Perfluorooctanesulfonate and related fluorinated hydrocarbons in mink and river otters from the United States

Historical comparison of perfluorooctanesulfonate, perfluorooctanoate, and other fluorochemicals in human blood

The purpose of this investigation was to determine whether there has been a change in the human blood concentration of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and five other fluorochemicals since 1974. Blood samples were collected in 1974 (serum) and 1989 (plasma) from volunteer participants of a large community health study. The study included a total of 356 samples (178 from each time period). These samples were analyzed by high-pressure liquid chromatography/tandem mass spectrometry methods. The median 1974 and 1989 fluorochemical concentrations, respectively, were as follows: PFOS, 29.5 ng/mL vs. 34.7 ng/mL; PFOA, 2.3 ng/mL vs. 5.6 ng/mL; perfluorohexanesulfonate (PFHS), 1.6 ng/mL vs. 2.4 ng/mL; and N-ethyl perfluorooctanesulfonamidoacetate (PFOSAA), less than the lower limit of quantitation (LLOQ; 1.6 ng/mL, vs. 3.4 ng/mL). For N-methyl perfluorooctanesulfonamidoacetate (M570), perfluorooctanesulfonamide, and perfluorooctanesulfonamidoacetate, median serum concentrations in both years were less than the LLOQ values (1.0, 1.0, and 2.5 ng/mL, respectively). Statistical analysis of 58 paired samples indicated that serum concentrations of PFOS, PFOSAA, PFOA, PFHS, and M570 were significantly (p < 0.001) higher in 1989 than in 1974. The data from 1989 were then compared with geometric mean fluorochemical concentrations of serum samples collected in 2001 from 108 American Red Cross adult blood donors from the same region. Except for M570, there were no statistically significant (p < 0.05) geometric mean fluorochemical concentration differences between the 1989 and 2001 samples. In conclusion, based on this study population, PFOS and other serum fluorochemical concentrations have increased between 1974 and 1989. Comparison with other regional data collected in 2001 did not suggest a continued increase in concentrations since 1989.

Perflouroalkyl contaminants in liver tissue from East Greenland polar bears (Ursus maritimus)

Perfluoroalkyl substances were determined in polar bears (Ursus maritimus) collected in East Greenland (69 degrees 00'N to 74 degrees 00"N) to compare with other populations and to examine effects of age and gender on concentrations of these contaminants. Hepatic tissue (n = 29) was analyzed for perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorohexane sulfonate, heptadecafluorooctane sulfonamide (PFOSA), and perfluoroalkyl carboxylates (PFCAs) with C9-C15 perfluorinated carbon chains by liquid chromatography tandem mass spectrometry. Concentrations of PFOS found in samples from East Greenland (mean = 2,470+/-1,320 ng/g wet weight) were similar to Hudson Bay, Canada, and both populations had significantly greater concentrations than those reported for Alaska, suggesting a spatial trend. Male bears showed a significant increase in concentration up to age six for PFCAs with C10-C14 carbon chains (r2 > or = 0.50, p < or = 0.05). Significant correlations were found between adjacent chain length PFCAs, (e.g., PFNA to PFDA: p < 0.05; r2 = 0.90). This may indicate a common source for these chemicals, although the specifics of source and mode of transport are unknown. No significant correlations were found between concentrations of PFCAs in liver tissue and previously reported polychlorinated biphenyl (PCB) congeners analyzed in fat samples from the same bears.

Perfluorinated organic compounds in human blood serum and seminal plasma: a study of urban and rural tea worker populations in Sri Lanka

