Friday, June 27, 2014

EPA Science Advisers: Current Smog Standard Way Too Weak -- In Fact, Even the Top of Our Recommended Range May Be Illegally Weak!

EPA's Science Advisers have finally weighed in officially with a recommendation on what the EPA should do to change national health standards for ozone, commonly referred to as smog.  And their letter is a doozy: the scientists not only note that the current standard of 75 parts per billion is too weak -- but that the top part of their own recommended range (60 to 70) may be illegally weak as well!

This recommendation could pose a real dilemma for EPA, whose management has seemed skittish about this key public health issue since a Running-for-Reelection President Obama and his White House henchmen killed an effort in 2011 to set a tougher standard of 70.  (Don't believe me about the skittish remark?  Do a search and find out how often EPA politicos have talked about ozone since 2011.) 

It's going to be tough for EPA to sweep this issue under the rug in light of the scientists' letter.

Based partly on more recent scientific evidence, the scientists assert that even a standard of 70 would mean "adverse" health effects "including decrease in lung function, increase in respiratory symptoms, and increase in airway inflammation" and that "it may not meet the statutory requirement to protect public health with an adequate margin of safety." EPA's staff health risk assessment on this issue noted earlier that smog causes death and disease -- and that the tougher the standard, the lower the expected death rate.

The "policy advice" of the science advisers: set a standard tougher than 70.

A reluctant EPA is under a court order to propose a decision on this issue by December of this year and to make a final decision by October 2015.   

The full letter is here:

Read on for a few highlights from the letter:

…The CASAC further concludes that there is adequate scientific evidence to recommend a range of levels for a revised primary ozone standard from 70 ppb to 60 ppb. The CASAC reached this conclusion based on the scientific evidence from clinical studies, epidemiologic studies, and animal toxicology studies, as summarized in the Integrated Science Assessment (ISA), the findings from the exposure and risk assessments as summarized in the HREA, and the interpretation of the implications of these sources of information as given in the Second Draft PA. However, as noted below, we believe there is an important distinction in our finding and advice regarding the upper bound level of 70 ppb as compared to that of EPA staff as given in the Second Draft PA

In reaching its scientific judgment regarding a recommended range of levels for a revised ozone primary standard, the CASAC focused on the scientific evidence that identifies the type and extent of adverse effects on public health. The CASAC acknowledges that the choice of a level within the range recommended based on scientific evidence is a policy judgment under the statutory mandate of the Clean Air Act. The CASAC advises that, based on the scientific evidence, a level of 70 ppb provides little margin of safety for the protection of public health, particularly for sensitive subpopulations. In this regard, our advice differs from that offered by EPA staff in the Second Draft PA. At 70 ppb, there is substantial scientific evidence of adverse effects as detailed in the charge question responses, including decrease in lung function, increase in respiratory symptoms, and increase in airway inflammation. Although a level of 70 ppb is more protective of public health than the current standard, it may not meet the statutory requirement to protect public health with an adequate margin of safety. In this regard, the CASAC deliberated at length regarding advice on other levels that might be considered to be protective of public health with an adequate margin of safety. For example, the recommended lower bound of 60 ppb would certainly offer more public health protection than levels of 70 ppb or 65 ppb and would provide an adequate margin of safety. Thus, our policy advice is to set the level of the standard lower than 70 ppb within a range down to 60 ppb, taking into account your judgment regarding the desired margin of safety to protect public health, and taking into account that lower levels will provide incrementally greater margins of safety. 
Here is the EPA health risk assessment I referenced earlier:

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