Biochemical Responses and Accumulation Properties of Long-Chain Perfluorinated Compounds (PFOS/PFDA/PFOA) in Juvenile Chickens (<Emphasis Type="Italic">Gallus gallus</Emphasis>)

One-day-old male chickens were exposed via oral gavage to mixtures of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorodecanoate (PFDA) at either a low dose (0.1 mg/kg body weight [b.w.]) or a high dose (1.0 mg/kg b.w.), or a saline/ethanol vehicle control, three times a week for 3 weeks. After 3 weeks of exposure, half of the chicks were sacrificed and the other half were allowed to depurate for a further 3 weeks. No dose-dependent statistically significant differences in body/organ weights were observed among treatment and control groups after 3 weeks of exposure or after three 3 of depuration. Neither 15 histological nor 14 measured plasma biochemical parameters were significantly different in chicks from the exposed groups and vehicle controls. PFOS, PFDA, and PFOA concentrations in blood/liver/kidney samples were measured throughout the exposure and depuration periods at different time intervals. PFOS and PFDA accumulated at much higher concentrations than PFOA during the experimental periods. Interestingly, PFOS and PFDA accumulation patterns in the blood were similar during the exposure and depuration periods. The half-lives for each PFC at the 0.1 and 1.0 mg/kg doses were, respectively, approximately 15 and 17 days for PFOS, 11 and 16 days for PFDA, and 3.9 and 3.9 days for PFOA. PFDA accumulation in organs was greater than or similar to that of PFOS: the liver was the main target during exposure and the blood was the main reservoir during depuration. These results indicate that exposure to a 1.0-mg mixture of PFOS/PFDA/PFOA/kg b.w. has no adverse effect on juvenile chickens.     

Perfluoroalkyl Acids in Marine Organisms from Lake Shihwa,Korea

To our knowledge, this is the first report of concentrations of perfluorooctanesulfonate (PFOS) and other perfluoroalkyl acids (PFAs) in marine organisms from the industrialized region of Korea. Concentrations of eight PFAs were determined in three species of fish (mullet, shad, and rockfish) and three species of marine invertebrates (blue crab, oyster, and mussel) from Lake Shihwa, Korea. This is an area in which relatively great concentrations of PFAs in water and in adjacent industrial effluents have been reported. PFOS was the dominant PFA in marine organisms and most PFOS concentrations were greater than the sum of all other PFAs. The mean concentrations of PFOS were 8.1 × 10 and 3.6 × 10 ng/g, wet weight in liver and blood of fish, respectively. Perfluorocarboxylic acids (PFCAs) were also found in fish, but their concentrations were 10-fold less than those for PFOS. Of the PFCAs measured in fish, concentrations of the longer-chain perfluoroundecanoic acid (PFUnA) were the greatest. Concentrations of PFOS in soft tissues of blue crabs decreased as a function of distance from the shore where inputs from the industrialized areas are discharged into Lake Shihwa. PFOS was the only PFA detectable in mussels and oysters with a mean of 0.5 ± 0.2 and 1.1 ± 0.3 ng/g, wet weight, respectively. Concentrations of PFUnA were positively correlated with perfluorodecanoic acid (PFDA) in both the liver and blood of fish, which suggests a common source of these two PFCAs in this area. Hazard quotients developed for fish species were all less than 1.0 for fish collected in Lake Shihwa.     

HPLC Determination of Plasma Thiocyanate Concentrations in Fish Blood: Application to Laboratory Pharmacokinetic and Field-Monitoring Studies

The pharmacokinetics of thiocyanate (SCN⁻) in the blood plasma of 35-g rainbow trout (Oncorhynchus mykiss) were followed during a 20-day exposure to 39.8 mg SCN⁻ liter⁻¹ and the subsequent 16-day depuration period. SCN⁻ concentrations were determined by reverse-phase HPLC. Kinetic constants were estimated using a one-compartment first-order kinetic model fitted to the data by the computer programs BIOFAC and SYSTAT. The respective BIOFAC and SYSTAT estimates for the uptake rate constant (k₁, 0.55 and 0.49 day⁻¹), the depuration rate constant (k₂, 0.34 and 0.29 day⁻¹), and the bioconcentration factor (BCF, 1.61 and 1.66) were similar for both methods of calculation. Field studies were conducted to determine the impact of SCN⁻ on white sucker (Catostomus commersoni) populations in waters receiving SCN⁻ bearing effluents. The assessment was based on SCN⁻ concentrations in water and fish plasma, and the thyroid histology of the fish. Although SCN⁻ was detected in the water at one site, no SCN⁻ was detected in fish plasma and none of the thyroid pathology characteristic of chronic SCN⁻ exposure was present. The results suggest that SCN⁻ was not a hazard to the white sucker populations studied.     

