Relationship of microbial activity andCeriodaphnia responses to mining impacts on the Clark Fork River,Montana

An evaluation of an aquatic toxicity test battery was conducted on the metal polluted Clark Fork River, in western Montana. The test battery included the 7-dayCeriodaphnia survival-reproduction assay and 12 microbial assays of enzyme activity, heterotrophic uptake, and metal resistance in sediments and/or waters. Surrogate tests were evaluated for effectiveness at detecting toxicant impacts by comparing their response with stream parameters, including diatoms and metal concentrations. Several statistically significant correlations were observed between surrogate profiles and stream profiles, which verified toxicant impacted areas of the stream. The short-term test battery proved to be valid and allowed evaluation of impacts to both periphyton and microbial processes.     

Contaminants in Ospreys from the Pacific Northwest: II. Organochlorine Pesticides, Polychlorinated Biphenyls, and Mercury, 1991–1997

Eggs of ospreys (Pandion haliaetus) were collected over the period 1991 to 1997 at 111 nests in the Fraser and Columbia River drainage systems of British Columbia, Washington, and Oregon. Contents were analyzed for organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and total mercury. Blood samples were taken from nestling ospreys at two time points during the 1992 breeding season on the Thompson River and analyzed for non-ortho PCBs. Concentrations of DDE and related compounds showed high variability among individual eggs within study areas and no significant differences in mean concentrations among study areas. Some eggs contained high concentrations of DDE, up to 20 mg/kg (wet weight), for which there were no evident local sources, suggesting that exposure occurred outside of the breeding grounds. Most other OC pesticides measured in osprey eggs showed a similar distribution, although mean concentrations of chlordane-related compounds were generally, and in some cases significantly, higher in samples collected from the Columbia River sites compared to elsewhere. Significantly greater concentrations of PCBs were found in eggs from the Columbia River basin compared to the Fraser. This was attributed to extensive development of hydroelectric generation and related industries on the Columbia system. Significant differences among sites were also found in the pattern of PCB congeners, e.g., eggs from the lower Columbia River site had proportionally greater concentrations of less chlorinated, Aroclor 1242–type PCBs compared to other sites. In contrast, eggs from upper reaches of the Columbia River had relatively greater amounts of Aroclor 1254 and 1260 congeners. Mercury concentrations in osprey eggs tended to be uniform among sites and comparable to those reported in the literature for ospreys nesting on naturally formed lakes and rivers. There were no significant temporal changes in mean concentrations of any of the measured compounds at sites monitored from 1991 to 1997. Received: 24 August 1998/Accepted: 26 January 1999     

Mercury and Selenium Concentrations in Biofilm, Macroinvertebrates, and Fish Collected in the Yankee Fork of the Salmon River, Idaho, USA, and Their Potential Effects on Fish Health

The Yankee Fork is a large tributary of the Salmon River located in central Idaho, USA, with an extensive history of placer and dredge-mining activities. Concentrations of selenium (Se) and mercury (Hg) in various aquatic trophic levels were measured in the Yankee Fork during 2001 and 2002. Various measurements of fish health were also performed. Sites included four on the mainstem of the Yankee Fork and two off-channel sites in partially reclaimed dredge pools used as rearing habitat for cultured salmonid eggs and fry. Hg concentrations in whole mountain whitefish and shorthead sculpin ranged from 0.28 to 0.56 μg/g dry weight (dw), concentrations that are generally less than those reported to have significant impacts on fish. Biofilm and invertebrates ranged from 0.05 to 0.43 μg Hg/g dw. Se concentrations measured in biota samples from the Yankee Fork were greater than many representative samples collected in the Snake and Columbia watersheds and often exceeded literature-based toxic thresholds. Biofilm and invertebrates ranged from 0.58 to 4.66 μg Se/g dw. Whole fish ranged from 3.92 to 7.10 μg Se/g dw, and gonads ranged from 6.91 to 31.84 μg Se/g dw. Whole-body Se concentrations exceeded reported toxicological thresholds at three of four sites and concentrations in liver samples were mostly greater than concentrations shown to have negative impacts on fish health. Histological examinations performed during this study noted liver abnormalities, especially in shorthead sculpin, a bottom-dwelling species.     

Mercury Concentrations in Muscle and Liver Tissue of Fish from Marshes Along the Magdalena River,Colombia

The present research determined the total mercury concentrations in muscle and liver tissue in fish collected from the Magdalena River watershed. A total of 378 muscle samples and 102 liver samples were included in the analysis. The highest mean mercury level in muscle tissue was found in the noncarnivore, Pimelodus blochii. However, as a group, carnivores had significantly higher (p < 0.05) mercury levels in their muscle tissue than noncarnivores. A significant correlation (p < 0.05) was obtained between fish mass and mercury concentrations in muscle or liver in four species. No differences were observed in total mercury concentration based either on species or gender.     

