EPA’s Ozone Rule and the Scientization of Policy

Susan Dudley
by Susan E. Dudley, Director
October 07, 2015

The Environmental Protection Agency (EPA) struck a blow to communities across America with its new rule reducing the ground-level ozone standard to 70 parts per billion (ppb).  Many parts of the country still cannot meet the 75 ppb standard set in 2008 (or even the 80 ppb level set in 1997), and businesses and state leaders have been pleading with EPA not to tighten it further.  Concerns about the job- and growth-killing effects of ever-tighter standards, however, have fallen on deaf ears.

EPA claims its new standard is requisite to protect public health and that it is based purely on science, untainted by economic considerations.  That’s poppycock.

All parties to the debate have accused each other of using bad science or politicizing science, but as I show in a new paper, what they are really doing is “scientizing policy.”

Science is important, but rarely sufficient for making policy decisions for two reasons. First, while scientific information is essential for understanding questions of fact, it can’t make the ultimate policy decisions regarding what should be. Second, when predicting health risk, scientists will never have complete information, so bureaucrats must make assumptions and judgments when they interpret scientific information for rulemaking.

Yet the Clean Air Act does not recognize this.  It requires EPA to revisit the national ozone standard every five years and base the decision of whether to revise it on science alone. No other considerations, such as economic impact, can be taken into account.

When science is the only factor that can legally be considered in setting a standard, no one is immune to the temptation to put a spin on science to advance policy goals.

While some judgment is necessary to translate scientific evidence into policy, current procedures are not transparent, and lead to distortions and false precision in the presentation of scientific information. These practices blur the line between science and policy and contribute to the scientization of policy.

Policymakers and the public are often unaware of the influence of hidden policy choices or that alternative, equally plausible, assumptions yield very different estimates of risk. EPA presents its new ozone standard as if it were a magic number – exactly meeting the statutory requirement to be “requisite to protect public health” with an “adequate margin of safety,” but going no further.  It provides precise-sounding predictions of the health benefits to be achieved, but its pronouncements don’t admit to the considerable uncertainty about the actual risk, or EPA’s reliance on biased inferences and assumptions for handling that uncertainty.

For example, EPA claims its new standard will save 660 deaths, and thousands of cases of asthma and bronchitis.  However, Dr. Tony Cox, who analyzed EPA’s ozone data and risk assessment carefully, concludes that further reductions in ozone levels will make no difference to public health, and that “past reductions in ozone have had no detectable causal impact on improving public health.”

We can all agree that politicians should not politicize science by distorting what scientific studies conclude.  But we should also be wary when scientists and unelected officials attempt to exert influence on policy decisions by selectively presenting, or even distorting, scientific findings—the scientization of policy.

The Clean Air Act’s pretense that science alone can determine the ideal ozone standard virtually guarantees the scientization of policy.  Those involved in the regulatory decision have incentives to hide rather than reveal scientific uncertainty and to dismiss and denigrate dissenting views. Key policy choices, disguised as science, rest with technical staff, while policy makers charged with making hard policy decisions avoid responsibility by claiming their hands were tied by the science.

This has evolved into an adversarial process, characterized by harsh rhetoric in which each party claims the science supports its preferred policy outcome and questions opponents’ credibility and motives, rather than a constructive discussion regarding very real tradeoffs.  We won’t know the real reasons why EPA chose to revise the already-stringent standard or why it chose 70 ppb as opposed to 65 ppb (as some had hoped) or something in between. 

Communities across the nation that will have to sacrifice to implement the new standard deserve better.

Download the commentary.


A similar version of this commentary was printed in Reuters’, “The Great Debate” section, Why ‘science’ alone isn’t enough for setting environmental policy, by Susan E. Dudley, October 2, 2015.


See also: Regulatory Science and Policy: A Case Study of the National Ambient Air Quality Standards, Susan E. Dudley, September 9, 2015