Tracy L. Metcalfe

Effects of the antiandrogens, vinclozolin and cyproterone acetate on gonadal development in the Japanese medaka (Oryzias latipes)

This study was focused on determining the effects of exposure to antiandrogens on the gonadal development of Japanese medaka (Oryzias latipes). Test compounds included the fungicide, vinclozolin and the clinical antiandrogen, cyproterone acetate. Newly hatched medaka were exposed to aqueous solutions of vinclozolin (2500 microg/l) and the vinclozolin fungicide formulation, Ronilan (1000 and 5000 microg/l) and cyproterone acetate (1 and 10 microg/l), for 3 months. Histological evaluation of the gonadal tissues of exposed fish indicated that the 5000 microg/l concentration of the vinclozolin formulation (Ronilan) induced a low incidence of intersex (i.e. testis-ova) and the 2500 microg/l concentration of vinclozolin-affected spermatogenesis in males. Also, the vinclozolin treatments induced moderate ovarian atresia. Cyproterone acetate also induced a low incidence of testis-ova, but in contrast to the vinclozolin treatment the amount of ovarian tissue in the testis-ova was equal to or greater than the amount of testicular tissue. In the cyproterone acetate treatments, both oogenesis and spermatogenesis were moderately inhibited at all test concentrations. The results of this study indicate that antiandrogens have the potential to alter testicular development and gametogenesis in fish. However, research is needed to determine the mechanisms by which antiandrogens affect fish.

Polychlorinated biphenyls and organochlorine compounds in brain, liver and muscle of beluga whales (Delphinapterus leucas) from the Arctic and St. Lawrence estuary

Abstract Brain, liver and muscle samples from seven male beluga whales, Delphinapterus leucas , from Hendrickson Island in the Canadian Arctic ( n =3) and the St. Lawrence River estuary ( n =4), were analyzed for polychlorinated biphenyls (PCBs) and other organochlorine (OC) compounds to determine whether there are differences in the distribution of these contaminants in beluga tissues and between geographic locations. Wet weight concentrations of Σ PCB, Σ DDT, Σ chlordane and mirex were significantly higher ( p Σ hexachlorocyclohexane ( Σ HCH), primarily αHCH.

Semi-permeable membrane devices (SPMDs) for monitoring organic contaminants in the Otonabee River, Ontario

Abstract Semi-permeable membrane devices (SPMDs) were deployed for 4 weeks (May-June, 1994) at 8 sites in the Otonabee River, Ontario, Canada, and subsequently extracted for analysis of PCBs and polynuclear aromatic hydrocarbons (PAHs). The concentrations of PCBs were elevated in the SPMDs deployed in Little Lake at the upstream end of this system, which reflects continuing discharges and in-place PCB contamination in this urban area. However, at sites downstream from Little Lake, the concentrations of PCBs increased with distance downstream; indicating either another point-source of PCBs or spatial variations in the partitioning of these compounds into the dissolved phase. The spatial patterns for PAH contamination were similar to PCBs. At one site in Little Lake, SPMDs were collected at 2, 4 and 6 weeks after deployment and these temporal contaminant data are consistent with enhanced uptake ofPCBs and some hydrophobic PAHs as water temperature increased. These data indicate that SPMDs are useful in situ monitoring devices for determining spatial trends in the contamination of the aquatic environment, but several factors can modify rates of uptake into these devices.

PERSISTENT ORGANOCHLORINE COMPOUNDS IN THE BLUBBER OF RINGED SEALS (PHOCA HISPIDA) FROM THE BELCHER ISLANDS, NORTHWEST TERRITORIES, CANADA

Abstract Samples of blubber and morphometric data were obtained in 1991 from a population of ringed seals (Phoca hispida) located in southeastern Hudson Bay, near the Belcher Islands. Several PCB congeners, DDT and its metabolites, components of technical chlordane, HCH compounds, dieldrin and mirex were detected at concentrations below 150 ng/g lipid in the blubber of these animals. Female seals had lower concentrations of PCB congeners, DDT compounds and chlordane compounds in the blubber than male seals from this region, but there were no sex-specific differences observed for HCH compounds, dieldrin and mirex. Correlations were observed between the age of male seals and their estimated ‘blubber burdens’ (mg) of total PCBs and total DDT. There was evidence that the male seals from the Belcher Islands had higher concentrations and blubber burdens of total PCBs and lower concentrations of total HCHs than male seals sampled in 1989 from a population at Holman Island in the northwest Canadian arctic. Morphometric data indicated that the Holman Island seals were in better condition than the Belcher Islands seals at the time of sampling. Due to the negative correlation observed between contaminant concentrations in ringed seals and the condition of the animals, analysis of blubber burdens in seals may be a preferable method for monitoring spatial and temporal trends in the contamination of ringed seals in the arctic.

