serum levels of the liver enzyme alanine aminotransferase (ALT) (for PFOA) were considered. After benchmark modelling of serum levels of PFOS and PFOA, and estimating the corresponding daily intakes, the CONTAM Panel established a tolerable weekly intake (TWI) of 13 ng/kg body weight (bw) per week for PFOS and 6 ng/kg bw per week for PFOA. For both compounds, exposure of a considerable proportion of the population exceeds the proposed TWIs.

Pharmaceuticals and endocrine disruptors in raw and cooked seafood from European market: Concentrations and human exposure levels

Pharmaceuticals (PhACs) and endocrine disrupting compounds (EDCs) are chemicals of emerging concern that can accumulate in seafood sold in markets. These compounds may represent a risk to consumers through effects on the human reproductive system, metabolic disorders, pathogenesis of breast cancer or development of microbial resistance. Measuring their levels in highly consumed seafood is important to assess the potential risks to human health. Besides, the effect of cooking on contaminant levels is relevant to investigate. Therefore, the objectives of this research were to study the presence and levels of PhACs and EDCs in commercially available seafood in the European Union market, to investigate the effect of cooking on contaminant levels, and to evaluate the dietary exposure of humans to these compounds through seafood consumption. A sampling survey of seafood from 11 European countries was undertaken. Twelve highly consumed seafood types were analysed raw and cooked with 3 analytical methods (65 samples, 195 analysis). PhACs were mostly not detectable or below quantification limits in seafood whereas EDCs were a recurrent group of contaminants quantified in the majority of the samples. Besides, cooking by steaming significantly increased their levels in seafood from 2 to 46-fold increase. Based on occurrence and levels, bisphenol A, methylparaben and triclosan were selected for performing a human exposure assessment and health risk characterisation through seafood consumption. The results indicate that the Spanish population has the highest exposure to the selected EDCs through seafood consumption, although the exposure via seafood remained below the current toxicological reference values.

Nutrients and Chemical Pollutants in Fish and Shellfish. Balancing Health Benefits and Risks of Regular Fish Consumption

Dietary patterns and lifestyle factors are clearly associated with at least five of the ten leading causes of death, including coronary heart disease, certain types of cancer, stroke, non-insulin insulin-dependent diabetes mellitus, and atherosclerosis. Concerning specifically fish and seafood consumption, its beneficial health effects in humans are clearly supported by an important number of studies performed in the last 30 years. These studies have repeatedly linked fish consumption, especially those species whose contents in omega-3 fatty acids are high, with healthier hearts in the aging population. The nutritional benefits of fish and seafood are also due to the content of high-quality protein, vitamins, as well as other essential nutrients. However, a number of studies, particularly investigations performed in recent years, have shown that the unavoidable presence of environmental contaminants in fish and shellfish can also mean a certain risk for the health of some consumers. While prestigious international associations as the American Heart Association have recommended eating fish at least two times (two servings a week), based on our own experimental results, as well as in results from other laboratories, we cannot be in total agreement with that recommendation. Although a regular consumption of most fish and shellfish species should not mean adverse health effects for the consumers, the specific fish and shellfish species consumed, the frequency of consumption, as well as the meal size, are essential issues for adequately balancing the health benefits and risks of regular fish consumption.

Levels of Contamination by Perfluoroalkyl Substances in Honey from Selected European Countries

Perfluoroalkyl substances (PFASs) are man-made chemicals manufactured for numerous applications. The aim of this study was to assess the levels of 10 PFASs in selected types of honey samples from selected eastern, northern and southern European countries. A total of 26 samples of honey were analyzed. PFCAs (perfluoroalkyl carboxylic acids) were detected in almost all (92 %) analyzed samples in the range of 0.124-0.798 ng g(-1) ww (wet weight). The average concentrations of particular PFCAs (ng g(-1) ww) in honey samples increased in the following order: perfluorononanoic acid (0.164) < perfluorooctanoic acid (0.189) < perfluoroheptanoic acid (0.271) < perfluorodecanoic acid (0.278). Amongst perfluoroalkane sulfonates, only perfluorohexane sulfonate (PFHxS) was identified in four of 26 analyzed samples, and its concentrations ranged from 0.080 to 0.191 ng g(-1) ww. Italian eucalyptus honey contained the highest total content of PFASs (0.878 ng g(-1) ww). Samples originating from an industrial region of Poland showed 20 % higher concentrations of PFCAs compared to those from non-industrial regions.