Outdoor Air PCB Concentrations in Three Communities Along the Upper Hudson River,New York

Outdoor air polychlorinated biphenyl (PCB) concentrations were measured in upstate New York as part of a nonoccupational exposure investigation. The adjacent study communities of Hudson Falls and Fort Edward contain numerous sites of current and former PCB contamination, including two capacitor-manufacturing facilities. Outdoor air PCB concentrations in the study municipalities were significantly higher than in the comparison municipality of Glens Falls. Total PCB concentrations in the study area ranged from 0.102 to 4.011 ng/m³ (median: 0.711 ng/m³). For the comparison area, concentrations ranged from 0.080 to 2.366 ng/m³ (median: 0.431 ng/m³). Although our sampling was not designed to identify point sources, the presence of PCB-contaminated sites in the study area likely contributed to this observed difference in concentration. While elevated relative to the comparison area, total PCB concentrations in the study area are lower than those in other communities with known PCB-contaminated sites, and similar to levels reported in other locations from the northeastern United States.     

Phytoxicity of smelter-impacted soils in southwest Montana, USA

A century of copper smelting in southwest Montana, USA, destroyed vegetation for many kilometers surrounding the Washoe Smelter. Once the vegetation was lost, exposed soils were subject to wind and water erosion, which removed topsoil and left soil surfaces paved with gravel. A greenhouse study was conducted using soils from smelter-impacted and non-smelter-impacted sites near Anaconda, Montana. Bluebunch wheatgrass, Agropyron spicatum (Pursh) Scribn., and western yarrow, Achillea lanulosa Nutt., were grown for 50 d in unamended, fertilized, or limed treatments to determine if soil fertility, pH, or trace elements were limiting plant growth on soil from the impacted site. The addition of fertilizer significantly increased plant biomass of both species in soils from impacted and nonimpacted sites when compared to unamended and limed soil. The addition of lime had no effect on plant growth. When plant growth in fertilized smelter-impacted soil was compared to unamended nonimpacted soil, significantly more plant biomass was observed in the fertilized smelter-impacted soil. Shoot and root concentrations of trace elements were higher in plants grown in impacted soil compared to nonimpacted soil. The only element that was found to occur in concentrations reported to be phytotoxic was arsenic (As). However, toxicity thresholds for As, reported in the literature, were generated in agricultural species and do not likely have application to the native perennials used in this study.     

Indoor Air Polychlorinated Biphenyl Concentrations in Three Communities Along the Upper Hudson River,New York

Indoor air polychlorinated biphenyl (PCB) concentrations were measured in upstate New York as part of a nonoccupational exposure investigation. The adjacent study communities contain numerous sites of current and former PCB contamination, including two capacitor-manufacturing facilities. Indoor air PCB concentrations in the study area homes were not significantly different than in the comparison area homes. Total PCB concentrations in the study area homes ranged from 0.3 to 114.3 ng/m³ (median 7.9). For the comparison area homes, concentrations ranged from 0.3 to 233.3 ng/m³ (median 6.8). No correlations were found between PCB concentrations in indoor and outdoor air, with indoor concentrations generally 20 times higher than outdoor concentrations. Of the home characteristics cataloged, the presence of fluorescent lights was significantly associated with total PCB concentration in the study area only. The indoor PCB concentrations measured in this study are similar to those in other communities with known PCB-contaminated sites and similar to levels reported in other locations from the northeastern United States.     

Use of Artificial Stream Mesocosms to Investigate Mercury Uptake in the South River,Virginia, USA

Mercury is a globally distributed pollutant that biomagnifies in aquatic food webs. In the United States, 4,769 water bodies fail to meet criteria for safe fish consumption due to mercury bioaccumulation. Although the majority of these water bodies are affected primarily by atmospheric deposition of mercury, legacy contamination from mining or industrial activities also contribute to fish consumption advisories for mercury. The largest mercury impairment in Virginia, a 130-mile stretch of the South and South Fork Shenandoah rivers, is posted with a fish-consumption advisory for mercury contamination that originated from mercuric sulfate discharges from a textile facility in Waynesboro, Virginia, between 1929 and 1950. Although discharges of mercury to the river ceased >60 years ago, mercury levels in fish remain greater than levels safe for human consumption. This is due to the continued cycling of historic mercury in the river and its eventual uptake and biomagnification through aquatic food webs. This study investigated the relative importance of waterborne versus sediment-borne mercury in controlling biological uptake of mercury into the aquatic food web. Twelve artificial stream channels were constructed along the contaminated South River in Crimora, Virginia, and the uncontaminated North River in nearby Port Republic, Virginia, to provide four experimental treatments: a control with no Hg exposure, a Hg in sediment exposure, a Hg in water exposure, and a Hg in sediment and water exposure. After 6 weeks of colonization and growth, algae in each treatment was collected and measured for mercury accumulation. Mercury accumulation in water-only exposures was four times greater than in sediment-only exposures and was equivalent to accumulation in treatments with combined water and sediment exposure. This indicates that mercury in the water column is much more important in controlling biological uptake than mercury in near-field sediments. As a result, future remediation efforts need to focus on strategies that either remove mercury from the water column or decrease flux to the water column.     

