Pet dogs as sentinels for environmental contamination

The presence of environmental contaminants in air, water and food may pose significant health risks to the exposed human population. However, problems associated with assessing chronic exposure to low doses of environmental c hemicals, multiple exposure routes, diseases with long latency periods, and non-specific health outcomes make it difficult to conduct the appropriate human epidemiologic studies. It may be useful to complement human epidemiol ogy with animal studies. Animals monitored or evaluated in situ for the app ropriate suite of endpoints can provide information about both exposure lev els and potential adverse health effects. Animals have served as sentinel i ndicators for health effects associated with a number of environmental expo sures, including pesticides and asbestos. Pet dogs may be particularly valu able sentinels because they share the human environment. In addition, dogs respond to many toxic insults in ways analogous to humans, they have physio logically compressed life spans, and they are free from some important life style risk factors for disease. An example of how pet dogs may be used as s entinels for potential human health hazards involves a study of the genotox ic effects resulting from exposure to a mixture of chemicals from nearby Su perfund sites. We conducted a cross-sectional study of exposed dogs (living in the community with the Superfund sites) and controls (living in a nearb y community). The pet owners completed a questionnaire, and we collected a blood sample from each dog. The blood samples were analyzed for standard cl inical parameters and assays for possible genotoxic effects (peripheral blo od lymphocyte micronucleus frequency and lymphocyte subtyping). Pet dogs li ving near the Superfund sites had a higher micronucleus frequency than cont rol animals, suggesting that the dogs may have been exposed to environmenta l contaminants from these sites. (C) 2001 Elsevier Science B,V, All rights reserved.