Levels of perfluorinated compounds in raw and cooked Mediterranean finfish and shellfish

Perfluorinated compounds (PFCs) were analyzed in several species of small Mediterranean fish and shellfish, all of which are popular in Greek diet. Analysis was conducted in raw samples and in samples cooked by the two ways preferred in Greek cuisine, i.e. fried in olive oil and grilled. PFCs above the detection limit were found in all raw samples except sardine, mussel and squid. The predominant PFC was PFOS (perfluorooctane sulfonate), the highest concentration of which was measured in picarel (20.4 ng g(-1) fresh weight). The PFOS values for the rest of the samples were between <LOD and 5.66 ng g(-1) fw. The concentrations of the detected PFCs were in most cases higher after frying or grilling, this increase being statistically significant. Based on these results, the Tolerable Daily Intake for PFOS and PFOA (perfluorooctanoic acid) through consumption of fish and seafood was well below the values proposed by EFSA.

Perfluorinated compounds in fish from U.S. urban rivers and the Great Lakes

Perfluorinated compounds (PFCs) have recently received scientific and regulatory attention due to their broad environmental distribution, persistence, bioaccumulative potential, and toxicity. Studies suggest that fish consumption may be a source of human exposure to perfluorooctane sulfonate (PFOS) or long-chain perfluorocarboxylic acids. Most PFC fish tissue literature focuses on marine fish and waters outside of the United States (U.S.). To broaden assessments in U.S. fish, a characterization of PFCs in freshwater fish was initiated on a national scale using an unequal probability design during the U.S. Environmental Protection Agency's (EPA's) 2008-2009 National Rivers and Streams Assessment (NRSA) and the Great Lakes Human Health Fish Tissue Study component of the 2010 EPA National Coastal Condition Assessment (NCCA/GL). Fish were collected from randomly selected locations--164 urban river sites and 157 nearshore Great Lake sites. The probability design allowed extrapolation to the sampled population of 17,059 km in urban rivers and a nearshore area of 11,091 km(2) in the Great Lakes. Fillets were analyzed for 13 PFCs using high-performance liquid chromatography tandem mass spectrometry. Results showed that PFOS dominated in frequency of occurrence, followed by three other longer-chain PFCs (perfluorodecanoic acid, perfluoroundecanoic acid, and perfluorododecanoic acid). Maximum PFOS concentrations were 127 and 80 ng/g in urban river samples and Great Lakes samples, respectively. The range of NRSA PFOS detections was similar to literature accounts from targeted riverine fish sampling. NCCA/GL PFOS levels were lower than those reported by other Great Lakes researchers, but generally higher than values in targeted inland lake studies. The probability design allowed development of cumulative distribution functions (CDFs) to quantify PFOS concentrations versus the sampled population, and the application of fish consumption advisory guidance to the CDFs resulted in an estimation of the proportion of urban rivers and the Great Lakes that exceed human health protection thresholds.

Food risk assessment for perfluoroalkyl acids and brominated flame retardants in the French population: results from the second French total diet study

To determine the exposure of the French population to toxic compounds contaminating the food chain, a total diet study was performed in France between 2007 and 2009. This study was designed to reflect the consumption habits of the French population and covered the most important foods in terms of consumption, selected nutrients and contribution to contamination. Based on French consumption data, the present study reports the dietary exposure to perfluoroalkyl acids (16 congeners) and brominated flame retardants (polybrominated diphenyl ethers, hexabromocyclododecane and polybrominated biphenyls). Comparison of the calculated dietary exposures with the generally accepted health-based guidance values revealed that most compounds do not pose any risk. There are however knowledge gaps for some congeners in these large chemical classes.

TDS exposure project: relevance of the total diet study approach for different groups of substances

A method to validate the relevance of the Total Diet Study (TDS) approach for different types of substances is described. As a first step, a list of >2800 chemicals classified into eight main groups of relevance for food safety (natural components, environmental contaminants, substances intentionally added to foods, residues, naturally occurring contaminants, process contaminants, contaminants from packaging and food contact materials, other substances) has been established. The appropriateness of the TDS approach for the different substance groups has then been considered with regard to the three essential principles of a TDS: representativeness of the whole diet, pooling of foods and food analyzed as consumed. Four criteria were considered for that purpose (i) the substance has to be present in a significant part of the diet or predominantly present in specific food groups, (ii) a robust analytical method has to be available to determine it in potential contributors to the dietary exposure of the population, and (iii) the dilution impact of pooling and (iv) the impact of everyday food preparation methods on the concentration of the substance are assessed. For most of the substances the TDS approach appeared to be relevant and any precautions to be taken are outlined.