Concentrations and accumulation of 13 fluorinated organic compounds (FOCs) in human sera and seminal plasma were measured in an Asian developing country, Sri Lanka. Six of the FOCs, PFOS (perfluorooctanesulfonate), PFHS (perfluorohexanesulfonate), PFUnA (perfluoroundecanoic acid), PFDA (perfluorodecanoic acid), PFNA (perfluorononanoic acid) and PFOA (perfluorooctanoic acid), were detected in all of the sera samples. Measurable quantities of two main perfluorosulfonates, PFOS and PFHS, were found in all seminal plasma samples. The detection frequency of the predominant perfluoroalkylcarboxylate, PFOA, in seminal plasma was >70%. Accumulation of PFOS in sera was significantly positively correlated with PFOA, PFHS and PFNA. Positive linear regressions were also found between PFNA and PFUnA and PFNA and PFDA suggesting that these compounds may have a similar origin of exposure and accumulation. Significantly positive associations were observed for partitioning of both PFOS and PFNA between sera and seminal plasma. The accumulation of FOCs was not significantly different in sera from Colombo (urban population) and Talawakele (rural conventional tea workers). However, the Haldummulla population (rural organic tea workers) had relatively lower exposure to FOCs compared to the other two groups, urban and rural conventional tea workers. Concentrations of FOCs in Sri Lanka were similar to those reported for industrialized countries suggesting that human exposure to such chemicals is widespread even in developing countries. The novel finding of FOCs in human seminal plasma implies that further studies are needed to determine whether long-term exposure in humans can result in reproductive impairments.

Synthesis of environmentally relevant fluorinated surfactants--a review

In the past years there has been a growing interest in fluorinated persistent organic pollutants such as perfluorooctanesulfonic acid, perfluorooctanesulfonamides, perfluorinated carboxylic acids and fluorotelomer alcohols. Although these compounds have probably been present in the environment for many decades, we are only now beginning to realize that these environmental contaminants may have serious environmental and health effects. This article gives a state-of-the-art review of synthetic approaches that have been employed for the synthesis of these environmentally relevant fluorinated compounds. Perfluorooctanesulfonic acid derivatives, in particular, pose a problem because only a few perfluorooctanesulfonic acid derivatives are available from commercial sources--a fact that limits the ability of researchers worldwide to further study these compounds. Because of the limited literature available, this article also describes synthetic approaches for shorter chain homologues or perfluoroether analogues that can potentially be applied for the synthesis of perfluorooctanesulfonic acid derivatives. The preparation of typical starting materials for the synthesis of perfluorooctanesulfonic acid derivatives such as the perfluoroalkanesulfonyl fluorides and chlorides will be discussed. Subsequently, their conversion into relevant perfluoroalkane sulfonate salts (R(F)SO3M), sulfonamides (R(F)SO2NH2), N-alkyl sulfonamides (R(F)SO2NHR, R = alkyl), N,N-dialkyl sulfonamides (R(F)SO2NR2, R = alkyl), sulfonamidoethanol (R(F)SO2NRCH2CH2OH, R = -H, -CH3 or -C2H5) and sulfonamidoacetates (R(F)SO2NRCH2CO2H, R = -H, -CH3 or -C2H5) will be described. Many perfluorinated carboxylic acids and fluorotelomer alcohols are available from commercial sources. The review of the synthesis of these two classes of fluorinated compounds includes a review of their industrial synthesis and the synthesis of relevant degradation products.

Development and characterization of a solvent extraction–gas chromatographic/mass spectrometric method for the analysis of perfluorooctanesulfonamide compounds in solid matrices

A method utilizing solvent extraction and analysis by gas chromatography-positive chemical ionization mass spectrometry (SE-GC-PCIMS) was developed for the analysis of three neutral hydrophobic perfluorooctanesulfonamide compounds [perfluorooctanesulfonamide (PFOSA), N-ethyl perfluorooctanesulfonamide (N-EtPFOSA), and N,N-diethyl perfluorooctanesulfonamide (N,N-Et2PFOSA)]. These compounds are suspected metabolic precursors of perfluorooctane sulfonate. The SE-GC-PCI-MS method was used to analyze all three perfluorooctanesulfonamides in fast food, fish, and Arctic marine mammal liver samples. The SE-GC-PCI-MS method produced relatively higher recoveries of the analytes (averaging 83 +/- 6%, 84 +/- 9%, and 89 +/- 19% for N,N-Et2PFOSA, N-EtPFOSA, and PFOSA, respectively) with lower coefficients of variation, and less susceptibility to matrix effects, than ion pair extraction-liquid chromatography-tandem mass spectrometric methods. Method detection limits (MDLs) were 100, 120, and 250 pg/g for N,N-Et2PFOSA, N-EtPFOSA, and PFOSA, respectively. The three compounds were found at concentrations ranging from below the MDL to 22 ng/g wet weight in fast food, fish, and Arctic marine mammal liver samples.

