Asthma Rates Have Increased While Ozone Levels Have Fallen

By at 23 October, 2014, 8:40 pm

By Karen Kerrigan-

The Environmental Protection Agency (EPA) often invokes asthma as the reason to lower national ambient air quality standards for ozone. Ozone, EPA asserts, can worsen the condition for asthma sufferers, especially children. But as Texas state toxicologist Dr. Michael Honeycutt shows, asthma rates have been increasing, yet ozone levels have been declining. For these and other reasons Honeycutt says “there will be little to no public health benefit” if EPA lowers current ozone standards.CRS Logo

In the October edition of Natural Outlook, a monthly newsletter published by the Texas Commission on Environmental Quality, Honeycutt also notes something startling about EPA’s own analysis: It shows that lowering ozone concentrations in some cities would actually increase mortality. “Either this indicates that lowering the ozone standard defeats its stated purpose of protecting human health,” Honeycutt wrote, “or it indicates that something is wrong with the EPA’s interpretation of the data. Either way, it’s not a good argument for lowering the ozone standard.”

Of course EPA is not eager to have this information in the public domain, so, as Honeycutt points out, it is buried deep in EPA’s technical documents. “Further,” he wrote, “the EPA is not very forthcoming about the increased deaths. It’s not mentioned in the executive summary of their policy analysis, but it’s found on page 115 of Chapter 3, more than one third of the way through the 597-page document.”

Honeycutt also discovered that only “1 out of 12 studies considered by the EPA showed an association between long-term exposure to ozone and early death (after considering other pollutants).” As he noted, “This single study is used by the EPA as evidence that long-term exposure to ozone causes mortality.” And as he pointed out, “this study did not show higher mortality in Southern California, where some of the highest ozone levels in the country are measured.”

To get a comparative sense of the harm posed by ozone, Honeycutt compiled the chart below. “Many factors influence mortality,” he wrote, “and the effect of an increase in ozone by 10 ppb is tiny in comparison to these other influences.” As one can readily see, those in the lowest income bracket are far more likely to die from a 10 percent decrease in relative income than from a 10 parts per billion increase in ozone. By the same token, ozone total mortality doesn’t come close to the “total mortality in people who nap more than 1 hour per day.”


If that doesn’t demolish the case for lowering current ozone standards, the charts below provide a powerful illustration of Honeycutt’s points about asthma and ozone. As you can see, 8-hour ozone concentrations in Dallas County went down, yet the incidence of asthma went up. Moreover, hospital admittances for asthma were highest in winter, when ozone concentrations “are normally lowest.”


Honeycutt sums up his case this way: “There should be no doubt that lowering the standard will result in health benefits, but that is not the case for this consideration of the ozone standard. How can the EPA in good conscience make a policy decision this expensive when the data are so contradictory that their own modeling predicts more deaths in some areas from lowering the standard?”

Good question. It’s time for EPA to re-evaluate the science of ozone and avoid lowering the standard, an action that, according to NERA Economic Consulting, could cost the economy $270 billion annually and destroy thousands of jobs. That’s bad for the economy, bad for small businesses, and bad for public health.

The Center for Regulatory Solutions is a project of SBE Council.


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