Cooking fish is not effective in reducing exposure to perfluoroalkyl and polyfluoroalkyl substances

Consumption of fish is considered a part of a healthy diet; however, health risks from fish consumption exist due to potential exposure to various contaminants accumulated in fish. Cooking fish can reduce exposure to many organic chemicals in fish. Similar results have been presented for low levels of perfluoroalkyl and polyfluoroalkyl substances (PFASs), a class of contaminants of emerging concern, in grocery store fish. We examined the effectiveness of three cooking methods (i.e., baking, broiling, and frying) on reducing PFAS levels in four sport fish species. Samples of Chinook salmon, common carp, lake trout and walleye were collected from four rivers in Ontario, Canada and skin-off fillets were analyzed for regular groups of PFASs such as perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs), as well as perfluoroalkyl phosphonic acids (PFPAs), perfluoroalkyl phosphinic acids (PFPIAs) and polyfluoroalkyl phosphoric acid diesters (diPAPs), which are PFASs of emerging concern. Perfluorooctane sulfonate (PFOS) was the dominant PFAS detected and the concentrations were more than an order of magnitude higher than those reported for fish from grocery stores in Canada, Spain, and China. Although concentrations of PFOS in fish fillets generally increase after cooking, amounts of PFOS largely remain unchanged. Relatively minor differences in changes in the fish PFAS amounts after cooking depended on fish species and cooking method used. We conclude that cooking sport fish is generally not an effective approach to reduce dietary exposure to PFASs, especially PFOS.

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and perfluorinated alkylated substances (PFASs) in traditional seafood items from western Greenland

In this study, contamination levels were determined for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and perfluorinated alkylated substances (PFASs) in traditional Greenland seafood items, such as raw and smoked fish fillet (salmon and halibut), whale and seal meat and narwhal mattak (skin and blubber). The daily intake of PCBs, PBDEs and PFASs through traditional seafood items in Greenland was assessed. Based on the presented levels of contaminants, in combination with earlier food intake studies, suggests that the daily exposure was below the tolerable daily intake threshold for all compounds. BDE-47 was the only PBDE-congener detected in all food items, except in smoked halibut. The levels of BDE-47 varied from < LOD in smoked halibut up to 18 ng/g lw in narwhal mattak and 21 ng/g lw in whale beef. ∑PCB were lowest in smoked halibut (37 ng/g lw) and highest in narwhal mattak with 1,146 ng/g lw. Perfluorooctane sulfonate (PFOS) was the most common of the PFASs. However, ΣPFASs were below detection limits in most fish fillet samples, and varied from 2.9 ng/g ww in whale beef to 13.5 ng/g ww in seal beef. The present study shows that the exclusion from the diet of local food items such as intestines and blubber have a strong positive effect for the reduction of POPs levels in food, without a reducing the health benefits of traditional food intake considerably.

Determination of perfluorochemicals in fish and shellfish using liquid chromatography-tandem mass spectrometry

This paper reports the validation and application of a method for determination of 10 perfluorochemicals (PFCs) in retail fish and shellfish. The analytes of interest were 7 perfluorinated carboxylates and 3 perfluorinated sulfonates. Fish and shellfish samples were digested with a basic solution of 10 mM sodium hydroxide in methanol before sonication and solid phase extraction through weak anion exchange. Analysis was performed using liquid chromatography-tandem mass spectrometry. Recoveries from spiking five different types of fish and shellfish indicate that the method performs similarly with different fish types, and recoveries were over 90% for all analytes. Forty-six retail samples, collected between 2010 and 2012, including 13 different types of fish and shellfish were analyzed for PFCs. The 13 different types included the top 10 most-consumed fish and shellfish in the United States according to data collected by the National Fisheries Institute. Two Standard Reference Materials were also analyzed. Most fish and shellfish had no detected PFCs; only 11 samples of the 46 tested had detectable concentrations of PFCs.

