Faculty Bibliography

A method for the analysis of perfluorinated compounds (perfluoroalkyl sulfonates: C4, C6, C8, C10; perfluoroalkyl sulfinates: C6, C8, C10; perfluorooctanesulfonamide, N-ethyl perfluorooctanesulfonamide, N-ethyl perfluorooctanesulfonamidoacetate, perfluorocarboxylates: C4-C14; fluorotelomer carboxylate (7:3, 8:2) in whole blood using acetonitrile and OASIS WAX solid phase extraction (SPE) cartridge was developed. Separation of target compounds in two HPLC columns (ion exchange JJ50-2D and C18 Betasil columns) was examined. Matrix recoveries of the developed methods ranged from 70% to 120%. Separation of possible inferences such as taurodeoxycholic acid (TDC) was accomplished using an ion exchange JJ50-2D column, and this separation was validated using whole blood of different animals.

Despite the reports of the occurrence of perfluorochemicals (PFCs) in industrialized nations, information on PFCs in less industrialized countries is meager. In the present study, concentrations and profiles of PFCs were investigated in surface waters (rivers, lakes, coastal seas and untreated sewage; n=42) including the Ganges River water, and biota such as shrimp (n=2), fish (n=28), and Ganges River dolphin (Platanista gangetica; n=15). PFOS was the dominant PFC found in most of the samples analyzed including water samples except untreated sewage (water: <0.04-3.91 ng L(-1); biota: 0.248-27.9 ng g(-1) ww). Long-chain (C11-C18) perfluorocarboxylates (PFCAs) were not detected in the water samples (<0.2 ng L(-1)), although PFDA (0.061-0.923 ng g(-1) ww) and PFUnDA (0.072-0.998 ng g(-1) ww) were found in biological samples The arithmetic mean PFOS concentration found in the liver of Ganges River dolphin was 27.9 ng g(-1) ww. Bioconcentration and biomagnifications factors of PFCs were estimated in the Ganges River basin food web. The highest concentration of PFOA, 23.1 ng L(-1), was found in untreated sewage samples. Overall, concentrations of PFCs of water and biological samples from India are lower than the concentrations reported for other countries so far. PFC profiles in Indian waters are dominated by PFOS, followed by PFOA, which is different from the pattern reported for other countries such as Korea, Japan and USA, where PFOA was the predominant compound in waters. The flux estimates for PFOS, PFOA and PFNA from the Ganges River in India to the Bay of Bengal were in the range of several hundreds of kilograms per year.

Perchlorate (ClO(4)(-)), which is used as an oxidizer in jet and rocket fuels, pyrotechnic devices and explosives, is a widespread contaminant in surface waters and groundwater of many countries. Perchlorate is known to affect thyroid function. Despite the compound's widespread occurrence and potential health effects, perchlorate levels in drinking water in India are not known. In this study, water samples collected from 13 locations in six states (n=66), and saliva samples collected from four locations in three states (n=74) in India, were analyzed for perchlorate using high performance liquid chromatography interfaced with tandem mass spectrometry (HPLC-MS/MS). Perchlorate was detected in most (76%) of the water samples analyzed at concentrations above the quantitation limit of 0.02 microg L(-1); concentrations ranged from <0.02 to 6.9 microg L(-1) (mean: 0.42+/-1.1 microg L(-1); median: 0.07 microg L(-1)). Mean concentrations of perchlorate in drinking water, groundwater, bottled water, surface water and rain water were 0.1, 1.0, <0.02, 0.05 and <0.02 microg L(-1), respectively. From a total of 66 water samples analyzed, only three samples contained perchlorate levels above 1 microg L(-1); all three were groundwater samples. Perchlorate was found in the saliva samples analyzed at concentrations above 0.2 microg L(-1) and up to 4.7 microg L(-1) (mean: 1.3+/-1.3 microg L(-1); median: 0.91 microug L(-1)). No remarkable differences in perchlorate concentrations were found among the sampling locations of water or saliva or in subgroups stratified by gender or age. Perchlorate concentrations in water samples from India are one to two orders of magnitude lower than the concentrations reported for the United States.

