Marr's findings come from a comprehensive study that evaluated marathon race results, weather data, and air pollutant concentrations in seven marathons over a period of eight to 28 years. The top three male and female finishing times were compared with the course record and contrasted with air pollutant levels, taking high temperatures that were detrimental to performance into consideration.

Higher levels of particles in the air were associated with slower running times for women, while men were not significantly affected, Marr said. The difference may be due to the smaller size of women's tracheas, which makes it easier for certain particles to deposit there and possibly to cause irritation

"Although pollution levels in these marathons rarely exceeded national standards for air quality, performance was still affected," Marr said.

Her work, done in collaboration with Matthew Ely, an exercise physiologist at the U.S. Army Research Institute of Environmental Medicine, appears in the official journal of the American College of Sports Medicine, Medicine and Science in Sports & Exercise.

Her studies were conducted where major U.S. marathons are located, such as New York, Boston, and Los Angeles, where pollution tends to be highest. Although the person might not be significantly impacted by low-yet-still-acceptable air quality, marathoners are atypical because of their breathing patterns, she said.

"Previous research has shown that during a race, marathon runners inhale and exhale about the same volume of air as a sedentary person would over the course of two full days," Marr said. "Therefore, runners are exposed to much greater amounts of pollutants than under typical breathing conditions."

Particulate matter appeared to be the only performance-altering factor in air quality, with carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide levels not impacting race times.

Marr is a member of the national Center for Environmental Implications of NanoTechnology, funded by the National Science Foundation. This center is dedicated to determining the relationship between a vast array of nanomaterials and their potential consequences for the environment.

She is also a past recipient of the National Science Foundation (NSF) Faculty Early Career Development Program Award, supporting her work with air pollution, particularly how to measure air pollutant emissions.

Note: If no author is given, the source is cited instead.

• Fitness
• Menopause
• Sports Medicine

• Air Quality
• Air Pollution
• Pollution

• Marathon
• Anaerobic exercise
• Physical exercise
• Aerobic exercise
• Tropospheric ozone
• Atmospheric dispersion modeling