Public Health Consequences of Climate Change
By Corydon Ireland
Heroes save lives. Consider Joel Schwartz, for example, a onetime MacArthur Fellow who is a professor of environmental epidemiology at the Harvard School of Public Health and an associate professor of medicine at Harvard Medical School. In his days with the U.S. Environmental Protection Agency (EPA), Schwartz researched and wrote the rule that in the 1980s banned lead in gasoline. He also did the research that resulted in restricting particulate matter in vehicle exhaust.
Those rules saved more than lives. An Office of Management and Budget study found that 80 percent of the economic benefits of all government regulations come from controlling lead and particles in fuels. “I’ve often thought,” Schwartz says wryly, “I should work on a commission basis.”
At Harvard since 1994, Schwartz still concentrates on the health effects of pollutants. He has also studied how micronutrient antioxidants affect respiratory health; improved ways to model environmental health effects; and has even looked into the ways water-borne diseases impact drinking water systems in First World countries. He and his research partners have focused particularly on the health effects of traffic pollution, linking it to high blood pressure, hardening of the arteries, and changes in the heart’s electrical activity. Along the way, Schwartz developed a model that estimates long-term exposure to pollution from traffic at any address in Massachusetts.
Schwartz and his colleagues are also studying the genes that mobilize the body’s defenses against oxidative stress caused by pollution. For example, they are examining how air pollutants affect methyl groups, which shut genes on and off during the manufacture of proteins that respond to infection.
The potential public health consequences of climate change are another important focus of research. “We’re going to have more extreme weather,” Schwartz says, so his team is studying the health consequences of very hot and cold days, heavy rainfall, and other expected climate change disruptions. That work requires terabytes of data, including all U.S. death certificates going back decades and all Medicaid hospital admissions data from 1985 onward.
By the time Schwartz arrived at Harvard in 1994, he had already published about 350 papers on health epidemiology—all the more remarkable since he never once took an epidemiology course. “But I teach courses,” he says. “That’s a good way to learn.”
Schwartz earned a doctorate in physics from Brandeis University in 1980. His specialty was theoretical condensed matter, a field that involved not only how things interact, but was also a lesson in “many-ness.” When a large number of things interact, he says, “you start seeing behaviors you wouldn’t have predicted.” The experience proved transferable to the field of epidemiology, which he taught himself by doing cost benefit analyses while at the EPA. That experience taught him to focus his attention on the problems that would save and improve the most lives, says Schwartz. “My philosophy is: Do some quick and dirty estimates of what the public health benefit might be, and then work on the ones where it might be big.”
This article originally appeared in the Fall/Winter 2011 issue of Environment@Harvard.