Short-term exposures of fish to perfluorooctane sulfonate: acute effects on fatty acyl-coa oxidase activity, oxidative stress, and circulating sex steroids

This study investigated the effects of exposure to waterborne perfluorooctane sulfonate (PFOS) on oxidative stress and reproductive endpoints in fish. Exposures utilized species commonly used in toxicological testing, including the fathead minnow (Pimephales promelas) and rainbow trout (Oncorhynchus mykiss), as well as relatively insensitive taxa such as creek chub (Semotilus atromaculatus), spottail shiner (Notropis hudsonius), and white sucker (Catostomus commersoni). In all fish species, short-term (14-28 d) exposure to PFOS produced only modest mortality at concentrations consistent with environmental spill scenarios. However, PFOS consistently increased hepatic fatty acyl-CoA oxidase activity and increased oxidative damage, as quantified using the 2-thiobarbituric acid-reactive substances assay. Plasma testosterone, 11-ketotestosterone, and 17beta-estradiol titers were often elevated with PFOS exposure. Vitellogenin, the egg yolk precursor protein, was occasionally altered in the plasma with PFOS exposure, but responses varied with maturity. Oviposition frequency and egg deposition in fathead minnow were not significantly impaired with PFOS exposure, despite a trend toward progressive impairment with increasing exposure concentrations. Although short-term PFOS exposure produced significant impacts on biochemical and reproductive endpoints in fish at concentrations consistent with environmental spills, the impact of long-term exposure to environmentally relevant concentrations of PFOS is unclear.     

Pharmacokinetics and Acute Lethality of Perfluorooctanesulfonate (PFOS) to Juvenile Mallard and Northern Bobwhite

Ten-day-old mallards (Anas platyrhynchos) and northern bobwhite quail (Colinus virginianus) were fed perfluorooctanesulfonate (PFOS) in their diet for 5 days. The birds were then observed for 3 days while being given uncontaminated feed, and half of the birds were sacrificed on Day 8 of the trial. The remaining birds were maintained for an additional two weeks prior to being euthanized on Day 22 of the trial. Birds were assessed for growth, rate of feed consumption, behavior, physical injury, mortality, and gross abnormalities. Liver weight and concentrations of PFOS in blood serum and liver were also assessed. Based on the average daily intake (ADI) of PFOS calculated over the 5-day exposure period, the LD₅₀ for juvenile mallards was determined to be 150 mg PFOS/kg body weight (bw)/day, equivalent to a total cumulative dose of 750 mg PFOS/kg bw calculated over a 5-day period. For juvenile quail, the LD₅₀ based on the ADI was 61 mg PFOS/kg bw/day, equivalent to a total cumulative dose of 305 mg PFOS/kg bw. Reductions in weight gain and body weight were observed in quail from the 141 mg PFOS/kg treatment, but these measures returned to control levels by Day 22. The no-mortality dietary treatments were 70.3 and 141 mg PFOS/kg feed for quail and mallards, respectively. Both mallards and quail accumulated PFOS in blood serum and liver in a dose-dependent manner. The half-lives of PFOS in mallard blood serum and liver were estimated to be 6.86 and 17.5 days, respectively. In quail, the half-life of PFOS in liver was estimated to be 12.8 days, while the half-life of PFOS in quail blood serum could not be estimated. Concentrations of PFOS in juvenile mallard and quail liver associated with mortality are at least 50-fold greater than the single maximum PFOS concentration that has been measured in livers of avian wildlife.     