Concentrations and Hazard Assessment of Organochlorine Contaminants and Mercury in Smallmouth Bass from a Remote Lake in the Upper Peninsula of Michigan

Concentrations of PCBs, DDTs, toxaphene, chlordanes, dieldrin, and mercury were determined in smallmouth bass (Micropterus dolomieui) collected from Fumee Lake, a remote lake in the Upper Peninsula of Michigan. An ecological hazard assessment was conducted to determine potential impacts of contaminants on bald eagles and mink eating fish from this lake. Concentrations of organochlorines, except toxaphene, and mercury in smallmouth bass were similar to those found in fish from Lake Superior, where atmospheric inputs are the primary sources. Bioaccumulation was indicated by a positive correlation between fish weight and contaminant concentrations for organochlorines, while mercury concentrations did not appear to correspond predictably to body weight. Concentrations of mercury and PCBs in smallmouth bass were sufficiently great to be of concern regarding their consumption by eagles or mink. Received: 16 June 1997/Accepted: 11 August 1997     

Increased Mercury and Body Size and Changes in Trophic Structure of Gambusia puncticulata (Poeciliidae) Along the Almendares River, Cuba

The Almendares River is the largest river draining the area around Havana City, Cuba. The watershed is heavily populated and industrialized, which has had a significant impact on the flow and water quality of the river. The main goal of this study was to analyze the spatial variability in dietary habits, nutrient flow (using stable isotope ratios δ¹⁵N and δ¹³C), and mercury (Hg) levels along the Almendares River upstream and downstream of point-source discharges using localized fish Gambusia puncticulata. Stomach contents of G. puncticulata were similar among these sites. However, mean δ¹⁵N values ranged from 6 to 18 ‰ across sites and were lower in fish from downstream than upstream sites, suggesting localized influences of nutrient inputs along the river. δ¹³C values were between –22 and –25 ‰, except at a mid-basin site (–26 to –27‰), indicating that fish relied on similar carbon sources at most sites. Total mercury concentrations ranged from 0.04 to 0.49?μg/g wet weight whole body and were unrelated to the among-site differences in δ¹⁵N, but Hg exceeded the threshold considered to be protective of fish health (0.2?μg/g ww whole body) in the majority of fish from all sites but one. Results of this study indicate that although the dietary habits of this species do not vary across sites, tissue differences in δ¹⁵N, δ¹³C and Hg show little movement of this species among sites. Localized effects of human activities on nutrients and metals may be affecting the health of this species and posing a risk to other consumers in the ecosystem.     

Radiographic abnormalities and exposure to asbestos-contaminated vermiculite in the community of Libby, Montana, USA

Mining, handling, processing, and personal or commercial use of asbestos-contaminated vermiculite have led to widespread contamination of the Libby, Montana, area. We initiated a medical testing program in response to reports of respiratory illness in the community. The purpose of this analysis was to identify and quantify asbestos-related radiographic abnormalities among persons exposed to vermiculite in Libby and to examine associations between these outcomes and participants' self-reported exposures. A cross-sectional interview and medical testing were conducted in Libby from July through November 2000 and from July through September 2001. A total of 7,307 persons who had lived, worked, or played in Libby for at least 6 months before 31 December 1990 completed the interview. Of those, 6,668 participants > or = 18 years of age received chest radiographs to assess the prevalence of pleural and interstitial abnormalities. We observed pleural abnormalities in 17.8% of participants and interstitial abnormalities in < 1% of participants undergoing chest radiography. We examined 29 occupational, recreational, household, and other exposure pathways in the analysis. The prevalence of pleural abnormalities increased with increasing number of exposure pathways, ranging from 6.7% for those who reported no apparent exposures to 34.6% for those who reported > or = 12 pathways. The factors most strongly associated with pleural abnormalities were being a former W.R. Grace worker, being older, having been a household contact of a W.R. Grace worker, and being a male. In addition to being a former W.R. Grace worker, environmental exposures and other nonoccupational risk factors were also important predictors of asbestos-related radiographic abnormalities.     

