Response to Dr. Tony Cox’s Wall Street Journal opinion piece of 9/2/2015

Indra Frank, MD, MPHEnvironmental Health Project Director

Hoosier Environmental Council9/3/2015

Dr. Cox accurately points out that on average across the US asthma rates have continued to rise while air quality, including ozone levels, have improved (Cox, 2015). However, he does not take into account the distinction between the asthma rate and the incidence of asthma attacks. The asthma rate is what percent of the population has a diagnosis of asthma. The incidence of asthma attacks refers to the number of attacks among those who have a diagnosis of asthma. An asthma attack is an episode of constricted airways and difficult breathing that is disabling and can be severe enough to be life threatening. In the US there are approximately 500,000 hospitalizations for asthma each year (Silverman, 2010). A person who can control their asthma through reduced exposures to respiratory irritants and regular use of medications may have very few asthma attacks. If asthma in a population is well controlled, there is a lower incidence of asthma attacks.

Ozone increases the incidence of asthma attacks among those who already have a diagnosis of asthma. Ozone is a highly reactive molecule and it is through this reactivity that it is a potent irritant of the respiratory tract (McDonnell, 2012). By irritating and inflaming the respiratory tract, it triggers asthma attacks. Higher ozone levels have been shown to increase the number of asthma attacks and the number of emergency room visits (Ito, 2007) and hospital admissions for asthma (Silverman, 2010).

Ozone’s irritation of the respiratory tract means that ozone makes most lung diseases worse including bronchitis, emphysema, and pneumonia, as well as asthma. Ozone has been shown to increase emergency room visits for respiratory diseases (Tolbert, 2007), and higher ozone levels increase the risk of death due to respiratory causes (Jerrett, 2009). It has been estimated that reducing ambient ozone to 70 ppb could save up to 4,130 premature deaths each year in the US (Berman, 2012).

With the proposed revision of the ozone standard, the EPA is implementing the Clean Air Act as it was written by Congress. They are required by the Clean Air Act to review the ozone standard every five years and to set the standard to protect public health.

Dr. Cox expresses concern that EPA’s current proposal “undermines the credibility of regulatory science”; however, it could perhaps more accurately be argued that the current proposal will bring the ozone standard into better alignment with the science. The last time the standard was revised was in 2008. At that time EPA's Clean Air Science Advisory Committee unanimously recommended that the EPA set the ozone standard between 60 and 70 ppb based on their

review of 1700 studies on the health effects of ozone. Despite that strong recommendation, the EPA set the ozone standard at 75.

It has been seven years since the ozone standard was set at 75. So the EPA is behind on its congressionally mandated review, and there is now a court-ordered deadline for the next revision of the ozone standard. Since the last revision of the standard in 2008, there have been more than 1000 additional studies on ozone and health including studies showing harm at the current ozone standard of 75 parts per billion. Only a small subset of the scientific literature is cited in this reply. For a more comprehensive list of references see the EPA’s Health Risk and Exposure Assessment for Ozone published in August 2014.

Finally, Dr. Cox argues that the proposed ozone standard will hurt the economy, but evidence shows that cleaner air is better for the economy. The EPA estimates that lowering the ozone standard from 75 to 70 will produce $6.4 - $13 billion in health benefits but cost $3.9 billion to implement (EPA, 2014). Cutting ozone to 65 will produce even greater benefits. Long term trends have clearly shown that air quality regulations in the US have not hurt the economy. In fact, while overall air emissions have dropped 62% since 1980, the gross domestic product has gone up 145% (EPA, n.d.). On a micro level, communities have an abundant suite of off-the-shelf, cost-effective tools to reduce ozone levels, from ozone education programs to fostering more carpools to air emissions testing for older cars, to spurring more tree planting. These affordable, community-level programs improve overall quality of life, which strengthens, not weakens, a community’s economy.

References

Berman, J.D, et al. (2012). Env Health Perspect 120:1404-1410.

Cox, T. (2015, Sept 2). The EPA’s Next Big Economic Chokehold. The Wall Street Journal

EPA (2014, August) Health Risk and Exposure Assessment for Ozone. Available at http://nepis.epa.gov/Exe/ZyNET.exe/P100KBUF.txt?ZyActionD=ZyDocument&Client=EPA&Index=2011%20Thru%202015&Docs=&Query=&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&UseQField=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5CZYFILES%5CINDEX%20DATA%5C11THRU15%5CTXT%5C00000011%5CP100KBUF.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=p%7Cf&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1

EPA (2014). Groundlevel ozone overview. http://www.epa.gov/ozonepollution/pdfs/20141125fs-overview.pdf

EPA (n.d.). Air Quality Trends. http://www.epa.gov/airtrends/aqtrends.html#comparison).

Ito (2007) J Exposure Science and Env Epi, 17 suppl 2, S45

Jerrett,M. et al (2009). New Eng J Med 360(11): 1085-1095.

McDonnell, Stewart, and Smith (2010). Inhalation Toxicology, 22(2):160

Tolbert (2007) J Exposure Science and Env Epi 17 suppl 2 S29

Silverman (2010) J Allergy Clinical Immunology 125(2):367