Oxidative Stress in Laboratory-Incubated Double-Crested Cormorant Eggs Collected from the Great Lakes

Double-crested cormorant (Phalacrocorax auritus) eggs were collected in 1998 from three sites on Lakes Huron and Superior and either analyzed for 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD)-like residues or artifically incubated. Some of the incubated eggs were injected with vitamin E (antioxidant) or piperonyl butoxide (CYPIA blocker) to examine the role of CYPIA and oxidative stress in normal bird development. Embryos (day 23) were analyzed for hepatic ethoxyresorufin O-deethylase (EROD) activity and different measures of oxidative stress. Glutathione-related parameters were also measured in brain. In contrast to the historical data, there were no statistically significant differences in concentrations of chlorinated dioxins, furans, dioxin-like PCBs, or total TCDD-equivalents (TEQs) in eggs among sites. Survival and incidence of abnormalities were comparable at all study sites. Slight differences in liver, heart, and egg weight were observed among sites. A greater incidence of eye deformities was observed in embryos treated with vitamin E. Treatment with the CYPIA blocker, piperonyl butoxide, decreased the body weights of embryos. EROD activities were similar at all locations, but measures of oxidative stress varied among locations. There were greater levels of oxidized glutathione and oxidative DNA damage at Little Charity Island in Saginaw Bay. There was relatively great interindividual variation in biochemical responses and significant interrelation of the parameters of oxidative stress. While exposure to PCDD/DF and PCBs does not seem to explain the observed oxidative stress, the potential of these compounds to cause the observed effects can not be completely excluded.     

Organochlorine concentrations in Laurentian Great Lakes salmonines: Implications for fisheries management

To assess species-specific differences in organochlorine (OC) concentrations and sport harvest of Lake Michigan salmonines, and how this may affect human exposure to OC compounds, creel survey and OC analysis data for salmon and trout collected from the western waters of Lake Michigan in 1985 and 1990 were examined. In all species, total concentrations of polychlorinated biphenyls (PCBs) attained the highest concentration of the OC compounds quantified in both study years. DDT and metabolites attained the second highest concentration of OC compounds, in those species in which these compounds were quantified, followed by chlordane and its constituents and dieldrin, respectively. The relative concentrations of PCBs and OC pesticides remained constant between study years in all species, except for brook trout as limited 1990 data prevented analysis. For the mean lengths of each species of salmonines taken by anglers in 1985, lake trout showed the highest concentrations of OC compounds followed by brown trout, chinook salmon, brook trout, rainbow trout, and coho salmon, respectively. In 1990 lake trout again had the highest concentration of OCs followed by chinook salmon, brown trout, rainbow trout, and coho salmon. Brook trout were not in the analysis. Chinook salmon contributed the greatest proportion of OCs to the 1985 sport catch because of its dominance in total biomass of fish harvested. Lake trout contributed the greatest proportion of OCs to the 1990 sport catch, although the second highest in biomass harvested, because of the higher concentration of OC compounds in this species. The concentrations of PCBs declined between study years in all species except brook trout becaused limited 1990 data prevented this comparison. Study results indicate salmonine stocking policies can significantly influence the exposure of sport fish consumers in the Great Lakes region to OC compounds.     

Dietary Intakes and Plasma Organochlorine Contaminant Levels among Great Lakes Fish Eaters