Impact of industrial production and packaging processes on the concentration of per- and polyfluorinated compounds in milk and dairy products

Perfluorinated alkylated compounds (PFAA) have been identified in milk and dairy products at sub ppb levels, however, knowledge on the impact of industrial milk processing on PFAA levels is rare. This study examined industrial milk processing first by analytical screening of products of a cooperating dairy, which varied in kind and number of processing steps. Second, amounts of PFAA in raw milk, cream, skim milk, butter milk, and butter were mass balanced in industrial production. For migration testing, unpacked butter was sampled from the production and exposed to original packaging at 5 °C for 45 days. Screening identified dairy products with high fat contents to bear higher loads of PFAA. The mass balance of butter production revealed a significant impact of phase separation processes on concentrations in fat rich and aqueous phases. Storage of butter in packaging coated with a fluorinated polymer increased butter levels of both PFAA and FTOH.

Pilot study on levels of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in selected foodstuffs and human milk from Italy

Despite the health risks associated with perfluorinated compounds (PFC) exposure and the detection of these compounds in many countries around the world, little is known on their occurrence in Italy. The results of a study on levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), analysed by HPLC-ESI-MS, in human milk and food samples from the city of Siena and its province (central Italy) are here reported. PFOS was found in 13 out of 49 breast milk samples (0.76±1.27 ng/g), while PFOA was detected in one sample (8.04 ng/g). Only PFOS was found in food samples. Fish were the most contaminated samples (7.65±34.2 ng/g); mean concentrations in meat and milk and dairy products were similar (1.43±7.21 ng/g and 1.35±3.45 ng/g, respectively). In all cereal-based food, eggs, vegetables, honey and beverages PFOS concentration was <LOD. These data show that consumption of most breast milk analysed would not result in children exceeding their total daily intakes for perfluorinated compounds.

Impacts of cooking technique on polychlorinated biphenyl and polychlorinated dioxins/furan concentrations in fish and fish products with intake estimates

Polychlorinated biphenyl (PCB) and polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) concentrations were determined in composites of 18 different fish products and were prepared as raw, baked, boiled, and fried. ∑PCB concentrations were found to range from 0.12 ng·g(-1) whole weight (ww) in raw octopus to 33 ng·g(-1) ww in baked mackerel. Boiled monkfish was found to have the lowest ∑PCDD/F concentrations (0.41 pg·g(-1) ww), while maximum concentrations were observed in fried catfish (59 pg·g(-1) ww). PCB and PCDD/F concentrations in fish were generally reduced during cooking, although differences were small. The average PCB reduction in finfish was 7.9%, while an increase in PCB mass was observed in non-finfish (2.9%). PCDD/F losses, on average, were observed in both the finfish (3.6%) and non-finfish products (25%). Maximum ∑PCB, ∑PCDD/F, and TEQ(PCDD/F+DL-PCB) (toxic equivalency) intakes, based on 150 g serving size, were determined to be 3300 ng (mackerel), 6600 pg (catfish), and 270 pg (catfish), respectively. PCB and PCDD/F changes associated with cooking generally were small (<15%), although larger mean differences (∼40%) were observed in some fish products (e.g., catfish).

The associations between serum perfluorinated chemicals and thyroid function in adolescents and young adults

Perfluorinated chemicals (PFCs) have been widely used in a variety of products worldwide for years. However, the effect of PFCs on thyroid function has not yet been clearly defined. We recruited 567 subjects (aged 12-30 years) in a population-based cohort of adolescents and young adults with abnormal urinalysis in the childhood to determine the relationship between serum level of PFCs and the levels of serum free thyroxine (T4) and thyroid stimulating hormone (TSH). The geometric means and geometric standard deviation concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUA) were 2.67 (2.96) ng/ml, 7.78 (2.42) ng/ml, 1.01 (3.48) ng/ml and 5.81 (2.92) ng/ml, respectively. Differences in the levels of free T4 and TSH across different categories of PFOA, PFOS and PFUA were insignificant. After controlling for confounding factors, multiple linear regression analyses revealed mean serum level of free T4 increased significantly across categories (<60th, 60-89 and >90th percentiles) of PFNA (P for trend =0.012 in the full model). The association between PFNA and free T4 was more significant in male subjects in age group 20-30, active smokers and in those with higher body mass index in stratified analysis. Serum concentrations of PFNA were associated with serum free T4 levels in adolescents and young adults.

