Ambient air pollution and human performance: Contemporaneous and acclimatization effects of ozone exposure on athletic performance

Environmental challenges facing athletes, stakeholders and spectators at Paris 2024 Olympic and Paralympic Games: an evidence-based review of mitigation strategies and recommendations

The upcoming Paris 2024 Olympic and Paralympic Games could face environmental challenges related to heat, air quality and water quality. These challenges will pose potential threats to athletes and impact thousands of stakeholders and millions of spectators. Recognising the multifaceted nature of these challenges, a range of strategies will be essential for mitigating adverse effects on participants, stakeholders and spectators alike. From personalised interventions for athletes and attendees to comprehensive measures implemented by organisers, a holistic approach is crucial to address these challenges and the possible interplay of heat, air and water quality factors during the event. This evidence-based review highlights various environmental challenges anticipated at Paris 2024, offering strategies applicable to athletes, stakeholders and spectators. Additionally, it provides recommendations for Local Organising Committees and the International Olympic Committee that may be applicable to future Games. In summary, the review offers solutions for consideration by the stakeholders responsible for and affected by the anticipated environmental challenges at Paris 2024.

Physiological impacts of atmospheric pollution: Effects of environmental air pollution on exercise

In this review, we discuss some of the recent advances in our understanding of the physiology of the air pollution and exercise. The key areas covered include the effect of exercise intensity, the effects of pre-exposure to air pollution, acclimation to air pollution, and the utility of masks during exercise. Although higher intensity exercise leads to an increase in the inhaled dose of pollutants for a given distance traveled, the acute effects of (diesel exhaust) air pollution do not appear to be more pronounced. Second, exposure to air pollution outside of exercise bouts seems to have an effect on exercise response, although little research has examined this relationship. Third, humans appear to have an ability to acclimate to ground level ozone, but not other pollutants. And finally, masks may have beneficial effects on certain outcomes at low intensity exercise in pollution with significant levels of particles, but more study is required in realistic conditions.

Association between gestational exposure and risk of orofacial clefts: a systematic review and meta-analysis

BACKGROUND

The occurrence of orofacial Clefts (OFCs) is a congenital disease caused by many factors. According to recent studies, air pollution has a strong correlation with the occurrence of OFCs. However, there are still some controversies about the current research results, and there is no relevant research to review the latest results in recent years.

OBJECTIVE

In this paper, the authors conducted a systematic review and meta-analysis to explore the correlation between ambient air pollution and the occurrence of neonatal OFCs deformity.

METHODS

We searched Pubmed, Web of science, and Embase databases from the establishment of the database to May 2023. We included observational studies on the relationship between prenatal exposure to fine particulate matter 2.5 (PM2.5), fine particulate matter 10 (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO) and the risk of cleft lip (CL), cleft palate (CP), cleft lip with or without palate (CL/P). the Newcastle-Ottawa quality assessment scale (NOS) was used to evaluate the quality of the literature. Funnel plot and Egger's regression were used to verify the publication bias. Random effect model or fixed effect model was used to estimate the combined relative risk (RR) and 95% confidence interval (95%CI).

RESULTS

A total of eleven studies were included in this study, including four cohort studies and seven case-control studies, including 22,453 cases of OFCs. Ten studies had low risk of bias and only one study had high risk of bias. Three studies reported that PM2.5 was positively correlated with CL and CP, with a combined RR and 95%CI of 1.287(1.174,1.411) and 1.267 (1.105,1.454). Two studies reported a positive correlation between O3 and CL, with a combined RR and 95%CI of 1.132(1.047,1.225). Two studies reported a positive correlation between PM10 and CL, with a combined RR and 95%CI of 1.108 (1.017,1.206). No association was found between SO2, CO, NO2 exposure during pregnancy and the risk of OFCs.

CONCLUSION

The results of this study showed that there was a significant statistical correlation between exposure to PM10, PM2.5, O3 and the risk of OFCs in the second month of pregnancy. Exposure assessment, research methods and mechanisms need to be further explored.

Air quality and employee performance in teams: Evidence from the NFL

Emerging research documents the impact of poor air quality on employee performance in a number of settings, including sport. Unlike other settings, sports teams have limited ability to influence previously scheduled games, making air quality exogenous to unobservable factors affecting game outcomes. We link play-level data from National Football League (NFL) games to data from air quality monitoring stations located near NFL stadiums. Results using data from about 90,000 offensive plays in 900 NFL games indicate that yards gained per offensive play increase with PM2.5 concentration. Defensive players are relatively more affected by air quality than offensive players.

