A photo of Patrick Ryan.

Patrick H. Ryan, PhD, MS

  • Professor, UC Department of Pediatrics
  • UC Department of Environmental Health



My research involves assessing environmental exposures, particularly air pollutants, and studying how they affect pediatric respiratory health and neurodevelopment. My research primarily involves:

  • Air pollution
  • The built environment including greenspace
  • The use of personal monitors and sensors to measure environmental exposures
  • Environmental asbestos exposure

The goals of my research are to answer the following questions: 1) How do we accurately characterize exposure to environmental pollutants, especially air pollutants; and 2) What is the impact or health effects of environmental exposures, especially air pollutants?

Early in my career, I developed the first land-use regression model of elemental carbon, a traffic-related pollutant. This model has been widely applied and used in the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) to assess childhood exposure to traffic-related air pollution with childhood wheezing, asthma onset and other respiratory diseases. More recently, we have linked traffic-related air pollution to childhood mental health, including anxiety and depression.

My focus on air pollution has also led to community-based research to study air quality and local schools, to demonstrate the effectiveness of anti-idling campaigns on improving air quality near schools. In addition, I have collaborated with engineers to develop personal monitors for air pollution, including ultrafine particles. My research group is currently utilizing these personal monitors to measure adolescents’ personal exposure to air pollution and understand how they impact respiratory health.

Other research interests include the identification of environmental, demographic, home and other factors associated with personal exposure to specific elemental constituents of particulate matter and the impact of naturally occurring elongated mineral fibers (e.g. asbestos) on respiratory and autoimmune disease in the western United States.

My research has been supported by local and national organizations, including the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), the Environmental Protection Agency (EPA) and the Health Effects Institute (HEI). The results of these research efforts have been published in more than 100 peer-reviewed papers.

Locally, I serve on multiple mentoring committees including clinical fellows, K recipients and junior faculty. I also currently serve as the co-director of the MS in Clinical and Translational Research program and the director of Translational Workforce Development for the Center for Clinical and Translational Science and Training at Cincinnati Children’s.


Impact of Personal, Sub-hourly Exposure to Ultrafine Particles on Respiratory Health in Adolescents With Asthma. Turner, AL; Brokamp, C; Wolfe, C; Reponen, T; Ryan, PH. Annals of the American Thoracic Society. 2022.

Fluoride exposure during early adolescence and its association with internalizing symptoms. Adkins, EA; Yolton, K; Strawn, JR; Lippert, F; Ryan, PH; Brunst, KJ. Environmental Research. 2022; 204.

Residential bacteria and fungi identified by high-throughput sequencing and childhood respiratory health. Cox, J; Stone, T; Ryan, P; Burkle, J; Jandarov, R; Mendell, MJ; Niemeier-Walsh, C; Reponen, T. Environmental Research. 2022; 204.

Source-specific contributions of particulate matter to asthma-related pediatric emergency department utilization. Bhuiyan, MA N; Ryan, P; Oroumyeh, F; Jathan, Y; Roy, M; Balachandran, S; Brokamp, C. Health Information Science and Systems. 2021; 9.

Pediatric asthma incidence rates in the United States from 1980 to 2017. Johnson, CC; Havstad, SL; Ownby, DR; Joseph, CL M; Sitarik, AR; Biagini Myers, J; Gebretsadik, T; Hartert, TV; Khurana Hershey, GK; Jackson, DJ; et al. Journal of Allergy and Clinical Immunology. 2021; 148:1270-1280.

Personal exposure to average weekly ultrafine particles, lung function, and respiratory symptoms in asthmatic and non-asthmatic adolescents. Turner, A; Brokamp, C; Wolfe, C; Reponen, T; Ryan, P. Environmental International. 2021; 156.

Seasonal variation of lung function in cystic fibrosis: longitudinal modeling to compare a Midwest US cohort to international populations. Gecili, E; Brokamp, C; Palipana, A; Huang, R; Andrinopoulou, ER; Pestian, T; Rasnick, E; Keogh, RH; Ni, Y; Clancy, JP; et al. Science of the Total Environment. 2021; 776.

Exposure to traffic-related air pollution and bacterial diversity in the lower respiratory tract of children. Niemeier-Walsh, C; Ryan, PH; Meller, J; Ollberding, NJ; Adhikari, A; Reponen, T. PLoS ONE. 2021; 16.

Seasonality, mediation and comparison (SMAC) methods to identify influences on lung function decline. Gecili, E; Palipana, A; Brokamp, C; Huang, R; Andrinopoulou, ER; Pestian, T; Rasnick, E; Keogh, RH; Ni, Y; Clancy, JP; et al. MethodsX. 2021; 8.

NAT1 genetic variation increases asthma risk in children with secondhand smoke exposure. Brooks, CC; Martin, LJ; Pilipenko, V; He, H; LeMasters, GK; Lockey, JE; Bernstein, DI; Ryan, PH; Hershey, GK K; Myers, JM B. The Journal of asthma research. 2021; 58:284-292.

From the Blog

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Patrick H. Ryan, PhD, MS3/28/2022