Determination of perfluorooctanoic acid (PFOA) extractable from the surface of commercial cookware under simulated cooking conditions by LC/MS/MS

Salts of pentadecafluorooctanoic acid (PFOA) are polymerization aids used in the manufacture of fluoropolymers; one of the applications of fluoropolymers is the coating of metal cookware products. A method was developed to determine if PFOA might be present in and extracted from the surface of commercial frying pans coated with a DuPont fluoropolymer under simulated cooking conditions. Commercial grade cookware was obtained, then extracted with water and ethanol/water mixtures at 100 and 125 degrees C, and the resulting extracts were analyzed by liquid chromatography tandem mass spectrometry (LC/MS/MS). Detection and quantification limits as low as 100 pg cm(-2) were demonstrated. None of the fluoropolymer treated cookware samples analyzed showed detectable levels of PFOA when extracted under simulated cooking conditions.

A global survey of perfluorinated acids in oceans

Perfluorinated acids and their salts have emerged as an important class of global environmental contaminants. Biological monitoring surveys conducted using tissues of marine organisms reported the occurrence of perfluorooctanesulfonate (PFOS) and related perfluorinated compounds in biota from various seas and oceans, including the Arctic and the Antarctic Oceans. Occurrence of perfluorinated compounds in remote marine locations is of concern and indicates the need for studies to trace sources and pathways of these compounds to the oceans. Determination of sub-parts-per-trillion (ng/L) or parts-per-quadrillion (pg/L) concentrations of aqueous media has been impeded by relatively high background levels arising from procedural or instrumental blanks. Our research group has developed a reliable and highly sensitive analytical method by which to monitor perfluorinated compounds in oceanic waters. The method developed is capable of detecting PFOS, perfluorohexanesulfonate (PFHS), perfluorobutanesulfonate (PFBS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), and perfluorooctanesulfonamide (PFOSA) at a few pg/L in oceanic waters. The method was applied to seawater samples collected during several international research cruises undertaken during 2002-2004 in the central to eastern Pacific Ocean (19 locations), South China Sea and Sulu Seas (five), north and mid Atlantic Ocean (12), and the Labrador Sea (20). An additional 50 samples of coastal seawater from several Asian countries (Japan, China, Korea) were analyzed. PFOA was found at levels ranging from several thousands of pg/L in water samples collected from coastal areas in Japan to a few tens of pg/L in the central Pacific Ocean. PFOA was the major contaminant detected in oceanic waters, followed by PFOS. Further studies are being conducted to elucidate the distribution and fate of perfluorinated acids in oceans.

Effects of prenatal perfluorooctane sulfonate (PFOS) exposure on lung maturation in the perinatal rat

BACKGROUND

Perfluorooctane sulfonate (PFOS), found widely in wildlife and humans, is environmentally and metabolically stable. Environmental PFOS may be from its use as a surfactant, hydrolysis of perfluorooctanesulfonyl fluoride, and degradation of N-alkyl-perfluorooctanesulfonamide compounds formerly used in numerous applications. Prenatal exposure to PFOS in rodents causes neonatal mortality; treatment on gestation days (GD) 19-20 is sufficient to induce neonatal death in rats. Affected pups are born alive but present with labored breathing. Their lungs are pale and often do not expand fully on perfusion.

METHODS

Pregnant Sprague-Dawley rats received 0, 25, or 50 mg/kg/day PFOS/K+ orally on GD 19-20. Lungs from GD 21 fetuses and neonates were prepared for histology and morphometry. Rescue experiments included co-administration of dexamethasone or retinyl palmitate with PFOS. Pulmonary surfactant was investigated with mass spectrometry in GD 21 amniotic fluid and neonatal lungs. Microarray analysis was carried out on PND 0 lungs.

RESULTS

Histologically, alveolar walls were thicker in lungs of PFOS-exposed newborns compared to controls. The ratio of solid tissue:small airway was increased, suggesting immaturity. Rescue studies were ineffective. Phospholipid concentrations and molecular speciation were unaffected by PFOS. No changes in markers of alveolar differentiation were detected by microarray analysis.

CONCLUSIONS

Morphometric changes in lungs of PFOS exposed neonates were suggestive of immaturity, but the failure of rescue agents and normal pulmonary surfactant profile indicate that the labored respiration and mortality observed in PFOS-treated neonates was not due to lung immaturity.

