Effects of air pollution exposure on inflammatory and endurance performance in recreationally trained cyclists adapted to traffic-related air pollution

Hypertension and Elevated Pulse Pressure Responsive to Biomass Pollutants Exposures in Young Workers From the Democratic Republic of Congo: A Cross-Sectional Analysis

BACKGROUND

Occupational biomass pollutant exposure as observed in charcoal workers may have significant cardiovascular effects. This study aims to ascertain the prevalence and risk factors of hypertension and high pulse pressure (HPP), a marker of arterial stiffness, in charcoal workers compared with a control group of agricultural workers from the Democratic Republic of Congo.

METHODS AND RESULTS

The charcoal worker and agricultural worker groups (n=485; median age, 35-40 years) were composed of male charcoal producers (n=229), charcoal saleswomen (n=72), male farmers (n=118), and vegetable saleswomen (n=66). We assessed workplace air pollution, sociodemographic parameters, self-reported physical activity, body composition, exhaled air carbon monoxide, and blood pressure. Hypertension and HPP prevalences were determined. Logistic regression, adjusted for confounding variables was used to identify the risk factors. Charcoal workplaces were more polluted than agricultural workplaces (P<0.01). Charcoal producers performed higher levels of physical activity (P=0.018) and demonstrated higher levels of exhaled air carbon monoxide (P<0.0001) and pulse pressure (P=0.006), and higher prevalence of grade 1 hypertension (P=0.007), isolated systolic hypertension (P=0.04), and HPP (P=0.02) than farmers. Overall, hypertension (adjusted odds ratio [aOR], 11.76 [95% CI, 6.26-22.13]), level of particulate matter <10 μm pollutants (aOR, 1.001 [95% CI, 1.0002-1.0017]), smoking (aOR, 2.21 [95% CI, 1.15-4.24]) and low education (aOR, 2.14 [95% CI, 1.10-4.17]) were independently associated with HPP. The level of particulate matter <1.0 μm pollutants (aOR, 1.0009 [95% CI, 1.0002-1.0015]), male sex (aOR, 2.09 [95% CI, 1.21-3.64]), and job seniority (aOR, 1.022 [95% CI, 1.004-1.044]) were independently associated with isolated systolic hypertension.

CONCLUSIONS

Charcoal producers appear to develop isolated systolic hypertension and HPP more, both indices of cardiovascular events in which occupational biomass particles seem to play an early significant role.

Air Pollution and Endurance Exercise: A Systematic Review of the Potential Effects on Cardiopulmonary Health

This systematic review aimed to analyze the implications of endurance exercise in environments with certain levels of air pollution. This study was developed on the basis of the consensus of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The present review is supported by articles containing the main databases PubMed, Elsevier, and Web of Science (WoS), including scientific articles published in the last 20 years. This study highlights that exposure to air pollution during endurance activities, such as cycling and outdoor running, significantly affects cardiopulmonary health. In conclusion, while physical exercise in environments with high air pollution presents significant risks to cardiopulmonary health, implementing preventive measures and adopting public policies are crucial to minimizing these impacts and promoting safe exercise practices. Likewise, on the basis of these results, it is possible to motivate the creation of safe and natural spaces for sports practice.

Air quality, respiratory health and performance in athletes: a summary of the IOC consensus subgroup narrative review on 'Acute Respiratory Illness in Athletes'

With the WHO stating that nearly 99% of the global population is exposed to air pollution levels that increase the risk of chronic diseases, the question of exercising in polluted environments is relevant to the health of athletes. Major sporting events held under conditions of poor air quality (AQ) have highlighted the lack of answers to concerns raised by organisers and athletes about the associated health risks. This evidence-based narrative review compiles current knowledge and identifies gaps regarding the relationship between AQ and sport. It is a summary of a more comprehensive report prepared for the International Olympic Committee (IOC) Medical and Scientific Commission. This article discusses the various sources of air pollutants encountered during exercise, summarises current AQ guidelines and provides insights into AQ conditions during the Paris 2024 Olympic and Paralympic Games (OPG) as well as in Los Angeles over the past four summers, in preparation for the 2028 OPG. It also summarises the effects of air pollution on the respiratory health and performance of athletes, while proposing mitigation strategies, with a particular emphasis on AQ education.

