Posted on No Comments on But we’re only human: Heroic Olympians no exception to water pollution health effects

But we’re only human: Heroic Olympians no exception to water pollution health effects

Remember the previous instalment of our ‘But we’re only human’ series, where we talked about the health impacts of air pollution on Olympic athletes? Today, we will be covering something similar for water pollution by drawing on two controversial case studies: the 2016 Rio and 2018 Pyeongchang Olympic Games.  

Gastrointestinal illnesses are most commonly observed amongst water sports athletes, which is unsurprising as disease-causing microorganisms can easily enter the human body through the eyes or mouth, and are highly resistant (Staggemeier et al., 2017). This is especially so for enteric viruses such as rotavirus and adenovirus, which are found in untreated human sewage and notorious for their stability in the gastrointestinal tract (Staggemeier et al., 2017). In a study conducted by Bosch et al. (2008), 105 to 1013 enteric virus particles were detected per gram of stool amongst infected persons, reflecting their infectiousness and ability to resist antibodies. Therefore, while enteric viruses normally do not result in acute infection or mortality (Weidner and Sevier, 1996), they remain a cause for concern as they can persist for long durations and “easily knock athlete[s] out of competition”.

Enteric viruses are responsible for causing gastrointestinal illnesses amongst athletes, as they are often found in water contaminated by untreated sewage (Bosch, Pintó and Abad, 2006)

In fact, enteric viruses came under the spotlight at the 2016 Rio Olympic Games, where 13 American athletes fell ill with gastroenteritis-related symptoms including diarrhoea and vomiting after a test rowing event. According to the American team doctor, this could have occurred after water in the training venue dripped onto athletes’ water bottles, causing their drinking water to become contaminated. This was a sentiment shared by World Health Organisation officials, who classified Rio de Janeiro’s water quality as poor or very poor, and strongly urged local virologists to conduct testing for enteric viruses. While subsequent studies revealed that only 1% of competing athletes contracted gastroenteritis during the actual event (Soligard et al., 2017), the presence of infection nonetheless reflected that enteric viruses were a threat to human health. 

Similarly, at the 2018 Pyeongchang Winter Olympic Games, two Swiss skiers — and 199 staff — were reported to have contracted norovirus. This was particularly worrying as norovirus, like other enteric viruses, was highly contagious with an infection rate of 1.6 to 3.7. As outlined by Cherabuddi (2018), norovirus can rapidly make its way onto surfaces and food, although it originates from contaminated water sources. Coupled with the use of closed areas for communal dining (Cherabuddi, 2018), this facilitated rapid rates of norovirus infection, with infected persons similarly experiencing symptoms of intestinal inflammation and fever.

After two Swiss skiers fell ill with the highly contagious norovirus at the 2018 Pyeongchang Olympic Games, officials quickly stepped up venue disinfection efforts (South China Morning Post, 2018)

Overall, it is evident that enteric viruses bring significant inconvenience, as they not only prevent Olympic athletes from performing their best, but are also difficult to guard against. This reinforces the importance of regulating point sources in a holistic manner, from improving household access to sewage treatment systems, to developing tools to monitor and optimise these management efforts (Eisenberg, Bartram and Wade, 2016). Only then can health risks associated with water pollution be minimised, without requiring additional resources for viral testing that potentially detract attention from routine monitoring and create a vicious cycle of worsening water pollution.

References

Bosch, A., Pintó, R.M., Abad, F.X. (2006). Survival and Transport of Enteric Viruses in the Environment. In S.M. Goyal (Ed.), Viruses in Foods (pp. 151-187). Springer. https://doi.org/10.1007/0-387-29251-9_6 

Bosch, A., Guix, S., Sano, D., & Pinto, R. M. (2008). New tools for the study and direct surveillance of viral pathogens in water. Current Opinion in Biotechnology, 19(3), 295-301. https://doi.org/10.1016/j.copbio.2008.04.006 

Cherabuddi, K. (2018, February 20). Why is there a norovirus outbreak at the Winter Olympics? 4 questions answered. The Conversation. https://theconversation.com/why-is-there-a-norovirus-outbreak-at-the-winter-olympics-4-questions-answered-91886 