Prenatal window of susceptibility to perfluorooctane sulfonate-induced neonatal mortality in the Sprague-Dawley rat

The critical period for increased neonatal mortality induced by perfluorooctane sulfonate (PFOS) exposure was evaluated in the rat. Timed-pregnant Sprague-Dawley rats were treated by oral gavage with 25 mg/kg/d PFOS/K(+) on four consecutive days (gestation days (GD) 2-5, 6-9, 10-13, 14-17, or 17-20) or with 0, 25, or 50 mg/kg/d PFOS/K(+) on GD 19-20. Controls received vehicle (10 ml/kg 0.5% Tween-20) on these days. Maternal weight gain was reduced in treated animals during dosing, as were food and water consumption. Following a 4-day treatment, litter size at birth was unaffected while pup weight was similarly reduced in the three earliest PFOS groups. All PFOS groups experienced decreases in survival while controls remained near 100%. Neonatal survival decreased in groups dosed later during gestation, approaching 100% with dosing on GD 17-20. Most deaths occurred before postnatal day (PND) 4, with the majority in the first 24 hours. Maternal serum PFOS levels on GD 21 were higher in groups exhibiting higher mortality. Following a 2-day treatment, PFOS groups experienced significant pup mortality by PND 1. Neonatal mortality continued through PND 5, when survival was 98, 66, and 3% for the 0, 25, and 50 mg/kg groups, respectively. Pup weight was reduced in treated groups with surviving litters. Gross dissection and histological examination of lungs revealed differences in maturation between control and treated animals on PND 0. We conclude that exposure to PFOS late in gestation is sufficient to induce 100% pup mortality and that inhibition of lung maturation may be involved.

Perfluorooctane sulfonate (PFOS) and related perfluorinated compounds in human maternal and cord blood samples: assessment of PFOS exposure in a susceptible population during pregnancy

Fluorinated organic compounds (FOCs), such as perfluorooctane sulfonate (PFOS), perfluoro-octanoate (PFOA), and perfluorooctane sulfonylamide (PFOSA), are widely used in the manufacture of plastic, electronics, textile, and construction material in the apparel, leather, and upholstery industries. FOCs have been detected in human blood samples. Studies have indicated that FOCs may be detrimental to rodent development possibly by affecting thyroid hormone levels. In the present study, we determined the concentrations of FOCs in maternal and cord blood samples. Pregnant women 17-37 years of age were enrolled as subjects. FOCs in 15 pairs of maternal and cord blood samples were analyzed by liquid chromatography-electrospray mass spectrometry coupled with online extraction. The limits of quantification of PFOS, PFOA, and PFOSA in human plasma or serum were 0.5, 0.5, and 1.0 ng/mL, respectively. The method enables the precise determination of FOCs and can be applied to the detection of FOCs in human blood samples for monitoring human exposure. PFOS concentrations in maternal samples ranged from 4.9 to 17.6 ng/mL, whereas those in fetal samples ranged from 1.6 to 5.3 ng/mL. In contrast, PFOSA was not detected in fetal or maternal samples, whereas PFOA was detected only in maternal samples (range, < 0.5 to 2.3 ng/mL, 4 of 15). Our results revealed a high correlation between PFOS concentrations in maternal and cord blood (r2 = 0.876). However, we did not find any significant correlations between PFOS concentration in maternal and cord blood samples and age bracket, birth weight, or levels of thyroid-stimulating hormone or free thyroxine. Our study revealed that human fetuses in Japan may be exposed to relatively high levels of FOCs. Further investigation is required to determine the postnatal effects of fetal exposure to FOCs. Key words: cord blood, fluorinated organic compounds, human, PFOA, PFOS, PFOSA, pregnancy.