Occurrence of Perfluoroalkyl Surfactants in Water, Fish, and Birds from New York State

Concentrations of perfluorooctanesulfonate (PFOS) and several other perfluoroalkyl surfactants (PASs) were determined in nine major water bodies (n = 51) of New York State (NYS). These PASs were also measured in the livers of two species of sport fish (n = 66) from 20 inland lakes in NYS. Finally, perfluorinated compounds were measured in the livers of 10 species of waterfowl (n = 87) from the Niagara River region in NYS. PFOS, perfluorooctanoic acid (PFOA), and perfluorohexanesulfonate (PFHS) were ubiquitous in NYS waters. PFOA was typically found at higher concentrations than were PFOS and PFHS. Elevated concentrations of PFOS were found in surface waters of Lake Onondaga, and elevated concentrations of PFOA were found in the Hudson River. PFOS was the most abundant perfluorinated compound in all fish and bird samples. PFOS concentrations in the livers of fishes ranged from 9 to 315 ng/g wet weight. PFOS, PFOA, and PFOSA (perfluorooctanesulfonamide) concentrations in smallmouth and largemouth bass (taken together) caught in remote mountain lakes with no known point sources of PAS contamination were 14 to 207, < 1.5 to 6.1, and < 1.5 to 9.8 ng/g wet weight, respectively. PFOS concentrations in the livers of birds ranged from 11 to 882 ng/g wet weight. PFOS concentrations were 2.5-fold greater (p = 0.001) in piscivorous birds than in non-piscivorous birds. However, PFOA, PFOSA, and PFHS were not found in bird livers. Overall, average concentrations of PFOS in fish were 8850-fold greater than those in surface water. An average biomagnification factor of 8.9 was estimated for PFOS in common merganser relative to that in fish. This study highlights the significance of dietary fish in PFOS accumulation in the food chain. Furthermore, our results provide information on the distribution of PASs in natural waters, fish, and several bird species in NYS.     

Unique Physicochemical Properties of Perfluorinated Compounds and Their Bioconcentration in Common Carp <Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.

Carp (Cyprinus carpio L.) was exposed to perfluorinated compounds (PFCs)—perfluoroalkyl carboxylic acids (number of carbon atoms, C = 8, 11, 12, 14, 16, and 18) and perfluorooctane sulfonate (PFOS)—in bioconcentration tests to compare the bioconcentration factors (BCFs) and physicochemical properties of each specific compound. Despite having the same number of carbon atoms (C = 8), the BCFs of perfulorooctanoic acid (PFOA) and PFOS differed by more than two orders of magnitude (PFOA BCF = < 5.1 to 9.4; PFOS BCF = 720 to 1300). The highest BCFs were obtained from perfluorododecanoic acid (BCF = 10,000 to 16,000) and perfluorotetradecanoic acid (BCF = 16,000 to 17,000). The longest observed depuration half-lives were for perfluorohexadecanoic acid (48 to 54 days) and PFOS (45 to 52 days). The concentrations of PFCs were highest in the viscera, followed by the head, integument, and remaining parts of the test fish. PFCs concentrations in the integument, which was in direct contact with the test substances, were relatively greater than that of other lipophilic substance (hexachlorobenzene). It is likely that Clog P would be a better parameter than log K _ow for the prediction of BCFs for PFCs. Threshold values for PFCs bioaccumulation potential (molecular weight = 700, maximum diameter = 2 nm) seemed to deviate from those generally reported because of the specific steric bulk effect of molecule size.     

Effects of Depleted Uranium on Oxidative Stress, Detoxification, and Defence Parameters of Zebrafish Danio rerio

In this study, we investigated the effects of depleted uranium (DU), the by-product of nuclear enrichment of uranium, on several parameters related to oxidative stress, detoxification, and the defence system in the zebrafish Danio rerio. Several parameters were recorded: phenoloxidase-like (PO) activity, reactive oxygen species (ROS) production, and 7-ethoxyresrufin-O-deethylase (EROD) activity. Experiments were performed on adult and larvae D. rerio. Adult fish were exposed for 28 days at 20 μg U/L followed by a 27-day depuration period. Eggs of D. rerio were exposed for 4 days at 0, 20, 100, 250, 500, and 1,000 μg U/L. Results showed that DU increased ROS production both in adult and in larvae even at the low concentrations tested and even during the depuration period for adult D. rerio. DU also modified PO-like activity, both in the D. rerio adult and larvae experiments, but in a more transient manner. EROD activity was not modified by DU, but sex effects were shown. Results are discussed by way of comparison with other known effects of uranium in fish. Overall, these results show that the mechanisms of action of DU in fish tend to be similar to the ones existing for mammals. These results encourage the development and use of innate immune biomarkers to understand the effects of uranium and, more generally, radionuclides on the fish immune system.     

