Marathon race performance increases the amount of particulate matter deposited in the respiratory system of runners: an incentive for “clean air marathon runs”

Abstract

Background In the last decades, marathon running has become a popular form of physical activity among people around the world. It should be noticed that the main marathon races are performed in large cities, where air quality varies considerably. It is well established that breathing polluted air results in a number of harmful effects to the human body. However, there have been no studies to show the impact of marathon run performance on the amount of the deposition of varied fractions of airborne particulate matter (PM) in the respiratory tract of runners. This is why the present study sought to determine the impact of marathon run performance in the air of varying quality on the deposition of the PM1, PM2.5, PM10 in the respiratory tract in humans. Methods The PM1, PM2.5 and PM10 deposition was determined in an “average runner” (with marathon performance time 4 h: 30 min) and in an “elite marathon runner” (with marathon performance time 2 h: 00 min) at rest, and during a marathon race, based on own measurements of the PM content in the air and the size-resolved DF(d) profile concept. Results We have shown that breathing air containing 50 µg m−3 PM10 (a borderline value according to the 2006 WHO standard - still valid) at minute ventilation (VE) equal to 8 L min−1 when at rest, resulted in PM10deposition rate of approximately 9 µg h−1, but a marathon run of an average marathon runner with the VE = 62 L min−1 increased the deposition rate up to 45 µg h−1. In the elite runner, marathon run with the VE= 115 L min−1 increased PM10 deposition rate to 83 µg h−1. Interestingly, breathing the air containing 50 µg m−3of PM10 at the VE = 115 L min−1by the elite marathon runner during the race resulted in the same PM10deposition rate as the breathing highly polluted air containing as much as 466 µg m−3 of PM10 when at rest. Furthermore, the total PM10 deposition in the respiratory tract during a marathon race in average runners is about 22% greater (203 / 166 = 1.22) than in elite runners. According to our calculations, the concentration of PM10in the air during a marathon race that would allow one not to exceed the PM10 deposition rate of 9 µg h−1should be lower than 10 µg m−3 in the case of an average runner, and it should be lower than 5.5 µg m−3 in the case of an elite runner. Conclusions We conclude that a marathon run drastically increases the rate of deposition of the airborne PM in the respiratory tract of the runners, as a consequence of the huge VE generated during the race. A decrease of the PM content in the air attenuates this rate. Based on our calculations, we postulate that the PM10 content in the air during a “clean air marathon run”, involving elite marathon runners, should be below 5.5 µg m−3.

Factors Influencing Running Performance During a Marathon: Breaking the 2-h Barrier

“…The best records of the marathon runs were achieved in spring or autumn, early in the morning and with an external temperature between 10 and 15°C ( 25 ). Recently it has been shown as airborne particulate matter (PM 10 ) can settle in the airways of runners ( 26 ). The main marathons take place in large, generally highly polluted cities.…”

“…Air pollution can reduce the marathon performance, at least in women (every 10 μg m −3 in PM 10 , performance decrease by 1.4%) ( 27 ), as well as having a negative impact on health. To ensure “clean air” for elite runners, the PM content should be <5.5 μg m −3 ( 26 ).…”

Emerging concern on air pollution and health: Trade-off between air pollution exposure and physical activity

“…Zoladz et al. found that PM 10 deposition in marathon runners was 6–10 times higher than those at rest [ 22 ]. Therefore, the public is more likely to be exposed to air pollution during outdoor physical activity.…”

Air Quality Sensors Systems as Tools to Support Guidance in Athletics Stadia for Elite and Recreational Athletes

“…; [ 14 ]). This is explained by the greater fraction of air inhaled during exercise, effectively bypassing the normal nasal filtration mechanisms in the case of particles, and the increased airflow velocity, carrying pollutants deeper into the respiratory tract [ 15 , 16 , 17 , 18 ].…”