Impact of air pollution on running performance

Air pollution exposures during training may impact race preformances. We aggregated data on 334 collegiate male track & field athletes from 46 universities across the United States over 2010-2014. Using distributed lag non-linear models, we analyzed the relationship between race time and PM2.5, ozone, and two versions of the Air Quality Index (AQI) exposures up to 21 days prior to the race. We observed a 12.8 (95% CI: 1.3, 24.2) second and 11.5 (95% CI: 0.8, 22.1) second increase in race times from 21 days of PM2.5 exposure (10.0 versus 5.0 μg/m3) and ozone exposure (54.9 versus 36.9 ppm), respectively. Exposure measured by the two-pollutant threshold (PM2.5 and ozone) AQI was not significantly associated with race time; however, the association for summed two-pollutant AQI (PM2.5 plus ozone) was similar to associations observed for the individual pollutants (12.4, 95% CI: 1.8, 23.0 s). Training and competing at elevated air pollution levels, even at exposures within AQI's good-to-moderate classifications, was associated with slower race times. This work provides an initial characterization of the effect of air pollution on running performance and a justification for why coaches should consider approaches to reduce air pollution exposures while training.

Personal strategies to mitigate the effects of air pollution exposure during sport and exercise: a narrative review and position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology

Air pollution is among the leading environmental threats to health around the world today, particularly in the context of sports and exercise. With the effects of air pollution, pollution episodes (eg, wildfire conflagrations) and climate change becoming increasingly apparent to the general population, so have their impacts on sport and exercise. As such, there has been growing interest in the sporting community (ie, athletes, coaches, and sports science and medicine team members) in practical personal-level actions to reduce the exposure to and risk of air pollution. Limited evidence suggests the following strategies may be employed: minimising all exposures by time and distance, monitoring air pollution conditions for locations of interest, limiting outdoor exercise, using acclimation protocols, wearing N95 face masks and using antioxidant supplementation. The overarching purpose of this position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology is to detail the current state of evidence and provide recommendations on implementing these personal strategies in preventing and mitigating the adverse health and performance effects of air pollution exposure during exercise while recognising the limited evidence base.

Air pollution and individual productivity: Evidence from the Ironman Triathlon results

The study considers how air quality affects the productivity of physically intensive labor. Namely, we analyze the athletes of the Ironman Triathlon, one of the toughest long-distance triathlon races in the world. Moreover, in this competition, both men and women, professional and amateur athletes, can participate. We consider the results of Ironman Triathlon from 2005 to 2019. Using athlete's finishing time as a dependent variable, we estimate the impact of concentrations of two main air pollutants, O3 and PM2.5. We found triathletes performance decrements in swimming due to high ozone concentration and in bicycle riding and running due to high level of PM2.5. We have also found that professional athletes are less sensitive to air pollution, whereas there is almost no gender difference in the impact of air pollution on athletes' productivity.

Influence and Mechanisms of Action of Environmental Stimuli on Work Near and Above the Severe Domain Boundary (Critical Power)

Abstract

The critical power (CP) concept represents the uppermost rate of steady state aerobic metabolism during work. Work above CP is limited by a fixed capacity (W′) with exercise intensity being an accelerant of its depletion rate. Exercise at CP is a considerable insult to homeostasis and any work done above it will rapidly become intolerable. Humans live and exercise in situations of hypoxia, heat, cold and air pollution all of which impose a new environmental stress in addition to that of exercise. Hypoxia disrupts the oxygen cascade and consequently aerobic energy production, whereas heat impacts the circulatory system’s ability to solely support exercise performance. Cold lowers efficiency and increases the metabolic cost of exercise, whereas air pollution negatively impacts the respiratory system. This review will examine the effects imposed by environmental conditions on CP and W′ and describe the key physiological mechanisms which are affected by the environment.

Graphical Abstract

Impact of ambient air pollution on outdoor employees’ performance: Mediating role of anxiety

This paper aims to examine the direct and indirect impact of ambient air pollution (AAP) on employees’ performance. This study has used cross sectional survey design to collect the data from the outdoor employees of the pharmaceutical industry of Pakistan. The data were collected in time lags from 299. Partial least squares- structural equation modeling (PLS-SEM) approach was applied to analyze the data. The results show that AAP has a significant negative impact on the employees’ performance, and anxiety partially mediates the association between AAP and employees’ performance. This study reveals that AAP brings anxiety among outdoor employees, which in turn decreases their working performance. The implications, limitations, and future research directions are presented in the last section of this study.