Polybrominated diphenyl ethers (PBDEs) are a class of synthetic halogenated organic compounds used in commercial and household products, such as textiles, furniture, and electronics, to increase their flame ignition resistance and to meet fire safety standards. The demonstrated persistence, bioaccumulation, and toxic potential of these compounds in animals and in humans are of increasing concern. The oceans are considered global sinks for PBDEs, as higher levels are found in marine organisms than in terrestrial biota. For the past three decades, North America has dominated the world market demand for PBDEs, consuming 95% of the penta-BDE formulation. Accordingly, the PBDE concentrations in marine biota and people from North America are the highest in the world and are increasing. Despite recent restrictions on penta- and octa-BDE commercial formulations, penta-BDE containing products will remain a reservoir for PBDE release for years to come, and the deca-BDE formulation is still in high-volume use. In this paper, we review all available data on the occurrence and trends of PBDEs in the marine ecosystems (air, water, sediments, invertebrates, fish, seabirds, and marine mammals) of North and South America. We outline here our concerns about the potential future impacts of large existing stores of banned PBDEs in consumer products, and the vast and growing reservoirs of deca-BDE as well as new and naturally occurring brominated compounds on marine ecosystems.

Seven species of teleost fishes comprising major prey of northwest Atlantic harbor seals were analyzed for polybrominated diphenyl ethers (PBDEs). PBDE concentrations in whole fish samples (n=87) were compared with those measured previously in harbor seal blubber to evaluate the transfer of PBDEs from prey to predator. Hexabromocyclododecane (HBCD) concentrations were measured in three fish species to provide an initial estimation of HBCD contamination in this ecosystem. HBCD was detected in 87% of the fish samples at concentrations ranging from 2.4 to 38.1 ng/g, lw (overall mean 17.2+/-10.2 ng/g, lw). SigmaPBDE concentrations in fish ranged from 17.9 to 94 ng/g, lw (overall mean 62+/-34 ng/g, lw). SigmaPBDE concentrations in the harbor seals were two orders of magnitude higher than levels in the fish. Biomagnification factors (BMFs) from fish to seals averaged from 17 to 76, indicating that tetra- to hexa-BDEs are highly biomagnified in this marine food web. BDE-47 was the dominant congener in all samples, suggesting exposure to the penta-BDE mixture. The presence of higher brominated congeners including BDE-209 at measurable levels in fish and seal tissue, along with the very high biomagnification of BDE-153, as well as -155, and -154, suggests recent exposure to the octa- and deca-BDE formulations in this US coastal marine food web, as well as the additional contribution of BDE-209 debromination in fish to the loading of persistent PBDEs in the seals. This is the first study to report the occurrence of BDE-209 and other higher BDEs in commercially important marine fishes from the northwest Atlantic.

Two sediment cores, one at middle of the bay (core 1) and another at an outfall of a wastewater treatment plant (WWTP; core 2) were collected in Masan Bay, Korea, to investigate the historical records of contamination by polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and nonylphenols (NPs). Vertical profiles of PCDD/Fs, dl-PCBs, and NPs in the two cores, dated using (210)Pb technique, were different but they had similar vertical profiles within the same core. The overall concentrations of these contaminants were greater in core 2 (0.05-110ng TEQkg(-1) dry wt for PCDD/Fs; 0.02-4.4ng TEQkg(-1) dry wt for dl-PCBs; 1.0-470microgkg(-1) dry wt for NPs) than in core 1 (0.72-8.0ng TEQkg(-1) dry wt for PCDD/Fs; 0.03-1.4ng TEQkg(-1) dry wt for dl-PCBs; 1.3-110microgkg(-1) dry wt for NPs). In particular, PCDD/F concentrations in core 2 were an order of magnitude greater than the concentrations in core 1. The highest concentrations of all target contaminants in cores1 and 2 were found at the surface layer (dated as 2005) and at 8-10cm ( approximately 2000), respectively. For sediment core 2, rapid changes in the concentrations and sources of target contaminants coincide with the establishment and operation of a WWTP; this suggested that discharges from WWTP contributed to contamination by PCDD/Fs, dl-PCBs and NPs in the bay. Analysis of data by non-parametric multidimensional scaling ordination showed that both the cores were influenced by different PCDD/F sources over time. Inventories and fluxes of PCDD/Fs, dl-PCBs, and NPs have rapidly increased since establishment of the WWTP, indicating that the discharge of WWTP is an important source of sediment contamination in aquatic environment.

