Drowning in a Sea of Sufficient Ozone Research: An Open Letter to EPA Administrator Scott Pruitt

June 9, 2017 | 2:28 pm
Gretchen Goldman
Former Contributor

UPDATE, August 7, 217: On August 2, EPA Administrator Pruitt reversed his decision to delay the 2015 ozone standard by one year, following lawsuits filed by 15 states, the District of Columbia and several nonprofit groups. This move may be because Administrator Pruitt listened to legal advice, not necessarily scientific advice, but the end result will be science-based protections from ozone pollution for all Americans starting now. So we can all breathe a little easier.


Dear Administrator Pruitt,

When you decided this week to delay the 2015 ozone rule by one year, citing “insufficient information,” did you think about the science of ground-level ozone? Did you look at the data showing that ozone pollution is widespread across the country? And importantly, did you look at the detrimental health impacts that ozone pollution has for Americans?

As the law requires, the ozone standard must provide an adequate margin of safety for the most vulnerable populations—including the elderly, children, and those with lung diseases. I know that you are familiar with—actually hostile to—the ozone rule and its basis in the Clean Air Act. In fact, you’ve spent years fighting the (strong) legal and scientific basis for ozone protections and other environmental safeguards.

I’m sure you remember suing the EPA—alongside fossil fuel industry co-parties who gave to your political action committees—over the ozone rule, a challenge you have said was “based, in part, on concerns that EPA has not adequately assessed the available science.” You might even remember vowing, back when the rule was recently proposed, to “challenge the EPA’s misguided and unlawful overreach” in part because the “EPA has not yet articulated how the rule will further improve public health.”

So Administrator Pruitt, I have to ask; what are your definitions of “insufficient” and “adequate” and “articulation”? Because I have looked at the science, and I can tell you that we have more than sufficient information to act on it, contrary to what you claim.

As an air quality scientist, I’ve studied the data on ozone and health. I submitted my own opinion on the ozone rule during its official comment period. I can assure you we are standing on solid ground when it comes to the ozone rule. For your quick reference, here’s a rundown of just how incredibly sufficient the science is on the public health threat of ground-level ozone pollution.

1,251 pages of scientific assessment

As part of the update to the ozone standard, EPA conducts the Integrated Science Assessment (ISA). The 1,251-page document is produced by EPA scientists and surveys the current scientific literature on ozone (including one of my own papers). The peer-reviewed document finds several “causal” and “likely causal” relationships between ozone pollution and health effects. Of note, the report identifies “a very large amount of evidence spanning several decades [that] supports a relationship between exposure to O3 and a broad range of respiratory effects.” In addition, the report finds associations between ozone and short-term cardiovascular effects and total mortality, along with long-term respiratory effects.

Science advisers agree

As I’ve written before, the Clean Air Science Advisory Committee (CASAC), or the group of external independent subject-matter experts that EPA uses to provide scientific recommendations for the standard, came to the conclusion that the standard should be tightened. In its letter to the EPA administrator, the science advisors recommended a range of 60-70 ppb for the standard. In addition, the committee concluded that although 70 ppb was included in its recommended range, such a standard would not provide an “adequate margin of safety,” as the Clean Air Act mandates. The committee went on to note that with a 70-ppb standard there is “substantial scientific evidence of adverse effects … including decrease in lung function, increase in respiratory symptoms, and increase in airway inflammation.”

More scientists agree

The Ozone Review Panel was an additional set of external independent experts that works with CASAC to discuss the state of the science and review the ISA. These experts were brought in to provide additional expertise specific to ozone. This panel largely concurred with lowering the standard to something in the 60 to 70 ppb range as well, noting that a standard below 70 ppb would be more protective of public health.

None of this is new

It’s worth reiterating that the above voices recommending a lower standard are joining those from many years previous. In fact, CASAC first proposed that the ozone standard be in the 60 to 70 ppb range back in 2007. States have known—and have been preparing for a tighter ozone standard—for a very long time. Despite your suggestion otherwise, states have had ample opportunity to prepare for this standard that was finalized nearly two years ago.

The bottom line is that the law requires setting the ozone standard based on science and science alone. The administration must set a standard that is protective of public health with an adequate margin of safety and cannot legally consider economic arguments.

Do you feel up to this task, Administrator Pruitt? Are you able to do your job of protecting the public from ozone threats? And importantly, can you carry out the mission of the EPA of protecting the public health and environment? My colleague Andrew Rosenberg raised concerns before you were even appointed and this decision (among others) proves those concerns were well placed.

If you’d like more information, you can read more of my posts on the EPA update to the ozone standard herehere, and here. And I know many air quality scientists who would be happy to tell you more about what they know. I assure you, Administrator Pruitt, we are drowning in a sea of sufficient science on ozone, if only you’ll listen to the scientists.


Gretchen Goldman