Levels and patterns of persistent organochlorines in minke whale (Balaenoptera acutorostrata) stocks from the North Atlantic and European Arctic

Regional variation in PCBs and organochlorine (OC) pesticide concentrations was examined using the blubber of 155 minke whales (Balaenoptera acutorostrata) sampled in seven regions in the North Atlantic and European Arctic, including western and southeastern Greenland, the Norwegian Sea, the North Sea and the Barents Sea. The levels and relative proportions of OCs were also used to examine the boundaries for North Atlantic minke whale stocks previously defined by the International Whaling Commission (IWC). Concentrations of major OC groups (sigmaPCB, 89.1-22 800 ng/g lipid; sigmaDDT, 65.3-6280 ng/g lipid; sigmaCHL, 33.3-2110 ng/g lipid) generally increased from west to east, while HCH concentrations (sigmaHCH, < 1-497 ng/g lipid) showed the opposite trend. Statistical comparison between six regions using sex-adjusted least squared mean concentrations showed that minke whales from the Barents Sea had significantly higher concentrations of EPCBs than those from the Vestfjorden/Lofoten, the North Sea, and west Svalbard, as well as significantly higher sigmaDDT concentrations compared to west Greenland animals. The differences in concentrations suggest that west and southeast Greenland minkes may represent one group of whales, which are distinct from both the Jan Mayen minkes and those from other IWC defined stocks in northern European waters. Principal components analysis using proportions of 71 PCB congeners and 20 OC pesticides (of total OCs) did not reveal any major differences among groups although minkes from the North Sea were distinguished from those from Greenland waters by higher loadings of more highly chlorinated PCBs and recalcitrant OC pesticides. The general similarity in mean levels of sigmaPCBs, sigmaDDT and sigmaCHL, as well as mean principal components analysis scores, among minkes sampled at Jan Mayen, Svalbard, Vestfjorden/Lofoten, the North Sea and the Barents Sea suggests that the whales are quite mobile and may feed in multiple areas within the northeastern Atlantic.

Detecting the transport of toxic pesticides from golf courses into watersheds in the precambrian shield region of ontario, canada

Golf courses impact the environment through alterations to habitat and through the release of nutrients and pesticides. The Precambrian Shield region of central Ontario, Canada, which is a major recreational area, is especially susceptible to the impacts of golf courses as a result of the geology and hydrology of the region. In a monitoring program at two golf courses in the Muskoka region conducted during the spring, summer, and fall of 2002, semipermeable membrane devices (SPMDs) were deployed into streams that drain the golf courses. The extracts from the SPMDs were tested for toxicity using bioassays with early life stages of an aquarium fish, the Japanese medaka (Oryzias latipes). Toxicity was assessed using a scoring system developed for the present study. The bioassays with medaka indicated that toxicity was highest in extracts from SPMDs deployed during the spring and the fall. The peaks in toxicity for the SPMDs deployed at the two golf courses corresponded with the presence in the SPMD extracts of pentachloronitrobenzene (PCNB) at concentrations up to 334 ng/SPMD. Quintozene is the turfgrass fungicide in which PCNB is the active ingredient. Pentachlorothioanisole, an anaerobic degradation product of PCNB, also was detected in the SPMDs deployed during the spring. Extracts prepared from SPMDs with high toxicity contained residues of a surfactant used in pesticide formulations, nonylphenol, at concentrations up to approximately 20 microg/SPMD. Overall, these data indicate that some pesticides applied to golf courses in the Precambrian Shield of central Ontario may have the potential to cause toxic impacts to aquatic organisms in adjacent watersheds.

Relative Concentrations of Cytochrome P450-Active Organochlorine Compounds in Liver and Muscle of Rainbow Trout From Lake Ontario

The teleost liver is the primary target organ for the induction of cytochrome P450-dependent monooxygenases by chemicals in fish. However, monitoring information on the residues of monooxygenase-inducing organochlorine compounds in fish generally consists of data on the concentrations in muscle tissue or the whole body. We determined the relative concentrations of cytochrome P450-active PCB congeners and organochlorine insecticides in the muscle and liver of rainbow trout (Oncorhynchus mykiss) sampled from the Ganaraska River on Lake Ontario. There were no significant differences in the mean concentrations of 24 PCB congeners in muscle and liver tissues when concentrations were expressed on a wet weight or a lipid weight basis. Of the 7 other potential cytochrome P450-active organochlorine compounds quantified, only dieldrin was present at significantly higher concentrations in muscle than liver samples, and endrin was present at significantly higher concentrations in liver than muscle. The demonstration of equivalent concentrations of most of these organochlorine compounds in liver and muscle suggests that data on contaminant levels in muscle may be used to evaluate the potential for induction of hepatic monooxygenases in salmonids.