[In defense of walking and cycling as a means of transportation in Brazil]

This essay aims to discuss walking and cycling as a means of transportation for the Brazilian population. Scientific evidence (mainly from high-income countries) shows their contributions to people's health, pointing out that these physical activities can constitute an important part of daily life and contribute to preventing diseases and to the health of municipalities by reducing air and noise pollution and the problems due to the excess of motor vehicles. We discuss the forms of measurement in national surveys and the new technologies that have been used. Trend analyses show a decrease in this type of physical activity in adults living in Brazilian capitals. However, analyzing walking and cycling together impairs interpretations and limits the study of factors associated with different types of commuting. We show that some Brazilian capitals are increasing their environmental structures, but population indicators show that groups of lower socioeconomic levels have less access to the. We discuss how much these activities are still practiced out of necessity - rather than out of choice - in Brazil due to transportation costs that remain high and unequal environments. However, most studies in Brazil being cross-sectional impairs the evaluation of possible effects on health and the influence of social variables and environmental changes on this behavior. New population surveys and longitudinal studies that support policies are essential to promote walking and cycling as a means of transportation.

Paris air quality monitoring for the 2024 Olympics and Paralympics: focus on air pollutants and pollen

BACKGROUND

Exposure to air pollution can affect the health of individuals with respiratory disease, but may also impede the health and performance of athletes. This is potentially relevant for people travelling to and competing in the Olympic and Paralympic Games (OPG) in Paris. We describe anticipated air quality in Paris based on historical monitoring data and describe the impact of the process on the development of monitoring strategies for future international sporting events.

METHODS

Air pollutant data for July to September 2020-2023 and pollen data for 2015-2022 were provided by Airparif (particulate matter (PM2.5), nitrogen dioxide (NO2) and ozone (O3)) and RNSA stations in the Paris region. Airparif's street-level numerical modelling provided spatial data for the OPG venues.

RESULTS

The maximum daily mean PM2.5 was 11±6 µg/m3 at traffic stations, below the WHO recommended daily air quality threshold (AQT). Daily NO2 concentrations ranged from 5±3 µg/m3 in rural areas to 17±14 µgm3 in urban areas. Near traffic stations, this rose to 40±24 µg/m3 exceeding the WHO AQT. Both peaked around 06:00 and 20:00 UTC (coordinated universal time). The ambient O3 level exceeded the AQT on 20 days per month and peaked at 14:00 UTC. The main allergenic taxa from June to September was Poaceae (ie, grass pollen variety).

CONCLUSION

Air pollutant levels are expected to be within accepted air quality thresholds at the Paris OPG. However, O3 concentrations may be significantly raised in very hot and clear conditions and grass pollen levels will be high, prompting a need to consider and manage this risk in susceptible individuals.

Air pollution, cardiorespiratory fitness and biomarkers of oxidative status and inflammation in the 4HAIE study

The aim of this study was to investigate the associations between cardiorespiratory fitness (CRF), long-term air pollution exposure and biochemical markers of oxidative status and inflammation. This is a cross-sectional investigation focusing on biochemical markers of oxidative status and inflammation. Participants were Caucasian (N = 1188; age 18-65 years) who lived for at least 5 years in a high air-polluted (Moravian-Silesian; MS) or low air-polluted (South Bohemia; SB) region of the Czech Republic. Healthy runners and inactive individuals were recruited. A multiple regression analysis was used to explain the relationship between multiple independent variables (CRF, trunk fat mass, sex, socioeconomic status, and region (MS region vs. SB region) and dependent variables (oxidative status, inflammation). CRF, trunk fat mass, age and sex significantly predicted almost all selected markers of oxidative status and inflammation (except GSSG, GSH/GSSG and BDNF). Participants living in the MS region presented significantly higher GPx (by 3.1%) and lower BDNF values (by 4.5%). All other investigated biochemical markers were not significantly influenced by region. We did not find meaningful interactions between long-term air-pollution exposure versus markers of oxidative status and inflammation. However, we showed various significant interactions with sex, age, CRF and body composition. The significant association of living in the high air polluted MS region with the BDNF level warrants further attention.

Exercise-Mediated Protection against Air Pollution-Induced Immune Damage: Mechanisms, Challenges, and Future Directions

Air pollution, a serious risk factor for human health, can lead to immune damage and various diseases. Long-term exposure to air pollutants can trigger oxidative stress and inflammatory responses (the main sources of immune impairment) in the body. Exercise has been shown to modulate anti-inflammatory and antioxidant statuses, enhance immune cell activity, as well as protect against immune damage caused by air pollution. However, the underlying mechanisms involved in the protective effects of exercise on pollutant-induced damage and the safe threshold for exercise in polluted environments remain elusive. In contrast to the extensive research on the pathogenesis of air pollution and the preventive role of exercise in enhancing fitness, investigations into exercise resistance to injury caused by air pollution are still in their infancy. In this review, we analyze evidence from humans, animals, and cell experiments on the combined effects of exercise and air pollution on immune health outcomes, with an emphasis on oxidative stress, inflammatory responses, and immune cells. We also propose possible mechanisms and directions for future research on exercise resistance to pollutant-induced damage in the body. Furthermore, we suggest strengthening epidemiological studies at different population levels and investigations on immune cells to guide how to determine the safety thresholds for exercise in polluted environments.

