2.3 Exploratory Analysis of the Potential Health Impacts of Climatic Variability and Air Pollution

One of the most readily apparent contemporary factors linking climate to human health is air pollution. Important progress has been made in reducing U.S. air pollution since the first Clean Air Act was passed in 1970, but summer haze and its constituent particulate matter and photochemical air pollutants remain substantial ongoing problems across the U.S. Short-term meteorological effects on air pollution are readily observable but variably predictable. Furthermore, our understanding of longer-term climatological relationships to air pollution remains incompletely defined. Exposures to air pollutants have serious public health consequences. Ground-level ozone (O3) can exacerbate respiratory diseases, especially asthma, by damaging lung tissue, reducing lung function, and sensitizing the lungs to other irritants (Romieu, 1999). More recent epidemiologic studies have found significant associations of ambient O3 levels with respiratory hospitalizations and premature death (U.S. EPA, 2006). Epidemiologic studies have also found that exposure to particulate matter can aggravate existing respiratory and cardiovascular diseases, alter the body’s defense systems against foreign materials, damage lung tissue, and may cause cancer and premature death (Lambert et al., 1998; U.S. EPA, 2004). Health effects of exposures to carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen dioxide (NO2) can include visual impairment, reduced work capacity, aggravation of existing cardiovascular diseases, effects on breathing, respiratory illnesses, lung irritation, and alterations in the lung’s defense systems (Lambert et al., 1998). Climate change may affect ambient air pollutants by (1) influencing weather and thereby local and regional pollution concentrations (Penner et al., 1989); (2) altering anthropogenic emissions,