Nutritional intakes and contaminant burdens should be assessed jointly in individuals who are at high risk of environmental exposures to contaminants through food. In this study, the authors used shore surveys and community contacts to recruit 91 individuals who frequently consumed Great Lakes fish. These individuals provided dietary intake information and fasting blood samples for lipid and contaminant analyses. Participants ate an annual median of 88 meals of Great Lakes fish. Asian-Canadians consumed more total fish meals (i.e., Great Lakes, non-Great Lakes, and other) (medians = 213.0 females, 223.0 males) than Euro-Canadians (medians = 131.0 females, 137.5 males). The higher total fish consumption by Asian-Canadians was associated with a lower percentage of energy derived from fat, higher protein and iron intakes, and higher plasma concentrations of omega-3 essential fatty acids (e.g., median docosahexaenoic acid levels [μg/l] in Asian-Canadian females = 5.48, males = 4.38; in Euro-Canadian females = 2.93, males = 2.27). Plasma organochlorine contaminant lipid weight concentrations varied by country of origin and by gender (e.g., median total polychlorinated biphenyls [μg/kg] in Asian-Canadian females = 490.6, males = 729.0; in Euro-Canadian females = 339.6, males = 355.5). Age was the most consistent predictor (+ve) of contaminant concentrations, followed by years spent in Canada (for Asian-Canadians). Associations with sport fish consumption variables were less consistent than for the aforementioned predictors. Given both the health benefits and potential risks of fish consumption, policies that address diverse ethnocultural groups should support continued consumption of sport fish, but from less-contaminated sources than are currently used.     

Organochlorine Exposure and Incidence of Diabetes in a Cohort of Great Lakes Sport Fish Consumers

Background

Studies have demonstrated ubiquitous human exposure to persistent organic pollutants (POPs) such as p,p′-diphenyldichloroethene (DDE) and polychlorinated biphenyls (PCBs). Although there is considerable evidence that POP exposures are associated with prevalent diabetes, these studies do not establish causality because the cross-sectional study design does not allow for assessment of temporality of the exposure–disease association. Prospective studies, however, have been lacking.

Objectives

This study was designed to determine whether POP body burdens are related to incidence of diabetes in a cohort of Great Lakes sport fish consumers.

Methods

The cohort was established in the early 1990s and followed through 2005. We tested serum for DDE and PCB congeners and assessed diabetes diagnosis, demographics, and fish consumption. Associations of diabetes with exposures were examined prospectively in participants without diabetes in 1994–1995, followed through 2005. Annual percent changes in DDE and PCB-132/153 from 1994 to 2005 were examined by diabetes status.

Results

DDE exposure was associated with incident diabetes. Incident diabetes was not associated with mono-ortho PCB-118, total PCBs, or years of sport fish consumption. Annual percent change in DDE and PCB-132/153 did not differ significantly by diabetes status.

Conclusions

This study demonstrates an association between DDE exposure and incident diabetes. The findings of an association of DDE with incident diabetes and the lack of effect of diabetes on annual percent change in POPs do not support the hypothesis that associations of POPs with diabetes are attributable to reverse causality. Additional studies should address the biological pathways by which DDE could affect glucose homeostasis.     

Mercury concentrations in fish from Canadian Great Lakes areas of concern: an analysis of data from the Canadian Department of Environment database

The tissue mercury concentrations in six species of fish collected at the 17 Areas of Concern identified by the International Joint Commission on the Canadian side of the Great Lakes were analyzed using an Environment Canada database. A linear increase in mercury concentration with fish length was found, but slopes differed among locations. The temporal pattern over the period 1971-1997 differed across species in fish collected in Lake St. Clair; in at least two species there was evidence of increased mercury concentration during the 1990s that had been suggested in an earlier analysis. Areas of Concern differed significantly in observed tissue concentrations. Differences observed did not consistently parallel expectations associated with the historical presence of chlor-alkali plants in the vicinities of some locations. An attempt to correlate the fish tissue mercury concentration with the frequency of occurrence of infantile cerebral palsy at Areas of Concern was unsuccessful.     

Polychlorinated Dibenzo-p-Dioxins (PCDDs) and Dibenzofurans (PCDFs) in Muscle and Eggs of Salmonid Fishes from the Great Lakes