Acute exercise in ozone-polluted air induces apoptosis in rat quadriceps femoris muscle cells via mitochondrial pathway

Ozone (O₃) pollution can decrease sport performance and induce respiratory toxicity, but relatively few studies have investigated its effects on skeletal muscles. We randomly assigned rats to the following groups based on a 2 ​× ​4 two-factor factorial design: Air+0, Air+10, Air+15, and Air+20, O₃+0, O₃+10, O₃+15, and O₃+20. The rats in the +0 groups rested, whereas those in the +10, +15, and +20 groups ran on a treadmill (in clean air for Air groups and in air polluted with 0.14 ​parts per million [ppm] O₃ for O₃ groups) at speeds of 10, 15, and 20 ​m/min, respectively, for 1 ​h. Thereafter, key enzyme activities involving the tricarboxylic acid cycle, oxidative phosphorylation, adenosine triphosphate (ATP) content, histopathological changes, oxidative stress, inflammation factors, and apoptosis were assessed in the rat quadriceps femoris samples. Ozone reduced key enzyme activities and ATP contents in the quadriceps femoris regardless of whether the rats exercised. Pathological changes, inflammatory factors, oxidative stress, and mitochondria-dependent apoptosis were only evident under conditions of exercise combined with ozone and increasingly worsened as exercise intensity increased. These findings suggested that acute exercise under ozone exposure could induce damage to the quadriceps femoris, which would negatively affect sport performance. Ozone-induced disrupted energy metabolism might be an early event that becomes more critical as exercise intensity increases. Therefore, care should be taken when exercising in polluted air, even when ozone pollution is mild.

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O₃ itself inhibited key enzyme activities in TCA and oxidative phosphorylation.

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O₃ decreased ATP production regardless of whether it was coupled with exercise.

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Acute exercise in O₃ polluted air induced oxidative stress, inflammatory reaction.

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Acute exercise in O₃ polluted air caused mitochondria-mediated apoptosis.

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O₃ and exercise synergistically regulated levels of IL-2, IL-6 and 8-OHdG in muscles.

Horse Racing as a Model to Study the Relationship between Air Pollutants and Physical Performance

Simple Summary

Ambient air contains a mixture of pollutants, the effects of which on animal and human health have been widely described. In contrast, the effects on physical performance are poorly understood, largely due to the difficulty of implementing an experimental model to study this problem. Thoroughbred horse racing involves many animal athletes, of similar genetics, environmental exposure, training, and diet, who participate by breathing varying mixtures of ambient air. This paper presents an analysis strategy based on the homogeneity of the races, the distance, and the design of the track. This paper presents a preliminary analysis in which we observe that the level of performance is decreased by concentrations of PM₁₀, PM_2.5, NO₂, NO, and CO in the air. Thus, we note that this natural experiment may constitute a model of interest to advance the understanding of the problem.

Abstract

This study proposes the theoretical principles for the selection of a sample of horse races to study the relationship between air pollutants and performance. These criteria were then applied to an original dataset comparing the correlations between these variables obtained in “Handicap” versus “Conditional” type races. Methods: The mean concentration of pollutants during the six hours prior to the race and the speed of the test were determined in 441 official races at a racecourse in Santiago, Chile, during the summer and winter months of 2012. Using layout, track condition and distance (1000, 1100 and 1200 m) as criteria, a homogeneous group of races (“Handicap”; n = 214) versus a heterogeneous group (“Conditional”; n = 95) were compared using simple correlations (Spearman’s test). Results: Race speed was related to greater levels of PM₁₀, PM_2.5, NO₂, NO and SO₂ and it was positively related to O₃, a trend that was observed in the 1000, 1100 m races and in the total “Handicap” group. Similar results were observed only in 1000 m for the “Conditional” group with lower Rho, except for PM₁₀ and PM_2.5. The total races of the conditional group showed lower Rho values and significant associations of the same trend for CO, NO₂, NO and SO₂. Conclusions: Horse races between 1000 and 1200 m of the “Handicap” type appear to be an interesting group to study the relationship between air pollutants and the performance of racehorses. In the future, our observations should be expanded to other distances and other types of races.

Pollution at schools and children's aerobic capacity

Poor respiratory health is a major cause of mortality and morbidity worldwide, and children are especially vulnerable. Existing research in economics has documented the effect of pollution on severe health outcomes, such as hospitalizations for asthma and infant death. However, evidence on the effect of air pollution on less extreme measures of respiratory health is limited, because these effects are difficult to measure. Using a more sensitive measure, aerobic capacity ( VO2max ), I study the impact of air pollution on respiratory performance of children. I combine school-grade level data from the California Physical Fitness Test from 2009 to 2017 with local air pollution and weather data to estimate the impact on student aerobic capacity of fluctuations in air pollution levels on testing days. Ozone affects child aerobic capacity at levels even below the Environmental Protection Agency thresholds.