Perfluorinated chemicals (PFCs) have been detected in abiotic and biotic matrices worldwide, including the Arctic Ocean. Considering these chemicals' persistent and bioaccumulative potentials, it was expected that levels of PFCs, like those of many legacy organic pollutants, would respond slowly to the restrictions in production and usage. Temporal trend studies in remote areas, such as the Arctic, can help determine the chronology of contamination and the response of the environment to regulations on PFCs. Prior to this study, temporal trends of PFCs in Alaskan coastal waters had not been examined. In the present study, concentrations of six PFCs were determined in livers of northern sea otters (Enhydra lutris kenyoni) collected from three areas in south-central Alaska (Prince William Sound, n = 36; Resurrection Bay, n = 7; Kachemak Bay, n = 34) from 1992 to 2007. Additionally, previously published profiles and concentrations of PFCs in southern sea otters from California and Asian sea otters from Kamchatka (Russia) were compared to our new data, to determine the geographical differences in PFC profiles among these three regions in the Pacific Ocean. Perfluorooctanesulfonate (PFOS), perfluorooctanesulfonamide (PFOSA), and perfluorononanoate (PFNA) were the predominant PFCs found in the livers of northern sea otters from 1992 to 2007. Other PFCs, such as perfluorooctanoate (PFOA), perfluoroundecanoate (PFUnDA), and perfluorodecanoate (PFDA), were detected less frequently, and at low concentrations. Overall, from 2001 to 2007, a decrease in concentrations of PFOS was found in northern sea otters, suggesting an immediate response to the phase-out in 2000 of perfluorooctanesulfonyl-based compounds by a major producer in the United States. In contrast, concentrations of PFNA in northern sea otters increased by 10-fold from 2004 to 2007. These results indicate that the contribution by PFNA to SigmaPFC concentrations is increasing in northern sea otters. The profiles (i.e., composition of individual PFC to SigmaPFC concentration) of PFCs in northern sea otters from Alaska were similar to those reported for southern sea otters from California, but were considerably different from the profiles reported for Asian sea otters from Russia, suggesting differences in point sources of exposure.