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in dorsal muscle and eggs of coho salmon, lake trout, and chinook salmon collected from Lakes Superior, Michigan, and Huron (Michigan waters). Absolute and relative concentrations of PCDDs and PCDFs varied among sampling locations (inter- and intralake) and fish species. Fish collected from Bay City (Saginaw Bay) contained the greatest concentrations of PCDDs and PCDFs both in muscle and eggs. Among the three fish species, chinook salmon accumulated greater concentrations than did coho salmon or lake trout. Concentrations of PCDFs were greater than those of PCDDs in all fishes. OCDF and TCDF were the predominant congeners of PCDF, whereas OCDD and TCDD concentrations predominated in PCDDs. Homolog compositions of PCDDs and PCDFs suggested the existence of multiple local sources in various locations. Concentrations of PCDDs and PCDFs in eggs of fishes were significantly correlated with those in muscle. Received: 2 May 1998/Accepted: 20 December 1998     

Contaminants in fish from Great Lakes Harbors and Tributary mouths

Composite fish samples collected from Great Lakes Harbors and Tributaries between 1980 and 1981 were analyzed by gas chromatography and gas chromatography-mass spectrometry for a wide range of pesticides and priority pollutants. Severe polychlorobiphenyl (PCBs) contamination was observed in Sheboygan River fish with moderate to severe PCB contamination in samples from the Milwaukee, Kinnickinnic, Fox, and Ashtabula Rivers. The Ashtabula River samples also contained several chlorinated aromatic and aliphatic hydrocarbons. Polynuclear aromatic hydrocarbons were detected in fish from the Black, Kinnickinnic and Menominnee Rivers, while a number of benzene derivatives were observed in samples from the Fox and Wolf Rivers.     

Assessing Canadian inventories to understand the environmental impacts of mercury releases to the Great Lakes region

North American pollutant release and transfer registries have been continuously developing with an eye to understanding source/receptor relationships and ensuring that the polluter-paid principle is applied to the appropriate parties. The potential contribution of mercury to the Great Lakes Basin arising from the rerelease of historic mercury pollution from contaminated aquatic and terrestrial media is poorly understood and the subject of concern. Although a considerable amount of data may be available on the atmospheric component of mercury releases to the Basin, further inventory work is needed to quantify the rerelease of the historic mercury. Much of the related existing inventory information is either not derived from direct measurement or not bounded by a mass-balance accounting. Critical to this determination is an increased confidence in the inventories of mercury from past and current practices. This may be enhanced through comprehensive and thorough surveys of contributions from specific products and their life-cycle assessments. An even greater challenge is to determine the bioavailability of the mercury emanating from land-based sources and from aquatic media. This paper describes the interplay among the sources and receptors of mercury and provides a quantitative assessment of current Canadian contributions of mercury as a contaminant to the Great Lakes. Recommendations for improved assessments are provided.     

A Comparison of Mercury Levels in Feathers and Eggs of Osprey (Pandion haliaetus) in the North American Great Lakes

Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three “naturally formed” lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991–1994. Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from chicks (approximately 28–35 days old) appear to be better indicators of local contaminant conditions since spatial patterns of mercury in known prey, yellow perch (Perca flavescens), also collected in these areas, were more similar to chick feathers than to eggs. Mercury levels were less variable in chick feathers than in eggs. Estimates of biomagnification factors using prey of known size at these areas were also less variable in feathers than in eggs. At naturally formed lakes, no significant correlation in mercury levels between eggs and chick feathers from the same nest was apparent, suggesting that the source of mercury contamination was not the same in these two tissues: mercury levels in eggs reflect mercury acquired on the breeding grounds, wintering grounds, and migratory route; mercury levels in chick feathers reflect local dietary conditions on the breeding grounds. Mercury levels in both osprey eggs and chick feathers were higher at the Ogoki Reservoir than at naturally formed lakes. Adult osprey feathers had higher mercury concentrations than chick feathers. Mercury levels in osprey eggs, chick feathers, and adult feathers did not approach levels associated with toxic reproductive effects. Received: 1 December 1996/Accepted: 16 April 1997     

Analysis of UNEP Priority POPs Using HRGC-HRMS and Their Contamination Profiles in Livers and Eggs of Great Cormorants (Phalacrocorax carbo) from Japan