Mixing of perfluorinated carboxylic acids with dipalmitoylphosphatidylcholine

Perfluorinated acids are emerging as an important class of persistent environmental pollutant, thus raising human health concerns. To understand the behavior of these compounds in biological systems, the mixing behavior of two perfluorinated acids, perfluorododecanoic and perfluorotetradecanoic acid, with dipalmitoylphosphatidylcholine (DPPC) was studied in monolayers at the air-water interface and in fully hydrated DPPC bilayers. The mixing behavior of both acids was indicative of an attractive interaction and partial miscibility with DPPC at the air-water interface. In the bilayer studies, the fluorinated acids cause peak broadening and elimination of the pretransition of DPPC. The onset temperature of the main phase transition remains constant in the presence of the fluorinated acids suggesting immiscibilities in the gel phase. Below X(DPPC) = 0.97 significant peak broadening of the main phase transition can be observed. These results suggest strong interaction between the respective acid and DPPC, and that both acids are able to partition into the lipid bilayer. However, their mixing behavior is far from ideal, thus suggesting the presence of domains or lipid aggregates with high acid concentrations which may (adversely) impact the function of biological mono- and bilayers.

The developmental toxicity of perfluoroalkyl acids and their derivatives

Perfluoroalkyl acids such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have applications in numerous industrial and consumer products. Although the toxicology of some of these compounds has been investigated in the past, the widespread prevalence of PFOS and PFOA in humans, as demonstrated in recent bio-monitoring studies, has drawn considerable interest from the public and regulatory agencies as well as renewed efforts to better understand the hazards that may be inherent in these compounds. This review provides a brief overview of the perfluoroalkyl chemicals and a summary of the available information on the developmental toxicity of the eight-carbon compounds, PFOS and PFOA. Although the teratological potentials of some of these chemicals had been studied in the past and the findings were generally unremarkable, results from recent postnatal studies on developmental and reproductive indices have prompted consideration of their relevance to human health risk. Based on current understanding of the developmental effects of PFOS and PFOA in rodents, several avenues of research are suggested that would further support the risk assessment of these perfluorinated organic chemicals.

Biochemical effect evaluation of perfluorooctane sulfonic acid-contaminated wood mice (Apodemus sylvaticus)

Wood mice (Apodemus sylvaticus) were captured at Blokkersdijk, a nature reserve in the immediate vicinity of a fluorochemical plant in Antwerp, Belgium, and at Galgenweel, 3 kilometers farther away. The liver perfluorooctane sulfonic acid (PFOS) concentrations in the Blokkersdijk mice were extremely high (0.47-178.55 micro g/g wet weight). Perfluorononanoic, perfluorodecanoic, perfluoroundecanoic, and perfluorododecanoic acids were found sporadically in the liver tissue of the Blokkersdijk mice. The liver PFOS concentrations at Galgenweel were significantly lower than those at Blokkersdijk (0.14-1.11 micro g/g wet weight). Further results suggest sex independence of the liver PFOS levels, increased levels of PFOS bioaccumulation in older mice, and maternal PFOS transfer to the young. Several liver end points were significantly elevated in the Blokkersdijk mice: liver weight, relative liver weight, peroxisomal beta-oxidation activity, microsomal lipid peroxidation level, and mitochondrial fraction protein content. For the mitochondrial fraction catalase activity, no significant difference between locations was found. The liver weight, relative liver weight, and liver microsomal lipid peroxidation level increased significantly with the liver PFOS concentration. No indications for PFOS-mediated effects on the serum triglyceride, cholesterol, or potassium levels were obtained. The liver PFOS concentration was negatively related to the serum alanine aminotransferase activity.

Serum concentrations of perfluorooctanesulfonate and other fluorochemicals in an elderly population from Seattle, Washington

Perfluorooctanesulfonyl fluoride (POSF, C8F17SO2F) related-materials have been used as surfactants, paper and packaging treatments, and surface (e.g., carpet, textile, upholstery) protectants. A metabolite, perfluorooctanesulfonate (PFOS, C8F17SO3-), has been identified in the serum and liver of non-occupationally exposed humans and wildlife. Because of its persistence, an important question was whether elderly humans might have higher PFOS concentrations. From a prospective study designed to examine cognitive function in the Seattle (WA) metropolitan area, blood samples were collected from 238 dementia-free subjects (ages 65-96). High-pressure liquid chromatography-electrospray tandem mass spectrometry determined seven fluorochemicals: PFOS; N-ethyl perfluorooctanesulfonamidoacetate; N-methyl perfluorooctanesulfonamidoacetate; perfluorooctanesulfonamidoacetate; perfluorooctanesulfonamide; perfluorooctanoate; and perfluorohexanesulfonate. Serum PFOS concentrations ranged from less than the lower limit of quantitation (3.4 ppb) to 175.0 ppb (geometric mean 31.0 ppb; 95% CI 28.8-33.4). An estimate of the 95% tolerance limit was 84.1 ppb (upper 95% confidence limit 104.0 ppb). Serum PFOS concentrations were slightly lower among the most elderly. There were no significant differences by sex or years residence in Seattle. The distributions of the other fluorochemicals were approximately an order of magnitude lower. Similar to other reported findings of younger adults, the geometric mean serum PFOS concentration in non-occupational adult populations likely approximates 30-40 ppb with 95% of the population's serum PFOS concentrations below 100 ppb.

