Air quality standards and your health
Current regulations for air quality do not adequately protect the health of the elderly and other vulnerable people. This is the conclusion of research and an accompanying editorial in the Journal of the American Medical Association (Dec. 28, 2017).
The Federal Clean Air Act of 1963 empowered the government to conduct research into monitoring and controlling air pollution. Subsequent amendments to the act established National Ambient Air Quality Standards (NAAQS). Review of the standards is required every five years.
The Environmental Protection Agency was established in 1970 to consolidate all research and regulations into the effects of pollution on human health.
The most recent update of NAAQS in 2012 set the upper limit of ground-level ozone at 70 parts per billion (PPB) during an eight-hour period. Concentrations above this level are deemed unhealthy. A 24-hour standard for fine particulate matter was set at 35 micrograms per cubic meter of air.
Ozone results from chemical reactions between nitrogen oxides and a variety of volatile, chemical compounds that are found in fuels, solvents and industrial chemicals. Hot, sunny weather promotes these reactions. Ozone damages cells lining bronchial passages. Sore throat and cough result. Lung function decreases with continuing exposure. Symptoms are more intense in people with asthma, emphysema and chronic bronchitis. Infants and children are especially sensitive to ozone’s toxic effects.
The ultra-fine particles known as fine particulate matter (PM2.5) are 2.5 microns or less in diameter (25,000 microns equal one inch). PM2.5 are released in vehicular exhausts, by burning of fuels in power and industrial plants, and from grass and woodland fires. Particles may form from chemical reactions between gases and droplets released by power plants. These reactions may occur many miles from the point of release. PM2.5 pass unimpeded into the air sacs of the lungs, where they corrode lining cells.
Short-term elevations of PM2.5 in the atmosphere are linked to increased hospital admissions for congestive heart failure.
Long-term exposure to PM2.5 has been linked to an increased risk of lung cancer.
Animal studies show that exposure of pregnant females to PM2.5 results in newborn with impaired lung function.
Unhealthy levels of ozone and PM2.5 often occur simultaneously.
The JAMA study analyzed from 2000 to 2012 daily levels of warm-weather ozone and PM2.5 for every ZIP code in the U.S. A second component of the study analyzed more than 22 million deaths in the Medicare population during this same interval. The combined data showed that short-term elevations of PM2.5 and ozone were clearly linked to increased risk of death in this population. Deaths increased in the days immediately following rises in ozone and PM2.5 levels. The risk was present at levels of ozone and PM2.5 that were within allowable limits set by NAAQS.
The study covered urban, suburban and rural areas of the continental U.S. The study further indicated that increasing age, female gender and dual Medicaid-Medicare eligibility were associated with higher mortality rates.
The accompanying editorial in JAMA reports that, in 2015, 107 million people lived in counties that did not meet standards for ground-level ozone. Twenty-three million resided in counties that did not meet PM2.5 standards.
Every proposal to tighten U.S. air-quality regulations has been met with fierce opposition from the fossil-fuel industry, manufacturing groups and proponents of limited government. Lawsuits may delay implementation of regulations for years. The Clean Power Plan, which was launched in 2015, is currently on hold as various legal challenges are processed.
Health, especially that of vulnerable populations, is not sufficiently factored into these debates. What value can be attached to the health of many thousands of children and the elderly, people with chronic lung disease or poor people? Who speaks for them in opposition to powerful advocates for relaxing air-quality standards?
The study in JAMA presents powerful support for tightening and enforcing air-quality standards.
Clif Cleaveland, M.D., is a retired internist and former president of the American College of Physicians. Contact him at ccleaveland@timesfreepress.com.