Research Activities

Background: Animals as Sentinels of Human Environmental Health Hazards
Definition of Animal Sentinel
Challenges in the Use of Animal Sentinel Systems
The Yale Environmental Sentinel Studies Project
Project Goals
Current Initiatives
Project Director

Background: Animals as Sentinels of Human Environmental Health Hazards: The ãCanary in the Coal Mineä

-As human civilization exerts an ever-increasing impact on the global environment, there is an urgent need to quickly identify and understand hazards to human health due to environmental change. If wildlife and other animal populations could serve as an effective ãearly warning systemä for environmental health threats to humans, it could have a profound influence on public health practice and environmental health policy.

-At the end of the 19th century, coal miners in England and the US brought canaries into coal mines as an ãearly warning signalä for carbon monoxide and other poisonous gases. The birds, being more sensitive, would become sick before the miners, giving them a chance to escape or put on protective respirators.

-In recent years, a growing number of reports of adverse health effects in animal populations have prompted concerns about risks to human health from environmental contaminants. Examples include developmental abnormalities and population declines in amphibians, reproductive anomalies in fish, whales and reptiles, and behavioral disturbances in nesting bird populations.  It is inevitable that in the future, more observation of disease and population changes in wildlife populations will occur. How should the scientific community as well as local communities respond to such events? Are the wildlife populations actually signaling that something is happening in the environment which could pose a direct hazard to people as well? How can such linkages between ecosystem events and human health be made in a scientifically valid and useful manner?

Definition of Animal Sentinel:

Whereas indicators and monitors are species used to assess ecosystem effects of contamination, sentinels refer directly to human health and are defined as ãorganisms in which changes in known characteristics can be measured to assess the extent of environmental contamination and its implication for human health and to provide early warning of those implications.ä (OâBrien 1993)

Challenges in the Use of Animal Sentinel Systems:

-Among the human health scientific community, there has been uncertainty regarding the importance and relevance of diseases reported in wildlife, due in part to an unfamiliarity with the study methods used by wildlife health researchers. There is a major communication need to improve communication between the two scientific communities.

-One of the recommendations of recent Federal policy initiatives is that strategies be developed for the more effective use of wild animal populations as sentinels of potential environmental health threats. For example, what are the confirmatory studies which should be done in both animals and humans to follow-up the reports of a sentinel event?

-Can wildlife and domestic animals serve as effective ãsentinelsä- as part of an early warning system for chemical and biological warfare threats?

-Finally, when a cluster of human cases of disease is suspected to be due to an environmental exposure, concomitant studies in animal populations may be worthwhile.

The Yale Environmental Sentinel Studies Project:

The Environmental Sentinel Studies Project aims to address the need to foster interdisciplinary collaboration on such issues. It plans to bring together highly experienced scientists from Yale and people working in the field in organizations such as the National Wildlife Health Center, and the Consortium for Conservation Medicine. It plans to help participate in the training of both scientific and lay persons in how to carry out surveillance for adverse wildlife events of relevance to human health.

Project Goals:

The goals of the project include:
1. To promote collaborative responses to reports of sentinel events in the environment by human and animal scientists..
2. To foster communication between human environmental health researchers and wildlife health professionals.

Current Initiatives:

1. Creation of an advisory board of experts from the fields of environmental health, wildlife biology, toxicology, infectious diseases, epidemiology and public health, ecology, and veterinary medicine.
2. Development of a ãcommon languageä for human and animal health scientists studying and discussing wildlife sentinel events.
3. Creation and maintenance of a comprehensive database of published studies using animal populations as sentinels of human health hazards.
4. Creation of a website containing the above database as well as guidelines and resource information on how to carry out studies of animal sentinel events.
5. Creation of a resource databank of professionals and community experts with experience in the investigation of wildlife health events.
6. Creation of methods for linking wildlife health events with possible human health threats to adjacent communities, using GIS mapping and other innovative techniques.
7. Development of protocols for a ãrapid response teamä of epidemiologists and biologists to respond to identified outbreaks of disease in wildlife populations which are possibly related to environmental hazards.

Project Director:

Peter Rabinowitz, MD, MPH, ( peter.rabinowitz@yale.edu ) is an assistant professor of Occupational and Environmental Medicine at the Yale University School of Medicine. He has been actively interested in the implications of animals as sentinels of human environmental health hazards for several years, as well as the need to develop a common language between animal health and human health fields. He has recently published a review of wildlife sentinel studies  ( Journal of Environmental Medicine Vol 1 Issue 4 1999, pages 217-229 Published online 28 Feb 2001 Online ISSN: 1099-1301 Print ISSN: 1095-1539)