Levels, temporal trends, and tissue distribution of perfluorinated surfactants in freshwater fish from Asian countries

Perfluorinated surfactants (PFSs) in Asian freshwater fish species were analyzed to investigate tissue distribution, temporal trends, extent of pollution, and level of PFS exposure through food intake. Freshwater fish species, namely carp, snakehead, and catfish, were collected in Japan, Vietnam, India, Malaysia, and Thailand, and 10?PFSs, including perfluorooctanesulfonate (PFOS) and perfluorooctanoate, were analyzed by liquid chromatography?Ctandem mass spectrometry. PFSs in carp in Tokyo were more concentrated in kidneys (??10 PFSs?=?257?±?95?ng/g wet weight [ww]) and livers (119?±?36?ng/g?ww) than in ovaries (43?±?2?ng/g?ww) and muscles (24?±?17?ng/g?ww). Concentrations of PFOS and its precursor, perfluorooctane sulfonamide, in livers of carp and in waters in Tokyo showed a dramatic decrease during the last decade, probably because of 3?M??s phasing-out of the manufacture of perfluorooctanesulfonyl-fluoride-based products in 2000. In contrast, continuing contamination by long-chain perfluorocarboxylates (PFCAs) with????9 fluorinated carbons was seen in multiple media, suggesting that these compounds continue to be emitted. PFS concentrations in freshwater fish species in tropical Asian countries were generally lower than those in developed countries, such as Japan, e.g., for PFOS in muscle, Vietnam?<?0.05?C0.3?ng/g?ww; India?<?0.05?C0.2?ng/g?ww; Malaysia?<?0.05?C0.2?ng/g?ww; Thailand?<?0.05?ng/g?ww; and Japan (Tokyo)?=?5.1?C22?ng/g?ww. Daily intake of short-chain PFCAs with????8 fluorinated carbons from freshwater fish species in Japan was approximately one order of magnitude lower than that from drinking water, whereas daily intake of PFOS and long-chain PFCAs with????9 fluorinated carbons from freshwater fish species was comparable with or greater than that from drinking water. Because the risk posed by exposure to these compounds through intake of fish species is a matter of concern, we recommend the continued monitoring of PFS levels in Asian developing countries.     

Accumulation and depuration of metals by duckweed (Lemna perpusilla)

Duckweed (Lemna perpusilla), inhabiting a heavy coal ash, secondary retaining basin from a coal-fired power plant, was the most abundant macrophyte sampled (occupying ～95% of the surface area) during the summer-fall period of 1979. Lemna in the basin accumulated the most abundant heavy and soft metals (Cd, Cu, Fe, Mn, Zn, Cr, Pb, Ni) affiliated with heavy ash to a greater extent than found in water or coal ash sediment. After a 14-day holding period under laboratory conditions of low metal influence, some duckweed metal concentrations declined to levels similar to those found in the ash basin sediments (Pb, Cr, Ni, and Cu), while other tissue concentrations (Cd, Zn, Mn, and Fe) remained higher. During the 10-day laboratory exposure bioassay (concentrations of 0.5, 1, 10, 25, and 100 times those measured in the basin for all metals) after the depuration period, high duckweed mortality was evident within 2 to 10 days at concentrations of 10× and higher, which were coupled with excessive pH reduction (3.6-2.6). Significant accumulation relative to conditions in the ash basin occurred at ≥10× concentration (≥0.50 and 0.10 mg/liter, respectively) for Pb and Cr and at the 1× level (0.10 mg/liter) for Ni. Depuration concentrations returned to control levels within 8 days. Cu and Cd showed similar high increases (～1200 and 100 mg/liter, respectively) in bioconcentration during the 0.5 to 1.0 × concentrations but failed to be significantly depurated during the 8-day recovery period. Exposures to 0.10 mg/liter Zn and 0.05 mg/liter Mn failed to show depuration to levels similar to the control concentrations. The capacity of duckweed to accumulate potentially toxic heavy metals in coal-ash-retaining systems may have an important role upon the displacement of these elements on a seasonal basis. Aquatic elemental releases of duckweed may be minimal during the growing season due to the bioconcentration capability but can be maximal in the fall during the process of natural mortality and the resulting depuration process into the receiving drainage system.     