Perfluorinated compounds in seafood from coastal areas in China

Diet is an important source of perfluorinated compound (PFC) exposure and seafood is an important diet component for coastal populations. Therefore, it is necessary to monitor the concentrations of PFCs in seafood. In this study, we measured thirteen PFCs in 47 fatty fish and 45 shellfish samples collected from six coastal provinces in China (Liaoning, Shandong, Jiangsu, Zhejiang, Fujian, and Guangdong), using an ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). Perfluorooctanesulfonate (PFOS) was the dominant PFC in fatty fish which accounted for 38% of total PFCs, whereas perfluoroctanoic acid (PFOA) was the predominant PFC in shellfish. Concentrations of PFOS were ranged from less than 1.4 to 1627 pg/g wet weight in fatty fish, with the highest concentration in red drum from Jiangsu. Concentrations of PFOA in shellfish ranged from less than 5.4 to 7543 pg/g wet weight, with the maximum concentration found in briny clam also from Jiangsu. Compared with other studies, the PFC levels in seafood collected from our studied areas are relatively low. The estimated dietary intakes (EDI, pg/kg body weight /day) of PFOA, PFOS and total PFCs for the reference man (63 kg body weight) were calculated by multiplying the mean concentrations (pg/g wet weight) of PFOA, PFOS and total PFCs in six coastal provinces with the daily consumption data (g/day) from the fourth Chinese total diet study carried out in 2007. The highest EDI of PFOS and PFOA were found to be 694 pg/kg body weight/day and 914 pg/kg body weight/day in Guangdong and Jiangsu, respectively. However, the highest EDI of total PFCs was found in Fujian at 2513 pg/kg body weight/day. The EDI from seafood is much lower than the tolerable daily intake (TDI) recommended by the European Food Safety Authority in 2008 indicating low health risk of PFC exposure via eating seafood among the coastal populations in China.

Health risks of dietary exposure to perfluorinated compounds

Perfluorinated compounds (PFCs) form a diverse group of chemicals with surface-active properties manufactured for over 50 years. In recent years, a number of studies have reported the ubiquitous distribution of PFCs in human tissues and wildlife. Although the relative importance of the routes of human exposure to these compounds is not well established yet, it has been suggested that food intake and packaging, water, house dust, and airborne are all potentially significant sources. However, dietary intake is probably the main route of exposure to these compounds, including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), the most extensively investigated PFCs. This paper reviews the state of the science regarding the concentrations of PFCs in foodstuffs, human dietary exposure to these compounds and their health risks. The influence of processing, cooking and packaging on the PFCs levels in food is also discussed. Because of the rather limited information about human dietary exposure, studies to determine exposure to PFCs through the diet for the general population of a number of countries are clearly necessary. The correlation of PFCs body burdens and dietary intake of PFCs should be also established.

Absorption and excretion of 14C-perfluorooctanoic acid (PFOA) in Angus cattle (Bos taurus)

Perfluoroalkyl substances (PFASs), such as perfluorooctanoic acid (PFOA), are environmentally persistent industrial chemicals often found in biosolids. Application of these biosolids to pastures raises concern about the accumulation of PFOA in the edible tissues of food animals. Because data on the absorption, distribution, metabolism, and excretion (ADME) of PFOA in cattle were unavailable, a study was conducted to determine pharmacokinetic parameters following a single oral exposure (1 mg/kg body weight of (14)C-PFOA) in four Lowline Angus steers. Radiocarbon was quantified in blood, urine, and feces for 28 days and in tissues at the time of slaughter (28 days) by liquid scintillation counting (LSC) or by combustion analysis with LSC with confirmation by liquid chromatography-tandem mass spectrometry (LC-MS/MS). (14)C-PFOA was completely absorbed and excreted (100.7 ± 3.3% recovery) in the urine within 9 days of dosing. The plasma elimination half-life was 19.2 ± 3.3 h. No (14)C-PFOA-derived radioactivity was detected in edible tissues. Although PFOA was rapidly absorbed, it was also rapidly excreted by steers and did not persist in edible tissues, suggesting meat from cattle exposed to an acute dose of PFOA is unlikely to be a major source of exposure to humans.

