Public Health Improvements Key to Adapting to Climate Change Risks

Continued improvements in public health and the vigilant monitoring both of climate conditions and of the nation's health status are key to protecting the health of Americans, according to the executive summary of the Report of the Health Sector, conducted as part of the U.S. National Assessment of the Potential Consequences of Climate Variability and Change. Led by researchers from the Johns Hopkins University School of Public Health and the Centers for Disease Control and Prevention (CDC), a team of scientists examined known connections between climate, weather patterns and human health risks. The health assessment found that if the global climate becomes warmer, some adverse health outcomes might result. However, the researchers also concluded that a variety of public health and other infrastructure controls can offset some of the risk. The executive summary of the report is published in the April issue of Environmental Health Perspectives, the journal of the National Institute of Environmental Health Science.

This health assessment was sponsored by and conducted in partnership with the Global Change Research Program of the U.S. Environmental Protection Agency as part of a multi-agency, congressionally mandated study of climate change in the U.S. The study calls for increased protection against flooding, drinking water contamination, heat waves and other weather-related events in the U.S.

"This report puts the best science forward to begin to identify the health risks from global climate change," said assessment co-chair Jonathan A. Patz, MD, MPH. "Our findings suggest some cause for concern, but if we continue as a nation to make public health a priority, adaptation may be feasible, although the financial costs of adapting are unknown."

"This report is unique because it is the first time a group of leading public health experts has been brought together to begin to assess potential health consequences of global climate change specific to the United States," adds Michael A. McGeehin, PhD, MSPH, of the Centers for Disease Control and Prevention and assessment co-chair.

The report examines certain health outcomes that may be affected by climate change, including those associated with temperature and precipitation extremes, air pollution, and diseases carried by contaminated water and food, and by insects, ticks and rodents. Researchers identified some groups within the U.S. at higher risk to certain environmental exposures. For example, the poor urban elderly face the greatest loss of life during summer heat waves because they often lack air conditioning. People with weakened immune systems are more in danger of getting sick if they drink contaminated water.

Heat waves present a set of identifiable risks, especially in urban areas. For example, Chicago, Philadelphia and Cincinnati have recently experienced heat waves resulting in increased numbers of illnesses and deaths. Climate scientists project that the severity and frequency of heat waves in the U.S. may increase in the future.

Increased rainfall and a water filtration system malfunction were cited in the report as part of the cause of a 1993 outbreak caused by Cryptosporidium, a microbiologic contaminant, in Milwaukee, Wisconsin. More than 400,000 illnesses were reported, including 54 deaths, because of the contaminated drinking water. The report also noted several other large outbreaks of food and waterborne illnesses from E. coli and Giardia. With respect to infectious diseases, the report recognizes that international travel makes climate impacts beyond our borders relevant for the U.S.

The report calls for measures that would increase the resilience of public health to changes in climate and would improve public health regardless of climate change. These measures include building codes and zoning ordinances to prevent storm damage, advanced weather warning systems, improving disease surveillance and prevention programs, enhanced sanitation systems, health education, public drinking water safeguards and continued air pollution controls.