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Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas).

A small isolated population of beluga whales (Delphinapterus leucas) that are highly contaminated by pollutants, mostly of industrial origin, resides in the St. Lawrence estuary, Québec, Canada. Overhunting in the first half of the century was the probable cause for this population to dwindle from s...

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Autores principales: De Guise, S, Martineau, D, Béland, P, Fournier, M
Formato: Texto
Lenguaje:English
Publicado: 1995
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1519273/
https://www.ncbi.nlm.nih.gov/pubmed/7556028
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author De Guise, S
Martineau, D
Béland, P
Fournier, M
author_facet De Guise, S
Martineau, D
Béland, P
Fournier, M
author_sort De Guise, S
collection PubMed
description A small isolated population of beluga whales (Delphinapterus leucas) that are highly contaminated by pollutants, mostly of industrial origin, resides in the St. Lawrence estuary, Québec, Canada. Overhunting in the first half of the century was the probable cause for this population to dwindle from several thousand animals to the current estimate of 500. The failure of the population to recover might be due to contamination by organochlorine compounds, which are known to lead to reproductive failure and immunosuppression in domestic and laboratory animals and seals. Functional and morphological changes have been demonstrated in thyroid gland and adrenal cortex in many species exposed to organochlorinated compounds, including seals. Morphological lesions, although different, were also found in belugas. Functional evaluation of thyroid and adrenal glands of contaminated (St. Lawrence) versus much less contaminated (Arctic) belugas is currently under way. Necropsy of St. Lawrence belugas showed numerous severe and disseminated infections with rather mildly pathogenic bacteria, which suggests immunosuppression. Organochlorine compounds and other contaminants found in beluga whales cause immunosuppression in a variety of animal species including seals. Thirty-seven percent of all the tumors reported in cetaceans were observed in St. Lawrence beluga whales. This could be explained by two different mechanisms: high exposure to environmental carcinogens and suppression of immunosurveillance against tumors. Overall, St. Lawrence belugas might well represent the risk associated with long-term exposure to pollutants present in their environment and might be a good model to predict health problems that could emerge in highly exposed human populations over time.
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spelling pubmed-15192732006-07-28 Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas). De Guise, S Martineau, D Béland, P Fournier, M Environ Health Perspect Research Article A small isolated population of beluga whales (Delphinapterus leucas) that are highly contaminated by pollutants, mostly of industrial origin, resides in the St. Lawrence estuary, Québec, Canada. Overhunting in the first half of the century was the probable cause for this population to dwindle from several thousand animals to the current estimate of 500. The failure of the population to recover might be due to contamination by organochlorine compounds, which are known to lead to reproductive failure and immunosuppression in domestic and laboratory animals and seals. Functional and morphological changes have been demonstrated in thyroid gland and adrenal cortex in many species exposed to organochlorinated compounds, including seals. Morphological lesions, although different, were also found in belugas. Functional evaluation of thyroid and adrenal glands of contaminated (St. Lawrence) versus much less contaminated (Arctic) belugas is currently under way. Necropsy of St. Lawrence belugas showed numerous severe and disseminated infections with rather mildly pathogenic bacteria, which suggests immunosuppression. Organochlorine compounds and other contaminants found in beluga whales cause immunosuppression in a variety of animal species including seals. Thirty-seven percent of all the tumors reported in cetaceans were observed in St. Lawrence beluga whales. This could be explained by two different mechanisms: high exposure to environmental carcinogens and suppression of immunosurveillance against tumors. Overall, St. Lawrence belugas might well represent the risk associated with long-term exposure to pollutants present in their environment and might be a good model to predict health problems that could emerge in highly exposed human populations over time. 1995-05 /pmc/articles/PMC1519273/ /pubmed/7556028 Text en
spellingShingle Research Article
De Guise, S
Martineau, D
Béland, P
Fournier, M
Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas).
title Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas).
title_full Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas).
title_fullStr Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas).
title_full_unstemmed Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas).
title_short Possible mechanisms of action of environmental contaminants on St. Lawrence beluga whales (Delphinapterus leucas).
title_sort possible mechanisms of action of environmental contaminants on st. lawrence beluga whales (delphinapterus leucas).
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1519273/
https://www.ncbi.nlm.nih.gov/pubmed/7556028
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