New report quantifies health costs of high ozone on Front Range residents  

RAQC media contact: Jenn Fields, jfields@raqc.org

A new report has been completed by researchers at the Colorado School of Public Health entitled “Ozone in the Denver Metro North Front Range: A Health Impact Assessment.” The report is an analysis of the health costs of high levels of ground-level ozone on residents and communities in the Denver Metro/North Front Range ozone non-attainment area (NAA) that will inform the Regional Air Quality Council’s Control Strategy Blueprint process.

Key findings include: 

• Both the magnitude and frequency of elevated ozone concentrations are important determinants for health impacts.  

• By meeting the 70 parts per billion (ppb) ozone standard over the next five years, the communities in the nonattainment area could save an estimated $211 million to $580 million annually (in 2024 dollars) in costs associated with the health burden of ozone.  

• An increase of 10 ppb over the current observed ozone levels would bring significant additional health burdens as well as additional annual health costs of between $712 million and $1.940 billion.  

• Factors that may contribute to greater health impacts in our region include increases in ozone precursor emissions from wildfires, natural, or human-made emission sources, and increased temperatures.  

• Additional research to further refine the understanding of health risks in the Denver Metro/North Front Range associated with long-term exposure to ozone based on local data would be valuable.  

“Health impact analysis is a critical tool that serves as a bridge from health research to policy,” said study co-author Dr. Sheryl Magzamen, professor of epidemiology at Colorado State University and the Colorado School of Public Health. “Our goal as researchers was to ensure that the health impacts of ozone are considered in policy deliberations around planned actions for mitigation in our local non-attainment area.” 

“The evidence on the health risks of ozone pollution documents multiple threats to human health,” said study co-author Dr. Jonathan Samet, past dean of the Colorado School of Public Health and professor of Epidemiology and of Occupational and Environmental Health. “Our analysis builds on that evidence to show how ozone damages health in the Denver Metro/North Front Range and the benefits of reducing ozone.”

The authors used local ozone data from the Denver Metro/North Front Range and well-established modeling tools and methods to assess the health impacts of high ozone on residents of the NAA. Analysis of health impacts included asthma-related visits to the emergency department, respiratory hospitalization, minor restricted activity days, and non-accident mortality, as well as the associated costs. Their assessment estimated the attributable burden of morbidity and mortality in three scenarios in comparison to recent observed ozone values: One scenario brings the region into compliance with federal ozone standards, one examines a reduction, and the third examines an increase in ground-level ozone in the NAA: 

• Scenario 1 models avoided health impacts and costs under a reduction of ozone exposure with no daily average values above 65 ppb over a 5-year period, which is 5 ppb below the current federal standard.    

• Scenario 2 models avoided health impacts and costs when eliminating days with no daily average ozone exposure above 70 ppb over a 5-year period. In Scenario 2, the region would come into compliance with federal ozone standards.    

• Scenario 3 models additional health impacts and costs under a 10 ppb increase over the observed ozone levels over the previous 5 years.  

A health impact assessment, or HIA, is a scientific tool used by public health experts to develop approximations of outcomes based on observed data. 

“This report is a valuable resource for understanding how continued noncompliance with the ozone standard is affecting our health and economy in Colorado,” said Mike Silverstein, executive director of RAQC. “We’re grateful to the researchers for volunteering their time and expertise so we can better see the impacts ozone has on our communities.” 

The Regional Air Quality Council requested this research to better understand the health burdens and associated health costs of ozone in the region. The health impact assessment contributes to the development of the RAQC’s 2026 Control Strategy Blueprint for clean air, a strategic framework for emission-reduction strategies to achieve attainment of the 70ppb federal ozone standard set in 2015 and the resulting environmental and human health benefits. The HIA is one of several informational reports referenced in the Blueprint to inform strategies for reducing ground-level ozone to 70ppb.

Study authors Dr. Jon Samet, Dr. Sheryl Magzamen, Dr. Beth Lunsford, and Meghan Buran volunteered to conduct this research as part of their service to the community as public health experts in the Colorado School of Public Health; RAQC did not pay the authors for their work. 

Author bios

Jonathan M. Samet, a pulmonary physician and epidemiologist, is the past dean of the Colorado School of Public Health and Professor of Epidemiology and of Occupational and Environmental Health. Dr. Samet’s research has focused on the health risks posed by the environment, including inhaled pollutants and tobacco. He has served on numerous committees concerned with public health and the environment: the U.S. EPA Science Advisory Board, chairing the Clean Air Scientific Advisory Committee; committees of the National Academies, including chairing the Biological Effects of Ionizing Radiation VI Committee, the Committee on Research Priorities for Airborne Particulate Matter, the Committee to Review the IRIS Process, and the Board on Environmental Studies and Toxicology, among others; and the National Cancer Advisory Board. He is a member of the National Academy of Medicine and recipient of the David Rall Medal for his contributions. He received the Trudeau Medal from the American Thoracic Society, the Haagen-Smit Award from the California Air Resources Board, and the Fries Prize for Improving Health. Dr. Samet received his MD from the University of Rochester, School of Medicine and Dentistry, and his master’s degree in epidemiology from the Harvard T.H. Chan School of Public Health. 

Sheryl Magzamen is a professor in the Department of Environmental and Radiological Health Sciences at Colorado State University and in the Department of Epidemiology at the Colorado School of Public Health. Trained as a respiratory epidemiologist, Dr. Magzamen’s primary research is understanding the relative contribution of social factors and environmental exposures on the development and morbidity related to chronic respiratory disease. As part of her research program, Dr. Magzamen focuses on a range of indoor and outdoor sources of air pollution, including wildfire smoke, traffic-related air pollution, bioaerosols, and chemical mixtures. Dr. Magzamen received her MPH in health policy from Emory and her PhD in epidemiology from Berkeley.