60Co Transfer from Water to the Rainbow Trout (Oncorhynchus mikiss Walbaum)

⁶⁰Co uptake from natural water, release and tissue distribution were investigated in the rainbow trout (Oncorhynchus mikiss), which is representative of the third order consumers of the freshwater trophic chains. The experiments were carried out on two groups of fingerling trout placed in 0.45 μm filtered river water, maintained at 12 ± 0.5°C, contaminated with about 30 Bq ml⁻¹ of ⁶⁰Co and renewed three times a week. After a 8-week exposure phase, the fish of one group were dissected to determine the contamination of the tissues and organs and the distribution of the accumulated ⁶⁰Co. The fish of the other group were placed in non-contaminated water, renewed daily, to monitor radionuclide release. After a 42-day depuration phase, the specimens were dissected to study the tissue distribution of the residual ⁶⁰Co. ⁶⁰Co accumulation from water by trout can be described by a one-compartment exponential model. The concentration factor, calculated from the ratio of the radionuclide concentration in filtered water and in the fish, reached a maximum value of 4.6 (w.w.) after 30 days exposure. After the 42-day depuration phase, the fish retained about 29% of the accumulated radionuclide. A single-compartment exponential model was fitted to the ⁶⁰Co elimination data, and the corresponding radionuclide half-life was 21 days. At the end of the exposure phase, tissue contamination study showed ⁶⁰Co accumulation by the gills, viscera (air bladder, heart and spleen) and kidneys, to be the highest. At the end of the depuration phase, the kidney was the most contaminated organ, followed by the viscera, head, gills, and liver. In both cases, ⁶⁰Co concentration was by far the lowest in the muscle, which accounted for about 45% of the total body weight and only 20% of the total radionuclide body load. Received: 27 November 1996/Revised: 14 March 1997     

Depuration kinetics and tissue disposition of PFOA and PFOS in white leghorn chickens (Gallus gallus) administered by subcutaneous implantation

Elimination kinetics and tissue disposition of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in male chickens (Gallus gallus) was determined following exposure by subcutaneous implantation. Chickens were exposed to two levels of PFOA or PFOS for 4wk and then allowed to depurate for an additional 4wk. These exposures did not cause any statistically significant changes in body index, clinical biochemistry or histology among treatments relative to the controls (p>0.05), except that concentrations of total cholesterol and phospholipids were less in chickens exposed to PFOS. The elimination rate constant for PFOA (0.150+/-0.010d(-1)) was approximately six-fold greater than that of PFOS (0.023+/-0.004d(-1)). The greatest concentrations of PFOA and PFOS were found in kidney and liver, respectively. The organ to blood ratio of PFOS concentration was increased after the whole experiment, indicating the importance of organ partitioning of PFOS in elimination kinetics. The depuration half-life of PFOA (t(1/2)=4.6d) and PFOS (t(1/2)=125d) in chickens was calculated.     

Metal toxicity to embryos and larvae of seven freshwater fish species—i. cadmium

The embryos and larvae of seven freshwater fish were exposed to low concentrations of cadmium in soft water. All species were killed or their growth retarded by concentrations ranging from about A to 12 g Cd/liter. The larvae were consistently more sensitive than the embryos. The agreement between these results and those from lifecycle chronic toxicity studies indicates that embryo and larval exposures will give reliable estimates of the chronic toxicity of cadmium to additional fish species. A 60-day exposure period appears to be appropriate for determining larval sensitivity to cadmium.The terms larval (larva) or juvenile refer to the major portion of the life stage represented during corresponding exposure periods, but may include a segment of another stage.     

Bioconcentration and Depuration of Chlorpyrifos in the Marine Mollusc Mytilus edulis

The bioconcentration and depuration of chlorpyrifos [O,O-diethyl-O-(3,5,6-trichloro-2-pyridil) phosphorothioate] for the marine mollusc Mytilus edulis was investigated under laboratory conditions in experimental aquaria. Renewal tests at concentrations of 1 and 3.2 mg/L followed by depuration tests were conducted. Organisms were exposed to pesticide concentrations for 38 days and then were maintained in clean sea water until the chlorpyrifos were eliminated. Two different methods to estimate toxicokinetic rate constants of chlorpyrifos were compared. Toxicokinetic rate constants appeared to be dependent upon the level of exposure, probably due to the toxic stress produced by the high exposure level assayed. Lipid based Bioconcentration Factor (BCF) calculated by first order kinetic fit was found to be 482 ± 86. The depuration of chlorpyrifos by mussels maintained in clean sea water was fitted to first order one-compartment model, and the depuration rate constant estimated was similar to that calculated in the bioconcentration phase. The BCF obtained was lower than expected for K _ow of chlorpyrifos, suggesting metabolic biotransformation of the parent pesticide. Received: 18 July 1996/Accepted: 5 January 1997     