Negative Air Ions in Neuropsychiatric Disorders

BACKGROUND

Air ions (AIs) are clusters of ionized particles present in the atmosphere, carrying an electrical charge of negative or positive polarity. Past speculations suggested that exposure to positive air ions may be harmful, while exposure to negative air ions (NAIs) may be associated with beneficial health effects. Increasing attention has been directed towards investigating the potential effect of NAIs on human brain activities since initial observations of their beneficial effects on some cognitive processes and mood.

AIMS

Given the paucity and scattered literature, our paper aims to review the available studies on potential positive effects of NAIs exposure on cognitive performances and depression.

DISCUSSION

The review of the literature seems to confirm the effects of NAIs on several brain functions. Indeed, a significant association between NAIs exposure and both well-being and high cognitive performances has been described. Furthermore, exposure to high concentrations of NAIs could be related to the improvement of depressive symptoms.

CONCLUSION

A growing evidence of data, although not yet conclusive, would suggest that NAIs might improve cognitive processes. These findings require specific and urgent controlled trials adopting systems based on AIs release to possibly prevent and treat cognitive dysfunctions present in a broad range of neuropsychiatric conditions.

Human exposure to air contaminants in sports environments

The aim of this review was to investigate human exposure to relevant indoor air contaminants, predictors affecting the levels, and the means to reduce the harmful exposure in indoor sports facilities. Our study revealed that the contaminants of primary concern are the following: particulate matter in indoor climbing, golf, and horse riding facilities; carbon dioxide and particulate matter in fitness centers, gymnasiums, and sports halls; Staphylococci on gymnasium surfaces; nitrogen dioxide and carbon monoxide in ice hockey arenas; carbon monoxide, nitrogen oxide(s), and particulate matter in motor sports arenas; and disinfection by-products in indoor chlorinated swimming pools. Means to reduce human exposure to indoor contaminants include the following: adequate mechanical ventilation with filters, suitable cleaning practices, a limited number of occupants in fitness centers and gymnasiums, the use of electric resurfacers instead of the engine powered resurfacers in ice hockey arenas, carefully regulated chlorine and temperature levels in indoor swimming pools, properly ventilated pools, and good personal hygiene. Because of the large number of susceptible people in these facilities, as well as all active people having an increased respiratory rate and airflow velocity, strict air quality requirements in indoor sports facilities should be maintained.

Human exposure to ozone in school and office indoor environments

BACKGROUND

Although it is recognized that ozone causes acute and chronic health effects and that even trace amounts of ozone are potentially deleterious to human health, information about global and local exposures to ozone in different indoor environments is limited. To synthesize the existing knowledge, this review analyzes the magnitude of and the trends in global and local exposure to ozone in schools and offices and the factors controlling the exposures.

METHODS

In conducting the literature review, Web of Science, SCOPUS, Google Scholar, and PubMed were searched using 38 search terms and their combinations to identify manuscripts, reports, and directives published between 1973 and 2018. The search was then extended to the reference lists of relevant articles.

RESULTS

The calculated median concentration of ozone both in school (8.50 μg/m³) and office (9.04 μg/m³) settings was well below the WHO guideline value of 100 μg/m³ as a maximum 8 h mean concentration. However, a large range of average concentrations of ozone was reported, from 0.8-114 μg/m³ and from 0 to 96.8 μg/m³ for school and office environments, respectively, indicating situations where the WHO values are exceeded. Outdoor ozone penetrating into the indoor environment is the main source of indoor ozone, with median I/O ratios of 0.21 and 0.29 in school and office environments, respectively. The absence of major indoor ozone sources and ozone sinks, including gas-phase reactions and deposition, are the reasons for lower indoor than outdoor ozone concentrations. However, there are indoor sources of ozone that are of significance in certain indoor environments, including printers, photocopiers, and many other devices and appliances designed for indoor use (e.g., air cleaners), that release ozone either intentionally or unintentionally. Due to significantly elevated outdoor ozone concentrations during summer, summer indoor concentrations are typically elevated. In addition, the age of a building and various housing aspects (carpeting, air conditioning, window fans, and window openings) have been significantly associated with indoor ozone levels.

CONCLUSIONS

The existing means for reducing ozone and ozone reaction products in school and office settings are as follows: 1) reduce penetration of outdoor ozone indoors by filtering ozone from the supply air; 2) limit the use of printers, photocopiers, and other devices and appliances that emit ozone indoors; 3) limit gas-phase reactions by limiting the use of materials and products (e.g. cleaning chemicals) the emissions of which react with ozone.