EPA's Endangerment Finding
Health Effects

The key effects that support EPA's determination that current and future concentrations of greenhouse
gases endanger public health include:

Temperature
    • There is evidence that the number of extremely hot days is already increasing. Severe heat waves
     are projected to intensify, which can increase heat-related mortality and sickness. Fewer deaths
     from exposure to extreme cold is a possible benefit of moderate temperature increases. Recent
     evidence suggests, however, that the net impact on mortality is more likely to be a danger because
     heat is already the leading cause of weather-related deaths in the United States.

Air Quality
    • Climate change is expected to worsen regional ground-level ozone pollution. Exposure to ground-
     level ozone has been linked to  respiratory health problems ranging from decreased lung function
     and aggravated asthma to increased emergency department visits, hospital admissions, and even
     premature death. The impact on particulate matter remains less certain.

Climate-Sensitive Diseases and Aeroallergens
    • Potential ranges of certain diseases affected by temperature and precipitation changes, including
     tick-borne diseases and food and water-borne pathogens, are expected to increase.
    • Climate change could impact the production, distribution, dispersion and allergenicity of
     aeroallergens and the growth and distribution of weeds, grasses, and trees that produce them. These
     changes in aeroallergens and subsequent human exposures could affect the prevalence and severity
     of allergy symptoms.

Vulnerable Populations and Environmental Justice
    • Certain parts of the population may be especially vulnerable to climate impacts, including the poor,
     the elderly, those already in poor health, the disabled, those living alone, and/or indigenous
     populations dependent on one or a few resources.
    • Environmental justice issues are clearly raised through examples such as warmer temperatures in
     urban areas having a more direct impact on those without air-conditioning.

Extreme Events
    • Storm impacts are likely to be more severe, especially along the Gulf and Atlantic coasts.  Heavy
     rainfall events are expected to increase, increasing the risk of flooding, greater runoff and erosion,
     and thus the potential for adverse water quality effects. These projected trends can increase the
     number of people at risk from suffering disease and injury due to floods, storms, droughts and fires.
The Technical Support Document, which provides extensive detail on this topic, may be found on our Web site at:
www.epa.gov/climatechange/endangerment.html.

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