Chlorinated and brominated polycyclic aromatic hydrocarbons (CIPAHs and BrPAHs) occur as pollutants in the environment. Nevertheless, there is little information available regarding the toxic effects of CIPAHs and BrPAHs. The potencies of 19 individual ClPAHs and 11 individual BrPAHs to induce aryl hydrocarbon receptor (AhR)-mediated activities (i.e., dioxin-like toxicity), relative to the potency of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), were determined in vitro by use of a recombinant rat hepatoma cell (H4IIE-luc) assay. Several CIPAHs elicited AhR-mediated activity; the relative potencies (RePs) of 6-monochlorochrysene, and 7-monochlorobenz[a]anthracene were 2.6 x 10(-5) and 6.3 x 10(-6), respectively. Among BrPAHs, 7-monobromobenz[a]anthracene and 4,7-dibromobenz[a]anthracene had the highest RePs, 2.1 x 10(-5) and 2.3 x 10(-5), respectively. None of the chlorinated or brominated anthracene or fluorene compounds elicited AhR-mediated activity atthe concentrations tested. We developed a structure-activity relationship for AhR-mediated potencies of CIPAHs.The RePs of ClPhe and ClFlu (low-molecular-weight ClPAHs) were directly proportional to the compounds' degrees of chlorination. The RePs of higher-molecular-weight ClPAHs (> or = 4-rings) were lower than those of the corresponding parent PAHs. The RePs of BrPAHs were higher than the RePs of the corresponding ClPAHs. For instance, 6-BrBaP was more potent than 6-ClBaP and 7-BrBaA was more potent than 7-ClBaA. The RePs determined in this study were applied to literature concentrations of Cl- and Br-PAHs in environmental samples, to calculate dioxin-like toxicities, as toxic equivalents (TEQs). The TEQs of ClPAHs calculated using the concentrations of individual ClPAHs were 4.6 pg-TEQ/g in fly ash, 0.015 fg-TEQ/m3 in automobile exhaust, and 0.085 fg-TEQ/m3 in urban air. 6-ClChr accounted for 80% of the total ClPAHs-TEQs in fly ash. This is the first in vitro study to report AhR-mediated activities of Cl- and Br-PAHs relative to the activity of TCDD.

The widespread occurrence and environmental persistence of perfluorinated compounds (PFCs) received worldwide attention recently. Exhaustive analysis of all fluorinated compounds in an environmental sample can be daunting because of the constraints in the availability of analytical standards and extraction methods. Combustion ion chromatographic technique for trace fluorine analysis was used to assess the concentrations of known PFCs (e.g., PFOS, PFOA) and total fluorine (TF) in the blood of wild rats collected from Japan. The technique was further validated using tissues from PFOA-exposed rats. Six PFCs (PFOS, PFOSA, PFUnDA, PFDA, PFNA, and PFOA) were detected in all of the wild rat blood samples. Concentrations of extractable organic fluorine (EOF) in fraction 1 (Fr1; MTBE extraction) of wild rats ranged 60.9-134 ng F mL(-1), while those in fraction 2 (Fr2; hexane) were below LOQ (32 ng F mL(-1)); TF concentrations in the blood of wild rats ranged from 59.9-192 ng F mL(-1). The contribution of known PFCs in EOF-Fr1 (MTBE) varied from 9% to 89% (56% on average), and known PFC concentrations in TF content were less than 25%. In contrast, TF concentrations in the blood of PFOA-exposed rats ranged from 46900 to 111,000 ng F mL(-1), with PFOA contributing over 90% of TF. A comparison of results from the samples analyzed in this study and the literature revealed three distinct groups with PFOA/known PFC and TF levels (i.e., wild rats and general population, occupationally exposed workers, and PFOA-exposed laboratory rats). The mass balance analysis of the different forms of fluorine in blood suggested the presence of other forms of organic fluorine in addition to known PFCs.

Polychlorinated naphthalenes (PCNs) are persistent, bioaccumulative, and toxic contaminants. Prior to this study, the occurrence of PCNs in human adipose tissues from the USA has not been analyzed. Here, we have measured concentrations of PCNs in human adipose tissue samples collected in New York City during 2003-2005. Concentrations of PCNs were in the range of 61-2500pg/g lipid wt. in males and 21-910pg/g lipid wt. in females. PCN congeners 52/60 (1,2,3,5,7/1,2,4,6,7) and 66/67 (1,2,3,4,6,7/1,2,3,5,6,7) were predominant, collectively accounting for 66% of the total PCN concentrations. Concentrations of PCNs in human adipose tissues were 2-3 orders of magnitude lower than the previously reported concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Concentrations of PCNs were not correlated with PCB concentrations. The contribution of PCNs to dioxin-like toxic equivalents (TEQs) in human adipose tissues was estimated to be <1% of the polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F)-TEQs.