Climate Change and Health Series - Air Quality and Public Health
Climate change impacts, including higher temperatures, longer/more extreme wildfire seasons and increasing ground-level ozone may worsen air quality. Poor air quality is associated with several health effects including diminished lung function, asthma attacks, coughing and long-term exposure can increase risk of lung cancer, cardiovascular disease and developmental issues in children. Poor air quality contributes to more than 4 million deaths per year worldwide.
Ground-level Ozone
Ground-level ozone is created when pollutants emitted by vehicles, refineries, power plants and other sources react in heat and sunlight. Higher temperatures and increasing stagnant air conditions associated with climate change are generally projected to worsen ground-level ozone concentration. Ozone is a primary component of smog and associated with chest pain, coughing, throat irritation, reduced lung function and worsened emphysema and asthma. The U.S. Climate and Health Assessment projects tens to thousands of excess deaths attributable to climate-driven increases in ozone by 2030, unless off-set by significant decreases in overall pollutant emissions.
Wildfires and Particulate Matter (PM) 2.5
Particulate matter 2.5 refers to particles of dust, dirt, soot and chemical pollutants which are small enough to be inhaled and can lead to severe health impacts. These include cardiovascular disease, asthma, chronic obstructive pulmonary disease (COPD). Wildfires are a major annual source of PM2.5 in the United States, have grown more frequent and intense and are projected to worsen in the future due to climate change. Record breaking wildfires in recent years have contributed to hazardous air quality in the western United States. For example, in late summer 2020, smoke from fires in Oregon, California and Washington State caused the Pacific Northwest to experience the worst air quality in the world for several days. A health impact assessment conducted by researchers at the University of Washington found increased PM2.5 concentration during the 2020 poor air quality event was associated with increased all-cause mortality, cardiovascular disease and respiratory disease deaths.
Allergens
Outdoor allergies effect more than 25 million people in the United States and are one of the most common health issues for children. The production and distribution of airborne allergens such as pollen and mold spores may be influenced by climate change. For example, rising temperatures and delayed frost in the Midwest has contributed to lengthening of the ragweed pollen season.
Vulnerable groups
The elderly, children, immunocompromised and those with preexisting conditions are most at-risk from poor air quality. There also is a connection between socioeconomic status, air quality and associated disease risk in the United States. Low-income communities are more likely to live in neighborhoods with high concentrations(s) of ozone, PM2.5 and other pollutants relative to other areas. This disparity is reflected in prevalence of respiratory diseases such as asthma, rates are 11% higher among those with a family income below the Federal Poverty Level compared with those above.
Oversight
The Clean Air Act (1970) granted authority for air quality monitoring and regulation to the Environmental Protection Agency. State, local and tribal air agencies also complete these functions but are not permitted to establish weaker standards than those established by EPA. Addressing climate change has been restored as an EPA priority after removal during the trump Administration. This includes development of tools to identify those communities most at-risk from climate change impacts such as increased PM2.5 and ozone concentration.