Consortium Statement on the EPA decision not to improve the National Ozone Standard

Testimony for Docket ID No. EPA-HQ-OAR-2018-0279

Respected EPA panelists and fellow citizens. My name is Mona Sarfaty. I am a physician trained in family medicine and public health. I practiced primary care medicine and taught medical and public health students in three different academic medical centers over a 35-year period. Today, I am the Executive Director of the Medical Society Consortium on Climate and Health, a group of 29 national medical societies that inform the public and policymakers about the health emergency of climate change and the health benefits of climate solutions. The Consortium also has 55 public health affiliates that share our concerns about the climate crisis and our efforts to address it with solutions that benefit health. One of those concerns is that global warming causes an elevation of ground-level ozone, which is an irritating oxidizing agent that causes a range of measurable health harms. Addressing ozone by reducing the ambient levels will reflect progress we make as a society in reducing emissions of greenhouse gases. Progress in reducing the emissions of greenhouse gases will directly benefit health and the climate. This is because Climate Solutions are Health Solutions.

We oppose the proposal to leave the National Ambient Standard for Ozone where it is. We support the recommendation of the American Lung Association to strengthen the standard to no higher than 60 parts per billion (ppb). There are personal and professional reasons that I weigh in today on the national ambient ozone standard.

I will never forget what it felt like to play tennis on days when the ozone level was high. Years ago, I worked for a summer in Pasadena, California when smog was so severe that I didn’t even know that a 5,000 foot mountain called Mt. Wilson was standing tall in full view of downtown. I could not see this mountain on days when the ozone level was high. While playing tennis, I experienced an annoying pain in my chest, which did not seem to be related to my tennis swing or the movement of running around the court. I later discovered that a high ozone level was the explanation because it happened again on several occasions–but only on days when the ozone level was high. Years later I learned that those high ozone days were impacting the lungs of children with asthma and causing more emergency room visits and hospitalizations.

It isn’t only children who are affected. A study published in 2017 in JAMA involving the entire Medicare population found that increases in ozone exposure from 2000 to 2012 were associated with increases in daily death tolls throughout the 12-year period.1 Simply put, ozone exposure raised daily deaths in the Medicare population.

More recently, we learned from a study published in JAMA in 2019 that ozone harms the structure of the lungs in older individuals who have emphysema. Longitudinal exposure to ambient pollutants and especially ozone over a 10-year period was associated with greater loss of lung function. CT scanning found increased destruction of lung tissue in the people who had emphysema.2 The adverse impact on people who experience this is real and costly to them and their families–and to society as a whole since everyone shares the cost of providing medical care.

A striking feature of this study which was conducted in different parts of the country is that ozone levels did not decline from 2000 to 2018. This is additionally troubling at a time when the public’s attention has been turned to the structural features of our society that have reduced the health of African Americans and other minority populations. It should be noted that ozone is most elevated in areas with the largest concentration of people of color. About a year ago, the Consortium and many other health organizations released a Call to Action on Climate, Health, and Equity: A Policy Action Agenda. It calls for 10 policies that will protect the climate and our health and protect those who are most vulnerable by lowering pollution levels and reducing the damage to our climate. Today that agenda is endorsed by over 150 organizations of medicine, nursing, and public health, academic institutions representing those 3 disciplines, and over 500 hospitals (see To properly protect and improve everyone’s health including the health of those who suffer disproportionately from air pollution and environmental injustice, we must increase our national efforts to improve air quality. The ozone standard is one key part of this effort.

While the evidence on the danger of ozone pollution has become stronger, so has the evidence on the benefits of reducing exposure. We know from specific experiences that the real-time short-term benefits from reduced ozone are measurable. A natural experiment occurred in Atlanta in 1996 at the time of the Olympics. The traffic restrictions in the city at that time caused a dramatic 28% fall in the ozone level compared to a typical day–and a resulting dramatic drop in hospital admissions (19-41%) for asthma attacks as reported by the main databases of claims. This drop in admissions did not occur for other diagnoses.3

Other pediatric respiratory effects have well-documented associations with ozone: namely increased asthma hospitalization, asthma medication use, increased symptoms, and increased missed school days. These documented health effects from ozone as well as a narrow definition for the baseline rates (i.e., excluding diagnoses of wheezing in young children) make these projections inherently conservative regarding the overall burden of disease from ozone.4

As the temperature rises, so will the ozone concentration. Many people believe that air quality has improved so dramatically that no further improvement in regulations is necessary. This conclusion is not warranted. A more vigorous approach and more protective standard will benefit the health of our population and reduce the health care costs for the country–and reflect efforts to take global warming seriously.


1. Di Q, Dai L, Wang Y, et al. Association of Short-term Exposure to Air Pollution With Mortality in Older Adults. JAMA. 2017;318(24):2446–2456. doi:10.1001/jama.2017.17923
2. Wang M, Aaron CP, Madrigano J, et al. Association Between Long-term Exposure to Ambient Air Pollution and Change in Quantitatively Assessed Emphysema and Lung Function. JAMA. 2019;322(6):546–556. doi:10.1001/jama.2019.10255
3. Friedman MS, Powell KE, Hutwagner L, Graham LM, Teague WG. Impact of Changes in Transportation and Commuting Behaviors During the 1996 Summer Olympic Games in Atlanta on Air Quality and Childhood Asthma. JAMA. 2001;285(7):897–905. doi:10.1001/jama.285.7.897
4. Ibid.