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Texas Commission on Environmental Quality (TCEQ) Written 

Comments to the Science Advisory Board (SAB) Ozone Review 

Panel for the March 23, 2011 Teleconference

Michael Honeycutt, Ph.D.

Division Director, Toxicology Division

Texas Commission on Environmental Quality

Austin TX, 78726

Telephone: 512-239-1795

E-mail: Michael.honeycutt@tceq.texas.gov

March 14, 2011

Holly Stallworth, Ph.D.

Economist and Designated Federal Officer

Clean Air Scientific Advisory Committee (CASAC)

Environmental Protection Agency, Mail Code 1400R

1300 Pennsylvania Ave., NW, Washington D.C. 20004

Phone: 202-564-2073

stallworth.holly@epa.gov

Dear Ozone Review Panel Members:

I, Dr. Michael Honeycutt, Director of the Toxicology Division of the Texas Commission 

on Environmental Quality, would like to offer the following written comments on behalf 

of the TCEQ. The Federal Register Notice for the March 23, 2011 Teleconference of the 

Clean Air Scientific Advisory Committee Ozone Review Panel indicated that members of 

the public could provide written comments. I have previously provided Oral comments to 

the panel on February 18, 2011. 

The current proposed standard is based primarily on ecological epidemiology studies. 

Ecological epidemiology studies are designed as hypothesis-generating studies and are 

not scientifically-rigorous enough to base such an important policy decision. Meta 

analyses of ecological epidemiology studies may give the appearance of hard data, but 

they have an extremely poor exposure component and studies conducted to date show 

only slight associations. Even a well-conducted epidemiology study is a blunt instrument

at best and not adequate to establish whether or not 75 ppb ozone is any less health 

protective than 65 ppb. When developing strategies to address ambient ozone, every ppb 
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reduction in the standard results in more emission reductions needed. If the standard is to 

be lowered, the scientific data must clearly demonstrate the health benefits that would 

result from the additional regulatory burdens. Speaking from the viewpoint of a state 

that has significant experience developing strategies to reduce ozone, we have plucked all 

of the low-hanging fruit. All that is left is severe pruning.

You yourselves have noted that personal exposure to ozone is not considered in 

developing this standard as illustrated in your letter dated June 5, 2006:

“The Ozone Staff Paper should consider the problem of exposure 

measurement error in ozone mortality time-series studies. It is known that 

personal exposure to ozone is not reflected adequately, and sometimes not 

at all, by ozone concentrations measured at central monitoring 

sites....Therefore, it seems unlikely that the observed associations between 

short-term ozone concentrations and daily mortality are due solely to 

ozone itself.” 

Also, many ecological studies have used patient medical records instead of patient 

histories to monitor exposure and assess health effects. Patient medical records are 

inadequate indices to associate ozone exposure and health effects.

EPA also used clinical studies published by Dr. William Adams as the basis for lowering 

the 0.08 ppm standard. EPA reanalyzed Dr. Adams’ data using t-tests rather than using a 

multiple comparisons post-hoc test, as pointed out by Dr. Adams himself in his 

comments to EPA. This reanalysis would not pass peer review. You should not give 

EPA a pass on it either.

Your job in this process is to ensure that EPA uses good science in deciding where to set 

the ozone standard. You are not policy makers. You don’t get to turn a blind eye to 

EPA’s inadequate science in the name of public health. You are supposed to hold EPA 

accountable to use scientifically-appropriate methodologies and analyses. You should 
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make EPA explain the uncertainty in the ozone standard to policy makers so that the 

policy makers, not you and EPA scientists, can make an informed decision that weighs all 

relevant factors. 

In conclusion, a policy decision this important must not be made just by using good 

science but also by understanding its limitations and uncertainties. The exposure 

estimates from the ecological epidemiology studies used to justify lowering the ozone 

standard do not account for personal exposure to ozone and are therefore faulty, as you 

yourselves have noted. It is scientifically-inappropriate to use ecological epidemiology 

studies to set the ozone standard. EPA should use appropriate statistical analyses in 

looking at the Adams clinical data.