Our environment is shared with our pets. They sleep in our beds, eat our food, and play on our lawns. They are also exposed to many environmental agents that can affect human health. And because companion animals acquire a similar spectrum of disease as people — on a much shorter time-scale — they can provide advance warning of human health risks.
National Academies of Sciences, Engineering, and Medicine workshop held Dec. 1-3The potential role of pets to monitor human-relevant environmental exposures that can influence aging or cancer was examined.
“We want to challenge the emerging field of exposure science because we all know that we are not dealing with just one chemical at a time or just one point in our lives,” said NIEHS Scientist Emeritus Linda Birnbaum, Ph.D., who chaired the workshop and the planning committee.
She explained to attendees that pet exposure data can provide valuable insights that complement traditional toxicological research such as cell-based studies or laboratory animal testing. The event attracted dozens upon dozens of experts and more than 500 people to join virtually.
Canary in the coal mine
The canary in a coal mine is a classic example of animals acting like sentinels to environmental hazards. Peter Rabinowitz M.D., University of Washington
He stated that canaries have three key characteristics that make them good sentinels. They are more susceptible to the hazard, more exposed to it, and have a shorter latency. This means that birds can become sick much faster than humans. Workers had enough time to put on respirators before canaries became ill from toxic gases or carbon monoxide in a mine.
Rabinowitz believes dogs can also be used as sentinels to detect cancer in humans. He said that canines are vulnerable to carcinogens and pointed out that the incidence of cancer is high in these animals. Dogs spend more time at their homes than people, at least during pre-pandemic years, and are more familiar with their surroundings. Their lifespan is shorter than that of humans.
“Studies of dogs as sentinels have untapped potential for detecting and better understanding environmental carcinogens, which can be difficult to study in humans,” said Rabinowitz.
He said that such research could aid scientists in detecting both new and established carcinogens as well as understanding patterns of exposure. This may help to improve human cancer prevention.
Companion animals, companion studies
Many types of cancer are now less common due to early detection and treatment. However, the incidence of certain cancers — such as skin, liver, kidney, and early-onset colorectal cancers — are increasing, according to Gary Ellison Ph.D.Acting director of the NIEHS Division of Extramural Research and Training. Ellison stated that he believes that environmental factors are contributing to this increase.
“However, the environment is incredibly complex, and there are several challenges in researching environmental exposures,” he said. Ellison pointed out that there is more work needed to address this complexity. It includes types and sources, spatial and time aspects of exposures and effects on biological pathways.
He described the National Cancer Institute, (NCI) Cohort ConsortiumThis resource, which includes seven millions of human study participants from 15 nations and four continents is intended to help scientists understand how the environment influences cancer. Ellison also discussed new cohorts — part of a collaboration between NCI and NIEHS — that will enable researchers to study how emerging and important environmental exposures may affect cancer risk.
Birnbaum was one of the participants. He suggested that companion animals could be a valuable part of long-term research. There are already prospective studies of dogs, such as the Golden Retriever Lifetime StudyThe Dog Aging Project.
(Marla Broadfoot, Ph.D. is a contract author for the NIEHS Office of Communications and Public Liaison.
Birnbaum claims that the One Health framework informed the workshop. It focuses on interconnectedness of animals and humans. (Photo courtesy Steve McCaw/NIEHS)