Heavy Metal Concentrations in Northern Water Snakes (Nerodia sipedon) from East Fork Poplar Creek and the Little River, East Tennessee, USA

We compared the levels of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the blood, kidney, liver, muscle, and skin of northern water snakes (Nerodia sipedon) collected from the upper reach of East Fork Poplar Creek (EFPC) within the United States Department of Energy’s (USDOE’s) Y-12 National Security Complex with concentrations in tissues of northern water snakes from a reference reach of the Little River downstream from the Great Smoky Mountains National Park in East Tennessee. Our objectives were to determine whether concentrations of these metals were higher in tissues of water snakes collected from EFPC compared with the reference site and if northern water snakes were suitable bioindicators of metal contamination. Except for chromium, metal levels were significantly higher in tissues (kidney, liver, muscle, and skin) of EFPC northern water snakes compared with those in tissues of snakes from the reference site. Although female northern water snakes were significantly larger than male snakes, their tissues did not contain significantly higher metal concentrations compared with those from male snakes, possibly because of maternal transfer of metals to eggs. This study was the first to examine the accumulation of contaminants resulting from the operations of the USDOE’s Oak Ridge Reservation in snakes.     

Contaminants in Ospreys from the Pacific Northwest: I. Trends and Patterns in Polychlorinated Dibenzo-p-Dioxins and -Dibenzofurans in Eggs and Plasma

Osprey (Pandion haliaetus) eggs were collected from 1991 to 1997 at nests (n = 121) upstream and downstream of bleached kraft pulp mills and at reference sites in the Fraser and Columbia River drainage systems of British Columbia, Washington, and Oregon. Blood samples were collected from nestling ospreys during the 1992 breeding season on the Thompson River. Samples were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and -dibenzofurans (PCDFs). Mean concentrations of 2,3,7,8-TCDD were significantly higher in eggs collected in 1991 at downstream compared to upstream nests near pulp mills at Kamloops and Castlegar, British Columbia. There were no significant temporal trends in 2,3,7,8-TCDD, -TCDF or other measured compounds at a sample of nests monitored between 1991 and 1994 downstream of the Castlegar pulp mill, despite changes in bleaching technology (CIO₂ substitution). However, by 1997 concentrations of 2,3,7,8-TCDD and -TCDF were significantly lower than previous years in nests sampled downstream at both Castlegar and Kamloops. An unusual pattern of higher chlorinated PCDDs and PCDFs was found in many of the osprey eggs collected in this study, and considerable individual variation in the pattern existed among eggs from the same site. For example, eggs from four different nests at one study area (Quesnel) on the Fraser River had concentrations of 1,2,3,4,6,7,8-HpCDD ranging from <1 to 1,100 ng/kg and OCDD from <1 to 7,000 ng/kg wet weight. Higher mean concentrations of HpCDD and OCDD were found in eggs from the Thompson River, a tributary of the Fraser, compared to the Columbia River, and concentrations were generally higher at nests upstream of pulp mills. In plasma samples, 1,2,3,4,6,7,8-HpCDD and OCDD were the main compounds detected, with no significant differences measured between samples upstream versus downstream or earlier versus later in the breeding season. Use of chlorophenolic wood preservatives by lumber processors was considered the main source of higher chlorinated PCDD/Fs throughout the systems, based on patterns of trace PCDFs in eggs and significant correlations between egg concentrations of pentachlorophenol and both HpCDD (r = 0.891, p < 0.01) and OCDD (r = 0.870, p < 0.01). Received: 17 February 1998/Accepted: 11 June 1998     

Assessing the Bioaccumulation of Contaminants from Sediments of the Upper Mississippi River Using Field-Collected Oligochaetes and Laboratory-Exposed Lumbriculus variegatus