Partitioning characteristics of perfluorooctane sulfonate between water and foods

As a persistent, bioaccumulative, and toxic organic pollutant, perfluorooctane sulfonate (PFOS) has been found ubiquitously in the environment, including in tap water. For the first time, we studied PFOS sorption from water to foods (nine commonly consumed vegetables, three meats, and cereals) at two temperatures to estimate the daily intake of PFOS attributable to cooking and food preparation. The values of the food water-distribution coefficient (KF/W, l/kg) of PFOS ranged from 7 to 19 l/kg for most vegetables and from 19 to 38 l/kg for meats. Celery exhibited the highest affinity toward PFOS (KF/W=39.8±3.4 l/kg), whereas onions showed the lowest affinity toward PFOS (KF/W=1.1±0.4 l/kg). Adding table salt (sodium chloride) greatly increased PFOS sorption in most foods, except for celery and meats. The results indicate that human exposure to PFOS could result from the sorption of PFOS from water to food during food preparation, especially when using table salt. The average daily intake of PFOS through this route was estimated. Furthermore, raw and unprocessed foods (vegetables, meats, and cereals) bought from farmers' markets and grocery stores were basically free of PFOS and other long-chain perfluoroalkyl acids.

Determination of perfluorinated chemicals in food and drinking water using high-flow solid-phase extraction and ultra-high performance liquid chromatography/tandem mass spectrometry

For this study, we developed methods of determining ten perfluorinated chemicals in drinking water, milk, fish, beef, and pig liver using high-flow automated solid-phase extraction (SPE) and ultra-high performance liquid chromatography/tandem mass spectrometry. The analytes were separated on a core-shell Kinetex C18 column. The mobile phase was composed of methanol and 10-mM N-methylmorpholine. Milk was digested with 0.5 N potassium hydroxide in Milli-Q water, and was extracted with an Atlantic HLB disk to perform automated SPE at a flow rate ranged from 70 to 86 mL/min. Drinking water was directly extracted by the SPE. Solid food samples were digested in alkaline methanol and their supernatants were diluted and also processed by SPE. The disks were washed with 40% methanol/60% water and then eluted with 0.1% ammonium hydroxide in methanol. Suppression of signal intensity of most analytes by matrixes was lower than 50%; it was generally lower in fish and drinking water but higher in liver. Most quantitative biases and relative standard deviations were lower than 15%. The limits of detection for most analytes were sub-nanograms per liter for drinking water and sub-nanograms per gram for solid food samples. This method greatly shortened the time and labor needed for digestion, SPE, and liquid chromatography. This method has been applied to analyze 14 types of food samples. Perfluorooctanoic acid was found to be the highest among the analytes (median at 3.2-64 ng/g wet weight), followed by perfluorodecanoic acid (0.7-25 ng/g) and perfluorododecanoic acid (0.6-15 ng/g).

Maternal seafood consumption and infant birth weight, length and head circumference in the Norwegian Mother and Child Cohort Study

Results from previous studies on associations between maternal fish and seafood intakes and fetal growth are inconclusive. The aim of the present study was to investigate how maternal intakes of seafood, subtypes of seafood and supplementary n-3 fatty acids were associated with infant birth weight, length and head circumference in a prospective study in Norway. The study population included 62 099 participants in the Norwegian Mother and Child Cohort Study. The mothers answered an FFQ in mid pregnancy. The FFQ comprised detailed questions about intake of various seafood items and n-3 supplements. Data on infant birth weight, length and head circumference were obtained from the Medical Birth Registry. We used multivariable regression to examine how total seafood, various seafood subtypes and supplementary n-3 intakes were associated with birth size measures. Total seafood intake was positively associated with birth weight and head circumference. Lean fish was positively associated with all birth size measures; shellfish was positively associated with birth weight, while fatty fish was not associated with any birth size measures. Intake of supplementary n-3 was negatively associated with head circumference. The relative risk of giving birth to a small baby ( < 2500 g) in full-term pregnancies was significantly lower in women who consumed >60 g/d of seafood than in women who consumed ≤ 5 g/d (OR = 0·56 (95 % CI 0·35, 0·88). In conclusion, maternal seafood consumption was positively associated with birth size, driven by lean fish intake, while supplementary n-3 intake was negatively associated with infant head circumference.

PFOS or PreFOS? Are perfluorooctane sulfonate precursors (PreFOS) important determinants of human and environmental perfluorooctane sulfonate (PFOS) exposure?