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.

The Effects of Polyphenol Supplementation on BDNF, Cytokines and Cognition in Trained Male Cyclists following Acute Ozone Exposure during High-Intensity Cycling

The neurotoxic effects of ozone exposure are related to neuroinflammation and increases in reactive oxygen species (ROS). This study aimed to assess inflammation, Brain-Derived Neurotrophic Factor (BDNF), and cognition in healthy male cyclists following polyphenol supplementation and exercise in an ozone-polluted environment. Ten male cyclists initially completed a maximal incremental test and maximal effort 4 km time trial in ambient air. Cyclists then completed two trials in an ozone-polluted environment (0.25 ppm) following 7 days of supplementation with either polyphenol (POLY) or placebo (PL). Experimental trials consisted of a three-stage submaximal test followed by a 4 km time trial. Blood samples were drawn pre- and post-exercise, and analyzed for BDNF, interleukin 6 (IL-6), interleukin 10 (IL-10) and tumor necrosis factor (TNF-α). The Stroop test and serial subtraction task were performed before ozone exposure and again after the 4 km TT. Serum BDNF increased post-exercise (p < 0.0001), and positive differences were observed post-exercise in the ozone POLY group relative to PL (p = 0.013). Plasma IL-6 increased post-exercise (p = 0.0015), and TNF-α increased post-ozone exposure (p = 0.0018). There were no differences in Stroop or serial subtraction tasks pre- or post-exercise. Exercise increases BDNF in ozone.

Air pollution and elite adolescent soccer players' performance and well-being; an observational study

INTRODUCTION

Exercising outdoors may inadvertently lead to individuals inhaling levels of air pollution that may be detrimental to their health and activity-related performance. Endurance athletes are a particularly susceptible subgroup due to their high ventilation rates sustained over prolonged periods of time coupled with high training loads that often occur outdoors. In this study, we estimate the effects of air pollution on a series of athletic performance parameters in an elite adolescent soccer team.

METHODS

External, internal, and subjective loads and wellness questionnaires were recorded for the 26 matches and 197 training sessions carried out during the 2018-19 season for a U19 team competing in Germany. Each session was combined with hourly information on the concentration of PM₁₀, O₃ and NO₂ in spatial proximity to each playing field for the duration of training or playing.

RESULTS

Increases in PM₁₀ and O₃ had significant (p <.001) associations with decreasing total distance (m) ran per session. Furthermore, increases in O₃ and NO₂ concentrations were related to an increase in average heart rate (p <.05). Moreover, increases in PM₁₀ concentration was associated with increased rating of perceived exertion (p <.001). Last, the total inhaled dose of O₃ and NO₂ over one session was linked to significant (p <.05) decreases in athletes' wellness scores on the following morning.

DISCUSSION

We find supporting evidence of the negative effects of air pollution in elite adolescent soccer players in both matches and training. The negative impacts observed on several aspects of performance are present within an elite team that regularly trained in pollution levels well within the normal ranges of what the World Health Organisation (WHO) reports to be suitable air quality. Therefore, mitigation strategies such as monitoring the air quality at the training pitch are recommended to reduce athlete exposure to air pollution even when exercising in moderate air quality.

Long-term ambient air pollution exposure and DNA methylation of peripheral brain-derived neurotrophic factor promoter

This study aimed to investigate the association between air pollutants and methylation of peripheral brain-derived neurotrophic factor (BDNF) promoters. A total of 101 individuals were recruited in this panel study. BDNF promoter methylation was detected by bisulfite-PCR amplification and pyrosequencing. Participants' exposure to air pollutants was estimated using a satellite-based random forests approach. A generalized estimated equation model with natural cubic splines was employed to examine the associations between air pollutants and BDNF promoter methylation levels. The associations between air pollution and BDNF promoter methylation showed nonlinear curves with threshold effects. The threshold concentration for the association of nitrogen dioxide (NO₂) with average methylation level was 59.7 μg/m³, and that for the association of particulate matter ≤ 1 µm in diameter (PM₁) with CpG2 methylation level was 70.9 μg/m³. The percent change of average methylation level at the 95th percentile of NO₂ against the threshold concentration was 43.25% (95%CI: 13.10%, 73.40%), and that of CpG2 methylation at the 95th percentile of PM₁ was 128.29% (95%CI: 43.27%, 213.31%). Overall, long-term exposures of PM₁, PM_2.5, PM₁₀, and NO₂ were associated with significant changes in BDNF promoter methylation levels with threshold effects.