Concern with the redistribution of contaminants associated with sediment in the upper Mississippi River (UMR) arose after the flood of 1993. This project is designed to evaluate the status of sediments in the UMR and is one article in a series designed to assess the extent of sediment contamination in navigational pools of the river. Companion articles evaluate sediment toxicity and benthic community composition in navigation pools of the river. The objectives of the present study were to: (1) to assess the bioaccumulation of sediment-associated contaminants in the UMR using laboratory exposures with the oligochaete Lumbriculus variegatus, and (2) to compare bioaccumulation in laboratory-exposed oligochaetes to field-collected oligochaetes. Sediment samples and native oligochaetes were collected from 23 navigational pools on the Upper Mississippi River and the Saint Croix River. Contaminant concentrations measured in the L. variegatus after 28-day exposures to sediment in the laboratory were compared to contaminant concentrations in field-collected oligochaetes from the 13 pools where these sediments were collected. Contaminant concentrations were relatively low in sediments and tissues from the pools evaluated. Only polycyclic aromatic hydrocarbons (PAHs) and total polychlorinated biphenyls (PCBs) were frequently measured above detection limits. The majority of the biota-sediment-accumulation factors (BSAFs) for PAHs were within a range of about 1.0 to 2.6, suggesting that the theoretical BSAF value of 1.7 could be used to predict these mean BSAFs with a reasonable degree of certainty. A positive correlation was observed between lipid-normalized concentrations of PAHs detected in laboratory-exposed and field-collected oligochaetes across all sampling locations. Rank correlations for concentrations of individual compounds between laboratory-exposed and field-collected oligochaetes were strongest for benzo(e)pyrene, perylene, benzo(b,k)fluoranthene, and pyrene. About 90% of the paired PAH concentrations in laboratory-exposed and field-collected oligochaetes were within a factor of three of one another indicating laboratory results could be extrapolated to the field with a reasonable degree of certainty. Received: 6 July 1997/Accepted: 3 January 1998     

Assessment of autoimmune responses associated with asbestos exposure in Libby, Montana, USA

Systemic autoimmune responses are associated with certain environmental exposures, including crystalline particles such as silica. Positive antinuclear antibody (ANA) tests have been reported in small cohorts exposed to asbestos, but many questions remain regarding the prevalence, pattern, and significance of autoantibodies associated with asbestos exposures. The population in Libby, Montana, provides a unique opportunity for such a study because of both occupational and environmental exposures that have occurred as a result of the mining of asbestos-contaminated vermiculite near the community. As part of a multifaceted assessment of the impact of asbestos exposures on this population, this study explored the possibility of exacerbated autoimmune responses. Age- and sex-matched sets of 50 serum samples from Libby and Missoula, Montana (unexposed), were tested for ANA on HEp-2 cells using indirect immunofluorescence. Data included frequency of positive tests, ANA titers, staining patterns, and scored fluorescence intensity, all against known controls. Serum immunoglobulin A (IgA), rheumatoid factor, and antibodies to extractable nuclear antigen (ENA) were also tested. The Libby samples showed significantly higher frequency of positive ANA and ENA tests, increased mean fluorescence intensity and titers of the ANAs, and higher serum IgA, compared with Missoula samples. In the Libby samples, positive correlations were found between ANA titers and both lung disease severity and extent of exposure. The results support the hypothesis that asbestos exposure is associated with autoimmune responses and suggests that a relationship exists between those responses and asbestos-related disease processes.     

Negatives and Positives: Contaminants and Other Stressors in Aquatic Ecosystems

Published research is reviewed to provide examples of both positive and negative interactions of contaminants and: climate change; habitat change; invasive and introduced species; and, eutrophication including harmful algal blooms. None of these stressor interactions results solely in negative effects. Research must shift from examining contaminants or other stressors in isolation to considering potential positive and negative effects of interactions, with the ultimate goal of providing the necessary information for the effective management of ecosystem services.     

Polychlorinated Naphthalenes and Other Organochlorine Contaminants in Swedish Human Milk, 1972–1992

The concentrations of polychlorinated naphthalenes (PCNs) were determined together with polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), 1,1-bis-(4-chlorophenyl)-2,2,2-trichloroethane (p,p′-DDT), 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (p,p′-DDE) and hexachlorobenzene (HCB) in milk, sampled in the course of 1972–92 from mothers living in Stockholm. A previously developed method for multicomponent analysis of organochlorine environmental contaminants was adapted for simultaneous analysis of PCNs. The mean recoveries of seven chlorinated naphthalene (CN) congeners added to milk prior to extraction were 76–99%. Similar recoveries were obtained for the commercial PCN product Halowax 1014. The pattern of PCNs in milk differed to a great extent from that in the commercial PCN products. The dominating congeners in breast milk were 1,2,3,5,7-pentachloronaphthalene (CN-52), 1,2,3,4,6,7- and/or 1,2,3,5,6,7-hexachloronaphthalene (CN-66/CN-67) and one unidentified tetrachloronaphthalene. There was a notable decrease in the concentrations of PCNs as was of the other organochlorine contaminants in milk from 1972 to 1992. During this time period the sum of CN congeners decreased from 3,081 to 483 pg/g milk fat and the sum of toxic equivalents of dioxin and dioxin-like compounds decreased from 100 to 39 pg/g milk fat. Received: 5 June 1997/Accepted: 20 October 1997