Eisenberg, J. N., Bartram, J., & Wade, T. J. (2016). The water quality in Rio highlights the global public health concern over untreated sewage. Environmental Health Perspectives, 124(10), 180-181. https://doi.org/10.1289/EHP662

Soligard, T., Steffen, K., Palmer, D., Alonso, J. M., Bahr, R., Lopes, A. D., … & Engebretsen, L. (2017). Sports injury and illness incidence in the Rio de Janeiro 2016 Olympic summer games: a prospective study of 11274 athletes from 207 countries. British Journal of Sports Medicine, 51(17), 1265-1271. https://doi.org/10.1136/bjsports-2017-097956 

South China Morning Post. (2018). Norovirus outbreak at Pyeongchang Winter Olympics has officials scrambling as local media frets [Online image]. South China Morning Post. https://www.scmp.com/sport/other-sport/article/2132404/norovirus-outbreak-pyeongchang-winter-olympics-has-officials 

Staggemeier, R., Heck, T. M., Demoliner, M., Ritzel, R. G., Röhnelt, N. M., Girardi, V., … & Spilki, F. R. (2017). Enteric viruses and adenovirus diversity in waters from 2016 Olympic venues. Science of the Total Environment, 586, 304-312. https://doi.org/10.1016/j.scitotenv.2017.01.223 

Weidner, T. G., & Sevier, T. L. (1996). Sport, exercise, and the common cold. Journal of athletic training, 31(2), 154-159. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1318446/pdf/jathtrain00018-0060.pdf

Posted on No Comments on Smoggy skies, foggier futures — The environmental injustice behind air pollution impacts (2)

Smoggy skies, foggier futures — The environmental injustice behind air pollution impacts (2)

Well-respected activist Martin Luther King Jr. had once remarked, “It really boils down to this: that all life is interrelated. We are all caught in an inescapable network of mutuality, tied into a single garment of destiny.” Perhaps the same can be said about air pollution at the Olympic Games — while its immediate impacts are confined to host cities, these impacts eventually snowball and transcend national boundaries. This interdependence between the local and global, then, is what explains the presence of environmental injustice globally. Similar to city-level environmental injustice where the marginalised are disproportionately affected by air pollution, developing countries are hit more severely by pollution-induced climate impacts.

Developing countries tend to bear the brunt of air pollution impacts, even though such pollution originates from mostly developed host cities (India Today, 2019)

But how exactly does localised air pollution extend to the global scale? The answer lies in the intensification of the greenhouse effect. When Olympic venues are constructed and urban traffic increases, massive amounts of radiation-trapping pollutants — particularly carbon dioxide — are emitted (Schmidt, 2020). This increase in global carbon footprint and trapping of longwave radiation not only raises global atmospheric temperatures, but also influences long-term rainfall availability (Kellogg and Schware, 2019). These climatic changes increase the likelihood of extreme weather events, which greatly devastate developing countries’ economies due to the lack of comprehensive mitigation measures (Kellogg and Schware, 2019).

While data on the exact climatic and socio-economic impact of Olympic-induced air pollution remains limited, it is fair to hypothesise that such pollution worsens environmental injustice. As mentioned previously, air pollution generated at the Olympic Games is inevitably significant, given the large scale of the event and its pollutive activities. In fact, according to Figure 1, new construction is one of the least sustainable but regularly occurring activities at the Olympic Games, with the second lowest sustainability score of 35. This, coupled with recurring incidents where extensive areas of carbon-absorbing vegetation are cut down for venue construction (Konstantaki and Wickens, 2010), reinforces the sheer amount of carbon being released throughout the Olympic Games. Therefore, it is possible that these localised carbon emissions accumulate, eventually altering global climate patterns while causing disproportionate economic damage to developing countries.