Predicting the biodegradation products of perfluorinated chemicals using CATABOL

Perfluorinated chemicals (PFCs) form a special category of organofluorine compounds with particularly useful and unique properties. Their large use over the past decades increased the interest in the study of their environmental fate. Fluorocarbons may have direct or indirect environmental impact through the products of their decomposition in the environment. It is a common knowledge that biodegradation is restricted within non-perfluorinated part of molecules: however, a number of studies showed that defluorination can readily occur during biotransformation. To evaluate the fate of PFCs in the environment a set of principal transformations was developed and implemented in the simulator of microbial degradation using the catabolite software engine (CATABOL). The simulator was used to generate metabolic pathways for 171 perfluorinated substances on Canada's domestic substances list. It was found that although the extent of biodegradation of parent compounds could reach 60%, persistent metabolites could be formed in significant quantities. During the microbial degradation a trend was observed where PFCs are transformed to more bioaccumulative and more toxic products. Perfluorooctanoic acid and perfluorooctanesulfonate were predicted to be the persistent biodegradation products of 17 and 27% of the perfluorinated sulphonic acid and carboxylic acid containing compounds, respectively.

Biotransformation of N-ethyl perfluorooctanesulfonamide by rainbow trout (Onchorhynchus mykiss) liver microsomes

Rainbow trout (Onchorhynchus mykiss) liver microsomes were incubated with N-ethyl perfluorooctanesulfonamide [N-EtPFOSA, C8F17SO2NH(C2H5)], to examine the possibility of in vitro biotransformation to perfluorooctane sulfonate (PFOS, C8F17SO3-) and perfluorooctanoate (PFOA, C7F15COO-). Incubations were performed by exposing trout liver microsomes to N-EtPFOSA at 8 degrees C in the dark. Reaction mixtures were analyzed after incubation periods of 0, 2, 4, 8, 16, and 30 h for N-EtPFOSA, PFOS, PFOA, and perfluorooctanesulfonamide (PFOSA, C8F17SO2NH2), a suspected intermediate. Amounts of PFOS and PFOSA were found to increase with incubation time, but only background levels of PFOA were detected. Three possible reaction pathways are proposed for the conversion of N-EtPFOSA to PFOS: (i) direct conversion of N-EtPFOSA to PFOS by deethylamination accompanied by conversion of the sulfone group to sulfonate, (ii) deethylation of N-EtPFOSA to PFOSA, followed by deamination to form PFOS, and (iii) direct hydrolysis of N-EtPFOSA. These findings represent the first report indicating a possible biotransformation of a perfluorosulfonamide to PFOS in fish and may help to explain the detection of PFOS, which is relatively involatile, and thus not likely to undergo atmospheric transport, in biota from remote regions.

Chemical ionization pathways of polyfluorinated chemicals--a connection to environmental atmospheric processes

A systematic mass spectrometry study of an industrially prolific class of polyfluorinated compounds known as telomers was conducted. The study specifically focused upon polyfluorinated alcohols along with corresponding saturated and alpha,beta-unsaturated fluoroacids. Within each class differing fluoroalkyl chain length homologues were investigated, using negative and positive chemical ionization mass spectrometry (NCI and PCI). In the case of the fluoroalcohols, NCI resulted in the production of more elaborate spectra than the other classes. Moreover, it showed the interesting production of HF(2)(-) and the complex of this species, along with F(-), with the parent molecule. These complexes resulted in the formation of the novel H(2)F(3)(-) ion. Results show that there is significant intra-molecular hydrogen bonding that occurs for these compounds, which influences the molecules fragmentation. This bonding will also influence the fate and disposition through environmental processes (e.g., V(P), k(OH), K(OW), K(OA)) which are affected by molecular geometry. Furthermore, there is an increased accumulation and persistence potential for the molecule as a function of the fluorocarbon chain length. We have shown that in conjunction with the use of mass spectroscopy the engertics of environmental processes for polyfluorinated materials can be established.

