Is Summertime Smog an Increasing Threat to Public Health?

There’s no need to sweat summertime smog. Despite the hype, air quality is better now than it has been in decades.

By now, most Americans are acquainted with code red days, ozone action days, ozone awareness days, and other smog alerts. These alerts are issued by local governments during the hottest summer days to alert the public to health hazards posed by the build-up of ground-level ozone and to encourage the public to reduce activities, such as driving and lawn mowing, which contribute to the problem.

Hot days create ideal conditions for the creation of ground-level ozone, which is formed through a chemical reaction between volatile organic compounds (VOCs) and nitrogen oxide (NOx). Intense sun and heat accelerate the reaction between VOCs and NOx, increasing ground-level ozone. Stagnant air, which tends to accompany summertime heat, makes the problem even worse by slowing the dispersion of the ozone.

Government officials warn that the build-up of an excessive amount of ozone poses a health risk by increasing the chance that children, the elderly and those with respiratory problems may experience coughing, wheezing, eye irritation, nausea and shortness of breath. While most medical experts agree that ozone in sufficient concentrations poses a health risk, there is wide disagreement on how high these concentrations must be to pose a serious health problem.

Given the rise in media coverage of smog alerts in recent summers, one is left with the distinct impression that the quality of the air we breathe is deteriorating. But air quality has actually improved steadily since 1970.

According to a new report by the Foundation for Clean Air Progress, levels of ozone and other major pollutants have fallen by a dramatic 34% since 1970. The report, Progress in Reducing National Air Pollutant Emissions: 1970-2015, is based on statistics from the Environmental Protection Agency. That report shows marked improvement in air quality across the board since 1970: Carbon monoxide emissions have fallen by 33%; nitrogen oxide emissions have dropped by 12%; volatile organic compounds have decreased by 42%; sulfur dioxide emissions have declined by 38%; particulate matter emissions have fallen by a whopping 75%; and lead emissions have dropped by 98%.

These improvements occurred despite robust economic growth and despite the fact that both automobile use and fuel consumption increased significantly.

America’s most heavily-populated urban areas have shown some of the most impressive gains: Between 1993 and 1997, Los Angeles exceeded federal standards for ozone 41% fewer times than it did between 1988 and 1992. The record of other major cities is similarly impressive: Chicago’s “ozone exceedance days” decreased by 45%, Detroit’s dropped by 47%, San Diego’s declined by 59% and Buffalo’s decreased by 75%.

And there is more good news. If current trends hold, pollution levels will continue to drop well into the 21st Century. According to EPA and U.S. Department of Energy statistics, an additional 32 million tons of emissions per year will be eliminated by 2015 (a further 22% reduction) – without any new regulations.

With all this good news, one wonders why the EPA continues to press for more stringent air quality regulations now. The U.S. Court of Appeals for the District of Columbia Circuit rejected more stringent standards proposed by the EPA earlier this year, saying that the agency had inadequately made the case for them on public health grounds.

Some advice to the EPA: Save taxpayers the litigation costs, the higher regulatory and consumer costs, and job losses by dropping the tougher standards. We’re doing just fine without them.


David Ridenour is vice president of The National Center for Public Policy Research. Comments may be sent to [email protected].

The National Center for Public Policy Research is a communications and research foundation supportive of a strong national defense and dedicated to providing free market solutions to today’s public policy problems. We believe that the principles of a free market, individual liberty and personal responsibility provide the greatest hope for meeting the challenges facing America in the 21st century.