Tissue-Specific Uptake and Bioconcentration of the Oral Contraceptive Norethindrone in Two Freshwater Fishes

The environmental presence of the oral contraceptive norethindrone (NET) has been reported and shown to have reproductive effects in fish at environmentally realistic exposure levels. The current study examined bioconcentration potential of NET in fathead minnow (Pimephales promelas) and channel catfish (Ictalurus punctatus). Fathead minnows were exposed to 50 μg/l NET for 28 days and allowed to depurate in clean water for 14 days. In a minimized 14-day test design, catfish were exposed to 100 μg/l NET for 7 days followed by 7-day depuration. In the fathead test, tissues (muscle, liver, and kidneys) were sampled during the uptake (days 1, 3, 7, 14, and 28) and depuration (days 35 and 42) phases. In the catfish test, muscle, liver, gill, brain, and plasma were collected during the uptake (days 1, 3, and 7) and depuration (day 14) stages. NET tissue levels were determined by gas chromatography–mass spectrometry (GC–MS). Accumulation of NET in tissues was greatest in liver followed by plasma, gill, brain, and muscle. Tissue-specific bioconcentration factors (BCFs) ranged from 2.6 to 40.8. Although NET has been reported to elicit reproductive effects in fish, the present study indicated a low potential to bioconcentrate in aquatic biota.     

Modeling polycyclic aromatic hydrocarbon bioaccumulation and metabolism in time-variable early life-stage exposures

Recent laboratory investigations into the bioaccumulation and toxicity of polycyclic aromatic hydrocarbons (PAH) have focused on low-level, time-variable exposures to early life-stage fish. Polycyclic aromatic hydrocarbon body-burden residues reported in these studies were lower than critical body-burden residues predicted by the target lipid model (TLM). To understand this discrepancy, a time-variable uptake and depuration model of PAH bioaccumulation was developed. Kinetic constants were fit using measured exposure and tissue concentrations. The resulting lipid-water partition coefficients (K(LW)) were uncorrelated with the octanol-water partition coefficient (K(OW))--a qualitatively unrealistic finding considering that numerous studies have reported a positive correlation between the two. Because PAHs are known to be metabolized, the comparison of K(LW) with K(OW) suggests that metabolism may be occurring in early life-stage fish. Therefore, the uptake and depuration model was modified to include metabolism while assuming linearity of K(LW) with K(OW). Calculated metabolism rates were positively correlated with K(OW)--a finding qualitatively similar to those of other studies. The present study provides a reasonable explanation for the discrepancy between the TLM predictions and the measured toxic effect levels. Given the time-variable exposure concentrations, the maximum measured body burdens used to relate to toxic effects may be underestimated. In addition, the maximum body burden of parent PAH plus metabolites may be a better measure in relating tissue concentrations to toxic effects. Incorporating these refinements in relating body burdens to toxic effects may result in a better comparison between TLM predictions and measured effect levels.     

Toxicity of Triphenyltin Hydroxide to Fish

Triphenyltin (TPhT) is used worldwide in pesticide formulas for agriculture. Toxic effects of this compound to aquatic life have been reported; however, the biochemical response of fish exposed to different concentrations of TPhT hydroxide (TPhTH) was investigated for the first time in this study. The lethal concentration (LC₅₀) of TPhTH to silver catfish, Rhamdia quelen, was calculated from an acute-exposure experiment (96 h). In addition, acethylcholinesterase (AChE) activity in brain and muscle—as well as glucose, glycogen, lactate, total protein, ammonia, and free amino acids in liver and muscle—were evaluated in a chronic-exposure experiment (15-day exposure). Speciation analysis of tin (Sn) was performed in fish tissues at the end of both experiments using gas chromatography coupled to a pulsed-flame photometric detector (GC-PFPD). Concentrations of TPhT, diphenyltin, and monophenyltin (reported as Sn) were lower than limits of quantification (10σ criteria). Waterborne TPhTH concentration used through the experiment was also evaluated by GC-PFPD, and no degradation of this species was observed. The LC₅₀ value for silver catfish juveniles was 9.73 μg L^?1 (as Sn). Decreased brain and muscle AChE activities were observed in fish exposed to TPhTH in relation to unexposed fish (control). Liver glycogen and lactate levels were significantly higher in fish kept at the highest waterborne TPhTH concentration compared with the control. Liver and muscle glucose levels of fish exposed to all TPhTH concentrations were significantly lower than those of control fish. Silver catfish exposed to all TPhTH concentrations showed lower total protein values and higher total free amino acids levels in liver and muscle compared with controls. Total ammonia levels in liver and muscle were significantly higher for the highest TPhTH concentration compared with controls. In conclusion, TPhTH caused metabolic alterations in silver catfish juveniles, and the analyzed parameters can also be used as bioindicators for TPhTH contamination.     