Human donor liver and serum concentrations of perfluorooctanesulfonate and other perfluorochemicals

Perfluorooctanesulfonate (PFOS, CaF17SO3-) has been identified in the serum of nonoccupationally exposed humans and in serum and liver tissue in wildlife. The purpose of this investigation was to determine whether PFOS liver concentrations in humans are comparable to the approximate 30 ng/mL average serum concentrations reported in nonoccupationally exposed subjects. Thirty-one donors (16 male and 15 female, age range 5-74) provided serum and/or liver samples for analysis of PFOS and three other fluorochemicals: perfluorosulfonamide (PFOSA, C8F17SO2NH2), perfluorooctanoate (PFOA, C7F15CO2-), and perfluorohexanesulfonate (PFHxS, C6F13SO3-). Both sera and liver samples were extracted by ion-pair extraction and quantitatively assayed using high-performance liquid chromatography electrospray tandem mass spectrometry. Liver PFOS concentrations ranged from <4.5 ng/g (limit of quantitation, LOQ)to 57.0 ng/g. Serum PFOS concentrations ranged from <6.1 ng/mL (LOQ) to 58.3 ng/mL. Among the 23 paired samples, the mean liver to serum ratio was 1.3:1 (95% confidence interval 0.9:1-1.7:1). This liver to serum ratio is comparable to that reported in a toxicological study of cynomolgus monkeys, which had liver and serum concentrations 2-3 orders of magnitude higher than observed in these human donors. This information may be useful in human risk characterization for PFOS. Liver to serum ratios were not estimated for PFOA, PFHxS, and PFOSA as 90% of the human donor liver samples were determined to be less than the LOQ.

Environmental and toxicity effects of perfluoroalkylated substances

The production, use, environmental fate, occurrence, and toxicity of perfluoroalkylated substances have been reviewed. Although only a limited number of essential physicochemical data are available, thus hampering a complete assessment of the environmental fate of PFAS, it has become clear that PFAS behave differently from other nonpolar organic micropollutants. PFAS are present in environmental media in urbanized areas both with and without fluorochemicals production sites. The presence of PFOS at levels above the limit of detection has been demonstrated in almost all organisms sampled in a global survey as well as in both nonexposed and exposed human populations. The acute and chronic ecotoxicity of PFOS, PFOA, and 8:2 FTOH to aquatic organisms is moderate to low. Acute toxicity to rodents is also low. PFOS concentrations in effluents have been reported that approach indicative target values derived from available aquatic toxicity data. PFOA has been found to be weakly carcinogenic. This review shows the importance of the perfluoroalkylated substances for the environment and the necessity to fill the current gaps in knowledge of their environmental fate and effects.

Concentrations of perfluorinated acids in livers of birds from Japan and Korea

Livers of birds collected from Japan and Korea (n = 83) were analyzed to determine the concentrations of perfluorooctanesulfonate (PFOS), perfluorooctanesulfonamide (FOSA), perfluorooctanoic acid (PFOA) and perfluorohexanesulfonate (PFHS). PFOS was found in the livers of 95% of the birds analyzed at concentrations greater than the limit of quantitation (LOQ) of 10 ng/g, wet weight. The greatest concentration of PFOS of 650 ng/g, wet weight, was found in the liver of a common cormorant from the Sagami River in Kanagawa Prefecture. Concentrations of PFOS in bird livers from Japan and Korea were within the ranges of values reported for those from the United States and certain European countries. PFOA and PFHS were found in 5-10% of the samples analyzed. The greatest concentrations of PFOA and PFHS in bird livers were 21 and 34 ng/g, wet weight, respectively. FOSA was found in all the samples (n = 10) of cormorants collected from the Sagami River in Japan. The greatest concentration of FOSA in cormorant liver was 215 ng/g, wet weight. There was no significant correlation between the concentrations of PFOS and FOSA in cormorants collected from the Sagami River. These results suggested that the distribution of FOSA is localized. No age- or gender-specific differences in fluorochemical concentrations could be discerned in birds.