The present investigation demonstrates establishment of United Nations Environment Programme (UNEP) priority Persistent Organic Pollutants (POPs) using high-resolution gas chromatography–high-resolution mass spectrometry. Particularly, POPs analytical methods were established using native and ¹³C-labeled internal standards of HCHs, HCB, cyclodienes, chlordanes, DDTs, mirex, dioxin-like PCBs, PCDDs, and PCDFs by isotope dilution technique. The relative response factor for 6-point calibration curve native standards (18 replicate analysis) were in the ranges of 0.93–1.43 with relative standard deviation ranges from 1.68 to 4.96%. Instrument detection limit and instrument quantification limit was established for various POPs at femtograms. Concentrations of UNEP-POPs were measured in liver (n = 10) and egg (n = 10) of great cormorants and their major diet, gizzard shad (n = 2), collected in and around Tokyo, Japan. DDTs (ranges in liver and egg, respectively) were predominant accumulants (9800–310,000 and 9600–73,000) followed by dioxin-like PCBs (4500–69,000 and 7900–150,000), chlordanes (2600–16,000 and 700–4,800), cyclodienes (650–4600 and <1–1000), HCB (680–2800 and 180–590), HCHs (230–1800 and 120–490), PCDD/DFs (3.2–27 and 1.7–5.7) on nanogram per gram lipid basis. Concentrations (ranges) of POPs in gizzard shad were in the following order: DDTs (3900–16,000), chlordanes (3400–14,000), cyclodienes (340–1300), HCB (110–480), and HCHs (140–360) on nanogram per gram lipid basis.     

Organochlorine Pesticides and Polychlorinated Biphenyls (PCBs) in Sediments and Biota from Four US Arctic Lakes

Organochlorine (OC) concentrations in surface sediment, snails (Lymnea sp.), and two freshwater fish species (grayling, Thymallus arcticus; and lake trout, Salvelinus namaycush) from four lakes in the US Arctic were determined. In surface sediment, chlorinated benzenes (including hexachlorobenzene, HCB), and p,p′-DDT were the primary analytes detected (max = 0.7 ng/g dry wt), while individual polychlorinated biphenyl (PCB) congeners were always below 0.1 ng/g. A wider range of compounds and higher concentrations were found in lake trout, the top predatory fish species in the same lakes. The concentration ranges for hexachlorocyclohexanes (HCHs), chlordane-related compounds (CHLORs), DDTs, and PCBs in lake trout and grayling were similar to those reported for other arctic freshwater fish (1–100 ng/g wet wt), but one to two orders of magnitude lower than Great Lakes salmonids. Nitrogen isotope analysis confirmed that differences in OC concentrations between grayling and lake trout are explained partly by differences in food web position. Received: 30 August 1996/Accepted: 24 July 1997     

Fish consumption and advisory awareness in the Great Lakes Basin

More than 61 million adults live in the eight U.S. states bordering the Great Lakes. Between June 2001 and June 2002, a population-based, random-digit-dial telephone survey of adults residing in Great Lakes (GL) states was conducted to assess consumption of commercial and sport-caught fish and awareness of state-issued consumption advisories for GL fish. On the basis of the weighted survey data, approximately 84% of the adults living in these states included fish in their diets. Seven percent (an estimated 4.2 million adults) consumed fish caught from the Great Lakes. The percentage of residents who had consumed sport-caught fish (from any water source) varied regionally and was highest among those who lived in Minnesota (44%) and Wisconsin (39%). Consumption of GL sport fish was highest among residents of Michigan (16%) and Ohio (12%). Among residents who had eaten GL fish, awareness of consumption advisories varied by gender and race and was lowest among women (30%) and black residents (15%). However, 70% of those who consumed GL sport-caught fish twice a month or more (an estimated 509,000 adults across all eight states) were aware of the advisories. Findings from this survey indicate that exposure to persistent contaminants found in GL fish is likely limited to a relatively small subpopulation of avid sport-fish consumers. Results also underscore the public health importance of advisories for commercial fish because an estimated 2.9 million adults living in these states consume more than 104 fish meals per year and may be at risk of exceeding the reference doses for methylmercury, polychlorinated biphenyls, and other bioaccumulative contaminants.