Histological changes and copper accumulation in liver and gills of the Senegales sole, Solea senegalensis.

Senegales sole, Solea senegalensis, adult specimens were subjected to sublethal copper exposure (100 microg SO(4)Cu/L) for 7 days (contamination period) and afterward kept for 4 days without copper exposure (depuration period). In contaminated and detoxified specimens, the hepatocytes indicated a great number of lipid droplets compared to the control specimens. Some ultrastructural alterations such as partial disruption of the microvilli and endothelial lining of the sinusoids were observed in the hepatocytes. Lifting and swelling of the lamellar epithelium were common lesions in S. senegalensis gills due to the copper exposure. On the other hand, in contaminated and detoxified specimens, gills demonstrated separation of respiratory epithelium; chloride and pavement cells were also altered. Copper levels in gills, and especially in liver, increased during sublethal copper exposure (up to 7 days). During the detoxification period, Cu concentrations in gills and liver experienced variable changes. The results of the study indicate that histology is a successful tool capable of revealing sensitively and selectively even the sublethal effects of heavy metals on the environment and aquatic biota.     

Effects of perfluorooctanesulfonate exposure on plasma lipid levels in the Inuit population of Nunavik (Northern Quebec)

Background

Perfluorooctanesulfonate (PFOS) was used as a surfactant in various commercial products. In rodents, exposure to this compound induced various health effects, including hypolipidemia. In human populations, the potential toxicity of PFOS is not yet fully characterized, but indications of effects on lipids are reported. A recent study reported an increase in plasma cholesterol associated with exposure to perfluorinated compounds in humans exposed through drinking water, but similar effects were not reported in all exposed human populations. PFOS is widely distributed in the environment, including the arctic biota. The Inuit of Nunavik are exposed to environmental contaminants through the consumption of fish and game. This diet is also a source of ω3-polyunsaturated fatty acids (n-3 PUFAs) that are known to lower plasma triacylglycerols.

Objective

This cross-sectional epidemiologic study aims at assessing the relationship between PFOS exposure and plasma lipids, while taking account of the concomitant hypolipidemic effect exerted by n-3 PUFAs.

Methods

Plasma concentrations of PFOS and lipids were assessed in Nunavik Inuit adults (n=723) in the framework of a large-scale environmental health study. Associations of exposure levels to age, gender and selected wild food consumption associated with n-3 PUFAs intake, as well as the exposure on lipid levels were investigated by multivariate linear modeling.

Results

In the Inuit population, PFOS exposure and n-3 PUFAs intake are related to traditional food consumption. Triacylglycerol and ratio of total cholesterol to high density lipoprotein cholesterol (HDL-C) levels were negatively associated with PFOS plasma levels, while HDL-C levels were positively associated, after adjustment for circulating levels of n-3 PUFAs and for the interaction between gender and PFOS plasma levels. Other plasma lipids, such as low density lipoprotein-cholesterol and non-HDL-C were not related to PFOS plasma concentrations.

Conclusion

The results of this study show a relationship between PFOS and plasma lipid levels in an environmentally exposed human population, and this effect appears distinct from that of n-3 PUFAs.     

Oxidative Damage and Cytotoxicity of Perfluorooctane Sulfonate on Chlorella vulgaris

We studied the effects of perfluorooctane sulfonate (PFOS) on the chlorophyll content, cell permeability, and antioxidant defense systems of the green alga Chlorella vulgaris. The results showed that the production of reactive oxygen species increased in a concentration-dependent manner after exposure to PFOS for 96 h. Superoxide dismutase and catalase activity was elevated after exposure to the lower concentrations and then decreased with higher concentrations. Malondialdehyde content was significantly higher than that of controls at the higher PFOS concentrations. Cell membrane permeability increased. These results indicate that PFOS exposure leads to oxidative damage in C. vulgaris. At these concentrations, chlorophyll and the structure of chloroplasts were destroyed.