Distribution of Toxic Organic Contaminants in Water and Sediments in the Detroit River

Abstract Contamination of sediments in the Detroit River has been shown to have impacts upon the health of benthic fish in direct contact with the sediments. It was hypothesized that hydrophobic contaminants partition from sediments into the aqueous phase in the Detroit River, subsequently bioaccumulating in fish and causing toxic effects. In order to assess the distribution of organic contaminants dissolved in water relative to contamination in the sediments, semi-permeable membrane devices (SPMDs) were deployed and sediments were collected from five sites in the Detroit River and from one site in western Lake Erie. Sample extracts were analyzed for concentrations of PAHs, PCBs, and selected organochlorine insecticides (DDT compounds, chlordane compounds, and HCH isomers). Both SPMD and sediment extracts were tested for lethality in an early life-stage mortality assay with Japanese medaka (Oryzias latipes). The mean concentrations of PCBs, PAHs, and DDT compounds in sediments and SPMDs were highest at three sites in industrialized regions of the Detroit River; at Zug Island near the outflow of the Rouge River, at Elizabeth Park in the Trenton Channel, and at Celeron Island downstream of the Trenton Channel. The mean concentrations of contaminants in sediments and in SPMDs from the various sites were highly correlated, indicating that contaminants in the Detroit River are partitioning between sediments and the dissolved phase of the water column. The lethal concentrations (LC50s) of extracts to early life stages of medaka were highly correlated with the concentrations of PAHs in the samples. This study illustrates the value of using SPMDs as devices for monitoring aquatic contamination, and the ease with which in vivo toxicity tests can be used to screen SPMD extracts prior to analytical studies.

Aromatic Hydrocarbons in Biota from the Detroit River and Western Lake Erie

Polynuclear aromatic hydrocarbons (PAHs) and PCBs in zebra mussels were elevated to concentrations greater than 5,000 ng/g lipid and 15,000 ng/g lipid, respectively, at the Ambassador Bridge in the Detroit River and concentrations gradually declined at downstream locations, which included three stations in the western basin of Lake Erie (Middle Sister Island, East Sister Island, Pelee Island). PCB concentrations in zebra mussels collected at the stations in western Lake Erie were elevated relative to the concentrations in mussels at the upstream end of the Detroit River (Stoney Point). There is no evidence that PAH contamination in the Detroit River elevated PAH concentrations in zebra mussels in western Lake Erie relative to mussels at Stoney Point. Fluorescent aromatic compounds (FACs) representing metabolites of PAHs were analyzed in the bile of gizzard shad (Dorosoma cepedianum) and freshwater drum (Aplodinotus grunniens) collected from several sites in the Detroit River and western Lake Erie. Mean FAC concentrations were >l,000 ng BaP equivalents per mL of bile in fish from the Trenton Channel and Boblo Island in the Detroit River, but FAC data provided no evidence that fish captured at two sites in western Lake Erie (East Sister Island, Pelee Island) were exposed to elevated concentrations of PAHs through ingestion of contaminated biota or exposure to contaminated sediments.

The Prevalence and Histological Appearance of Lip Papillomas in White Suckers (Catostomus commersoni) from Two Sites in Central Ontario, Canada

The white sucker, Catostomus commersoni (Lacapede), has been proposed as a sentinel species to monitor environmental health in the Great Lakes. In a population of white suckers spawning in the Ganaraska River, Lake Ontario (Port Hope, Ontario) there was an elevated prevalence of lip papillomas (46%), body papillomas (1.4%), and mucoid plaques (47%) compared to an inland reference population from the Squaw River, Little Bald Lake, Ontario (5%, 0%, and 0.5%, respectively). Multiple lip papillomas, and papillomas in apposition were prevalent in Ganaraska River suckers (17%) but rare in Squaw River suckers (1.2%). The prevalence of lip papillomas was not related to age or size, but papillomas at the Ganaraska site were up to 10 times larger than papillomas at the Squaw site. Relative papilloma prevalences at the two sites were correlated with relative concentrations of persistent contaminants (PCBs and OC compounds) in fish tissue. Histologically, lip and body papillomas were classified as benign hyperplasia and could be differentiated from normal tissue and mucoid plaques on the basis of biochemical (Protein Kinase C) activity. In laboratory experiments, mucoid plaques disappeared completely within 96 hours of antibiotic treatments (100% of treated suckers vs. 15% of untreated controls) and re-infection was not observed. These experiments indicate that mucoid plaques are not true neoplasms.