|Impaired immunity in harbour seals (Phoca vitulina) exposed to bioaccumulated environmental contaminants: review of a long-term feeding study|
de Swart, R.L.; Ross, P.S.; Vos, J.G.; Osterhaus, A.D.M.E. (1996). Impaired immunity in harbour seals (Phoca vitulina) exposed to bioaccumulated environmental contaminants: review of a long-term feeding study. Environ. Health Perspect. 104(Suppl. 4): 823-828
In: Environmental Health Perspectives. National Institute of Environmental Health Sciences: Research Triangle Park, N.C.. ISSN 0091-6765, more
|Also published as |
- de Swart, R.L.; Ross, P.S.; Vos, J.G.; Osterhaus, A.D.M.E. (1995). Impaired immunity in harbour seals (Phoca vitulina) exposed to bioaccumulated environmental contaminants: review of a long-term feeding study, in: de Swart, R.L. Impaired immunity in seals exposed to bioaccumulated environmental contaminants = Immuunsuppressie in zeehonden blootgesteld aan in de voedselketen geaccumuleerde milieuvervuilende stoffen. pp. 113-119, more
Bioaccumulation; Disease resistance; Immunity; Marine environment; Marine mammals; Mortality; Mortality causes; Pollution effects; Reviews; Reviews; Reviews; Phoca vitulina Linnaeus, 1758 [WoRMS]; ANE, Baltic [Marine Regions]; Marine
|Authors|| || Top |
- de Swart, R.L.
- Ross, P.S.
- Vos, J.G.
- Osterhaus, A.D.M.E.
Mass mortalities among seals and dolphins inhabiting contaminated marine regions have led to speculation about a possible involvement of immunosuppression associated with environmental pollution. To evaluate whether contaminants at ambient environmental levels can affect immune function of seals, we carried out an immunotoxicological study under semifield conditions. Two groups of 11 harbour seals (Phoca vitulina) originating from a relatively uncontaminated area were fed herring from either the highly polluted Baltic Sea or the relatively uncontaminated Atlantic Ocean. Changes in immune function were monitored over a 2 1/2-year period. The seals that were fed contaminated Baltic herring developed significantly higher body burdens of potentially immunotoxic organochlorines and displayed impaired immune responses as demonstrated by suppression of natural killer cell activity and specific T-cell responses. During a 2-week fasting experiment performed at the end of the feeding study, mobilization of organochlorines from the blubber did not lead to a strong increase of contaminant levels in the blood, and no enhancement of the existing immunosuppression was observed. These results demonstrate that chronic exposure to environmental contaminants accumulated through the food chain affects immune function in harbour seals, whereas short-term fasting periods, which are normal for seals, do not seem to pose an additional risk. The seals of this study were not exposed perinatally to high levels of environmental chemicals, and body burdens of organochlorines measured near the end of the study were lower than those generally observed in free-ranging seals inhabiting many contaminated regions. Therefore, it may be expected that environmental contaminants adversely affect immune function of free-ranging seals inhabiting contaminated regions at least as seriously as observed in these studies.