By Michael McGeehin and Jonathan Patz

The first stage of the health sector assessment is nearing completion.  The executive summary of the report of the Health Sector will be published in the April issue of Environmental Health Perspectives.  The assessment focuses on five key public health impact areas: (1) temperature-related illnesses and death; (2) health effects related to storms and precipitation extremes; (3) air pollution-related health effects; (4) water- and food-borne diseases; and (5) vector-and rodent-borne disease.  These areas are outlined below.

Temperature-related illnesses and death

The health sector assessment addressed what is known about the relationship between heat and morbidity and mortality in the United States, including how Americans are currently protected from the risk of heat-related mortality.  We also identified any groups of people that are particularly vulnerable to heat, such as the urban elderly, children/infants, illegal immigrants living or traveling along the southern border, and people with cardiorespiratory or other illnesses.  Possible adaptive measures were identified and discussed.   Finally, there is ongoing quantitative analysis of projections of heat mortality based on national assessment climate scenarios, and results should be available later in the year.

Health effects related to storms and precipitation extremes

Climate change could alter the frequency and severity of extreme weather events.  The assessment investigated such changes in the U.S., including flash floods, mudslides, and storm surges.  Baseline impacts of tornadoes and hurricanes were assessed, using various plausible assumptions about how these might change in the future. The assessment also considered what adaptation strategies are available and appropriate.

Air pollution-related health effects

Looking at toxicological studies, human clinical studies, and epidemiological/ecological studies, the assessment summarized what is known about the association between air pollution and adverse health effects.  The role of climate in the formation of secondary air pollution (e.g., ozone and fine particulate matter) was explored; the assessment also looked at the relationship between weather/climate and natural emissions of air pollutants and natural allergens.  As with other sections, the assessment looked at current activities to reduce health risks from exposure to air pollution, as well as legal and regulatory activities, air pollution alerts, and monitoring and research.  Finally, possible adaptive measures were identified and discussed.

Water- and food-borne diseases

The assessment evaluated the current trends in morbidity and mortality associated with drinking water in the United States, as well as the ways in which we currently protect ourselves from this risk (e.g., by chlorination).  The relationship between storm events and contamination of surface water, which could lead to the possible contamination of drinking water and foods, such as fruit crops irrigated with contaminated water, was explored.  People can also be exposed to contaminated freshwater sources as a result of flooding or similar events.  The assessment considered trends in water- and food-borne contamination, and in morbidity and mortality related to contaminated freshwater and marine water, under the given climate and socioeconomic scenarios.

Vector-and rodent-borne disease

Concerns have been raised that climate change could have an impact on the habitat of disease-carrying organisms such as mosquitoes and rats and on the pathogens they carry. Some diseases of concern include malaria, dengue fever, and encephalitis.  If climate change does increase the chance of exposure within the United States, the question remains whether people are adequately protected from disease because of vector control programs, housing conditions (e.g., the use of window screens and air conditioners), and other factors.  The assessment looked closely at what is known and not known about the relationship between climate and vector-borne diseases and trends in such diseases in the United States. Finally, there is ongoing quantitative analysis of projections of dengue fever based on NAST climate scenarios, and results should be available later in the year.

For more information, contact:

Jonathan Patz, Johns Hopkins University School of Hygiene and Public Health; 615 N Wolfe St., Baltimore, MD 21205; phone: (410) 955-4195; email: jpatz@jhsph.edu.