UC-Davic veterinarians strengthen link between air pollution and cardiovascular disease

Davis, Calif. — The link between air pollution and onset of strokes/heart attacks is stronger because of a study conducted by two veterinary professors at the University of California-Davis (UC-Davis) School of Veterinary Medicine.

While the work was conducted to assess air pollution as it relates to public health, the ill health effects from air pollution apply to companion animals too.

The research, done by Dr. Dennis Wilson, a professor in the Department of Pathology, Microbiology and Immunology, and Dr. Fern Tablin, a professor in the Department of Anatomy, Physiology and Cell Biology, was part of a five-year Star grant UC-Davis received from the U.S. Environmental Protection Agency (EPA) to investigate the connection between fine particulate pollution and public health impacts in California.

"Veterinarians have always held an interest in basic science affecting people, as well as animals, says Lynn Narlesky, a spokesperson at UC-Davis School of Veterinary Medicine. "Their training with animals often allows them to contribute to research where animals are the best model for controlled studies. Our experts in comparative medicine and biomedical science are part of the One Health approach to society's most complicated challenges, with vets, physicians and other scientists involved."

According to the California Air Resources Board, which is part of the California Environmental Protection Agency, the particulate matter in air pollution is described as a complex blend of substances ranging from dry solid fragments, solid-core fragments with liquid coatings and small droplets of water. The particles vary in shape, size and chemical composition and can contain metals, soot, nitrates, sulfates and very fine dust. One source of particulate matter, including PM2.5 or fine-particulate matter, is exhaust from vehicles, especially diesel engines.

"Two major disease syndromes in humans are associated with episodes of high particulate matter (PM) exposure—asthma and death from cardiovascular disease," Wilson says. "The EPA grant studied the mechanisms of both these diseases, but our portion concentrated on trying to understand the connection between inhalation of PM and systemic inflammation that might lead to a heart attack."

By examining the platelets of mice exposed to PM2.5 from the San Joaquin Valley Air Basin, they found platelet activation in both winter and summer, which could promote clotting. Clots in the blood stream are a common cause of heart attacks and strokes.

Tablin adds that while huge smog inversions, like the one that killed close to 12,000 people in London in 1952 are rare; air pollution can affect people and animals within two days of exposure.

"While the impetus for these studies was the effects of air pollution on human health, the involvement of rural areas in this study does address issues in veterinary medicine," Wilson says. "For example, other researchers on campus are investigating the role of particulates as occupational risks for workers in high-density animal agriculture facilities. Our work suggests new ways to investigate these risks by evaluating platelet function in exposed workers."

The research is ongoing, Tablin says. In fact, the team is almost finished with two more papers. "It has been a joy to collaborate with some great people in the lab," she says, adding that the tests were conducted in UC-Davis labs with help from graduate and post-doctoral students, and from colleagues in the department of mechanical and aeronautical engineering.

Wilson and Tablin's study, published in February 2011, can be found at www.arb.ca.gov/research/single-project.php?row_id=64824.