The extent to which perfluorooctanesulfonate precursors (PreFOS) play a role in human or environmental exposure to perfluorooctanesulfonate (PFOS) is not well characterized. The diversity of manufactured PreFOS and its degradation products (e.g. C(8)F(17)SO(2)R and C(8)F(17)SO(2)NR'R'', where R is H or F, and R' and R'' are various) has made it difficult to track their fate. Temporal trends of PFOS in both humans and wildlife are discrepant, thus it is difficult to predict future exposure, and hypotheses about the role of PreFOS have been raised. Although abiotic degradation of commercially important PreFOS materials requires further research, current data suggest that the yield of PFOS is negligible or minor. On the other hand, in vivo biotransformation of PreFOS yields PFOS as the major metabolite, and >32% yields have been observed. In Canadians, exposure to PreFOS was equivalent or greater than direct PFOS exposure prior to 2002. In most ocean water, PFOS is dominant to PreFOS, but in the oceans east of Greenland there may be more PreFOS than PFOS, consistent with the fact that whales and humans in this region also show evidence of substantial PreFOS exposure. Quantitative assessments of PFOS body-burdens coming from PreFOS are complicated by the fact that PreFOS partitions to the cellular fraction of blood, thus biomonitoring in serum under predicts PreFOS relative to PFOS. Many unknowns exist that prevent accurate modelling, thus analytical methods that can distinguish directly manufactured PFOS, from PFOS that has been biotransformed from PreFOS, should be applied in future human and environmental monitoring. Two new source tracking principles are presented and applied to human serum.

Analysis of polyfluorinated compounds in foods

Polyfluorinated compounds (PFCs) are a relatively new and diverse set of compounds analyzed as contaminants in food. Their unique physical-chemical properties dictate the methods used for their analysis. Current analyses of the more volatile PFCs involve gas chromatography-mass spectrometry; liquid chromatography-tandem mass spectrometry is generally used for the less volatile PFCs. Considerations in the analysis of PFCs in foods include contamination from the widespread presence of materials that contain various PFCs, endogenous interfering compounds, and matrix effects. Future opportunities for research on PFCs in food exist, particularly in the areas of biological molecule-PFC interactions and the effects of food processing on these interactions. Future research will be facilitated by the synthesis of a wider variety of analytical standards.

Levels in food and beverages and daily intake of perfluorinated compounds in Norway

Perfluorinated compounds (PFCs) have been determined in 21 samples of selected food and beverages such as meat, fish, bread, vegetables, milk, drinking water and tea from the Norwegian marked. Up to 12 different PFCs were detected in the samples. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were found in concentrations similar to or lower than what has been observed in other studies world-wide. Differences in the relative proportion of PFOA and PFOS between samples of animal origin and samples of non-animal origin were observed and support findings that PFOS has a higher bioaccumulation potential in animals than PFOA. Based on these 21 measurements and consumption data for the general Norwegian population, a rough estimate of the total dietary intake of PFCs was found to be around 100 ng d(-1). PFOA and PFOS contributed to about 50% of the total intake. When dividing the population in gender and age groups, estimated intakes were decreasing with increasing age and were higher in males than females. The estimated intakes of PFOS and PFOA in the present study are lower than what has been reported in studies from Spain, Germany, United Kingdom, Canada and Japan. This study illustrates that by improving the analytical methods for determination of PFC in food samples, a broad range of compounds can be detected, which is important when assessing dietary exposure.

