Zoladz Jerzy A, Nieckarz Zenon
Department of Muscle Physiology, Institute of Basic Sciences, Faculty of Rehabilitation, University School of Physical Education, Kraków, Poland.
Experimental Computer Physics Department, Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków, Poland.
PeerJ. 2021 Jun 17;9:e11562. doi: 10.7717/peerj.11562. eCollection 2021.
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 PM, PM, PM in the respiratory tract in humans.
The PM, PM and PM 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() profile concept.
We have shown that breathing air containing 50 µg m PM (a borderline value according to the 2006 WHO standard - still valid) at minute ventilation (V) equal to 8 L min when at rest, resulted in PMdeposition rate of approximately 9 µg h, but a marathon run of an average marathon runner with the V = 62 L min increased the deposition rate up to 45 µg h. In the elite runner, marathon run with the V= 115 L min increased PM deposition rate to 83 µg h. Interestingly, breathing the air containing 50 µg mof PM at the V = 115 L minby the elite marathon runner during the race resulted in the same PMdeposition rate as the breathing highly polluted air containing as much as 466 µg m of PM when at rest. Furthermore, the total PM 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 PMin the air during a marathon race that would allow one not to exceed the PM deposition rate of 9 µg hshould be lower than 10 µg m in the case of an average runner, and it should be lower than 5.5 µg m in the case of an elite runner.
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 V generated during the race. A decrease of the PM content in the air attenuates this rate. Based on our calculations, we postulate that the PM content in the air during a involving elite marathon runners, should be below 5.5 µg m.
在过去几十年里，马拉松跑步已成为全球各地人们喜爱的体育活动形式。应当注意的是，主要的马拉松赛事都在大城市举行，那里空气质量差异很大。众所周知，呼吸污染空气会对人体产生许多有害影响。然而，尚无研究表明马拉松跑步表现对跑步者呼吸道中不同粒径空气颗粒物（PM）沉积量的影响。这就是本研究旨在确定不同空气质量下的马拉松跑步表现对人体呼吸道中PM1、PM2.5和PM10沉积的影响的原因。
基于对空气中PM含量的自行测量以及粒径分辨的沉积分数（DF）分布概念，在一名“普通跑步者”（马拉松成绩为4小时30分钟）和一名“精英马拉松跑步者”（马拉松成绩为2小时00分钟）休息时以及马拉松比赛期间，测定PM1、PM2.5和PM10的沉积情况。
我们发现，休息时分钟通气量（V̇E）等于8升/分钟，呼吸含50微克/立方米PM1（根据2006年世界卫生组织标准的临界值——仍然有效）的空气时，PM1沉积率约为9微克/小时，但普通马拉松跑步者V̇E = 62升/分钟的马拉松跑步会使沉积率提高到45微克/小时。在精英跑步者中，V̇E = 115升/分钟的马拉松跑步会使PM1沉积率提高到83微克/小时。有趣的是，精英马拉松跑步者在比赛期间V̇E = 115升/分钟呼吸含50微克/立方米PM1的空气时，PM1沉积率与休息时呼吸高达466微克/立方米的高污染空气时相同。此外，普通跑步者马拉松比赛期间呼吸道中PM的总沉积量比精英跑步者大约高22%（203/166 = 1.22）。根据我们的计算，对于普通跑步者，马拉松比赛期间空气中能使PM1沉积率不超过9微克/小时的PM1浓度应低于10微克/立方米，对于精英跑步者则应低于5.5微克/立方米。
我们得出结论，由于比赛期间产生的巨大分钟通气量，马拉松跑步会大幅提高跑步者呼吸道中空气传播PM的沉积率。空气中PM含量的降低会减弱这一沉积率。根据我们的计算，我们推测在涉及精英马拉松跑步者的比赛期间，空气中的PM含量应低于5.5微克/立方米。