Perfluorinated substances in human food and other sources of human exposure

The widespread distribution and degradation of PFCs in the environment results in a very complex exposure pattern, which makes it difficult to define the relative contribution to human exposure from different exposure pathways. The present review is designed to provide an overview of the existing data on levels of PFCs measured in the human diet and in drinking water. Data on levels of PFCs in the human diet are rather scarce, but the level in the fish appear to be well documented. Among PFCs, PFOS and PFOA are the best studied compounds in fish from both experimental and monitoring studies. Recently, the number of publications that address other PFCs has increased, but the total number available is still limited. In general, we discovered that care should be exercised when using the reviewed data, because, in the majority of publications, quality control and/or details on analysis are, at least partly, lacking. It has been well documented that PFOA and PFOS have the potential to accumulate in fish and concentrations up to 7 and 170 ng/g wwt, respectively in edible fish species have been found. PFOS is the most crucial and prominent compound identified, followed by the PFOA. Also, in aquatic invertebrate such as shrimps, mussels, clams, and oysters, high PFOS levels have been reported (up to 387 ng/g wwt). However in most publications PFC level reported in molluscs were less than 1 ng/g wwt. Positive correlations were found between PFC body burden and self reported fish consumption. In recognition of the potential for human exposure to PFCs via fish consumption, the Minnesota Department of Health has recently issued fish consumption advisories for contaminated sections of the Mississippi River. It is interesting to note that 79% of the reviewed publications on PFCs in the whole fish homogenates exceed the that threshold. Moreover, five of the PFC concentration reported in muscles tissue exceeded the advisory level of 38 ng/g wwt. Even though several authors concluded that consumption of contaminated food and drinking water constitutes the major exposure pathway for humans, only a few reports on PFCs in composite food exist. Food can be contaminated in an indirect way, because PFCs are widely used in food-packaging coatings and cooking materials. On the other hand, PFCs can also enter food organisms via environmental routes such as inhalation or adsorption from air. In a few studies, composite samples, duplicate diet samples, or other food items were analyzed for several PFCs, PFOS and PFOA, PFHpA, PFHxA, and PFHxS were meAsured and displayed concentrations ranging from-detected up to 15 ng/g wwt. In one study, a very high PFOA concentration of 118 ng/g were reported, but overall, PFC levels are below 10 ng/g wwt. It is important to note that, among all studies reviewed, PFCs were found in a maximum of 50% of the analyzed samples and generally only in 10% or less of samples analyzed. In contrast to what is observed in fish and other food items PFOA levels in drinking water (ND - 50 ng/L) and other PFCs (1-3 ng/L). In one study, extremely high values (519 ng/L) were measured in drinking water of a contaminated area in the Ruhr region. In Spain, bottled water was analyzed and four PFCs (PFOA, PFNA,PFDA and PFHpA) were found at low levels (<1 ng/L). Because of higher levels found in drinking water at several locations, some provisional drinking water guideline values for PFOS and PFOA have already been established, e.g., in the UK, Bavaria, and Minnesota. Since PFCs are present both in food and drinking water, Tolerable Daily Intake values for PFOS and PFOA have also been proposed by several institutes in Europe and in the USA. The ingestion of dust through hand-to-mouth transfer from indoor house dust can also be a potential source of PFC exposure, especially for toddlers and children. In publications on PFCs in indoor dust, the mean PFOS and PFOA levels varied between 39 and 1,200 ng/g and between 11 and 220 ng/g, respectively. Overall, it is clear that there is still lack of PFC exposure data for food and beverages, which renders the assessment of the contribution of the diet to total human PFC exposure uncertain. It is, therefore, appropriate that several scientific projects have recently been launched that addresses the assessment of human exposure to PFCs and related compounds from dietary sources.

Fish consumption as a source of human exposure to perfluorinated alkyl substances in Sweden - analysis of edible fish from Lake Vättern and the Baltic Sea

Perfluorinated alkyl substances (PFAS) were analyzed in muscle tissue from edible fish species caught in the second largest freshwater lake in Sweden, Lake Vättern (LV), and in the brackish water Baltic Sea (BS). Perfluorooctane sulfonate (PFOS) was the predominant PFAS found. PFOS concentrations were higher in LV (medians 2.9-12 ng g(-1) fresh weight) than in BS fish (medians 1.0-2.5 ng g(-1) fresh weight). Moreover, LV fish was more contaminated with several other PFAS than BS fish. This may be due to anthropogenic discharges from urban areas around LV. The PFAS pattern differed between LV and BS fish, indicating different sources of contamination for the two study areas. Human exposure to PFOS via fish intake was calculated for three study groups, based on consumption data from literature. The groups consisted of individuals that reported moderate or high consumption of BS fish or high consumption of LV fish, respectively. The results showed that PFOS intake strongly depended on individual fish consumption as well as the fish catchment area. Median PFOS intakes were estimated to 0.15 and 0.62 ng kg(-1) body weight (bw) d(-1) for the consumers of moderate and high amounts of BS fish, respectively. For the group with high consumption of LV fish a median PFOS intake of 2.7 ng kg(-1)bw d(-1) was calculated. Fish consumption varied considerably within the consumer groups, with maximum PFOS intakes of 4.5 (BS fish) or 9.6 ng kg(-1)bw d(-1) (LV fish). Comparison of our results with literature data on PFOS intake from food suggests that fish from contaminated areas may be a significant source of dietary PFOS exposure.