Figure 1: An infographic outlining the mean values of nine indicators used in assessing the sustainability of the Olympic Games, and the distribution of values. These indicators are scored from 0 to 100, with 0 meaning ‘least sustainable’ and 100 ‘most sustainable’ (Müller et al., 2021)

Therein lies the manifestation of environmental injustice, which is supported by Borunda’s (2019) findings on climate change-induced inequality. As per figure 2, most countries with high economic damage — who ironically generate the least carbon emissions — lie within the less developed Global South. Considering that these countries inherently suffer from climate vulnerability as they lack sufficient finances to invest in climate-resilient infrastructure, the occurrence of climatic impacts engenders the need for post-disaster relief and worsens their fiscal positions. This further compromises their climate vulnerability as they are unable to implement cost-intensive mitigation measures, creating a vicious cycle where these countries continually experience climate threats and environmental injustice.

Figure 2: A choropleth map illustrating the uneven impact of climate change on countries’ national economies (top) and the global distribution of carbon emissions per capita (bottom) (Borunda, 2019)

Admittedly, such environmental injustice can be lessened through supranational mutual aid programmes, where development agencies offer financial assistance to developing countries to tackle climate impacts. Nevertheless, such measures overlook the root cause of environmental injustice — the generation of pollution. Considering the potential for air pollutants to react with each other and develop into more hazardous secondary pollutants, it is hence crucial to minimise air pollution, especially at mega-events like the Olympic Games. Only then will we be one step closer to eradicating environmental injustice.

References

Borunda, A. (2019, April 23). Inequality is decreasing between countries—but climate change is slowing progress. National Geographic. https://www.nationalgeographic.com/environment/article/climate-change-economic-inequality-growing 

India Today. (2019). 1 lakh children under 5 years of age die from air pollution in India every year: Study [Online image]. India Today. https://www.indiatoday.in/education-today/latest-studies/story/air-pollution-india-deaths-children-five-years-report-centre-for-science-and-environment-1543779-2019-06-06  

Kellogg, W. W., & Schware, R. (Eds.). (2019). Climate change and society: consequences of increasing atmospheric carbon dioxide. Routledge. https://doi.org/10.4324/9780429048739 

Konstantaki, M., & Wickens, E. (2010). Residents’ perceptions of environmental and security issues at the 2012 London Olympic Games. Journal of Sport & Tourism, 15(4), 337-357. https://doi.org/10.1080/14775085.2010.533921 

Müller, M., Wolfe, S. D., Gaffney, C., Gogishvili, D., Hug, M., & Leick, A. (2021). An evaluation of the sustainability of the Olympic Games. Nature sustainability, 4(4), 340-348. https://doi.org/10.1038/s41893-021-00696-5 

Schmidt, R. (2020). The carbon footprint of the games–International climate change law and the Olympics. American Journal of International Law, 114, 362-367. https://doi.org/10.1017/aju.2020.71

Posted on No Comments on Smoggy skies, foggier futures — The environmental injustice behind air pollution impacts (1)

Smoggy skies, foggier futures — The environmental injustice behind air pollution impacts (1)

To many of us, there is nothing more gratifying than watching our favourite athletes push their limits and fight for victory at the Olympic Games. After all, it is these magical moments that encapsulate what the Olympic Games is symbolic of — glory, national pride and resilience. Yet, it is also in these very moments of celebration that we forget about those who are negatively and disproportionately impacted by the Olympic Games. This is especially so for air pollution, where we frequently overlook how residents of host cities — especially the marginalised — are widely exposed to pollutants, causing long-term health and socio-economic problems. 

Therein lies the issue of environmental injustice, where disadvantaged societal groups are forced to bear the “external costs of [economic] development” (Jerrett, 2009, p. 231). Such environmental injustice inherent to Olympic air pollution is most prominent at the city level, where socioeconomically vulnerable poor and minority communities inevitably face air pollution. Such exposure not only manifests from the construction of Olympic venues near marginalised communities, who lack the bargaining power to protest (Pulido, 2017), but also these communities’ reliance on public transport that increases their exposure to traffic emissions (Pratt et al., 2015). 

Tokyo residents in protest against the 2020 Olympic Games, which they argue will worsen environmental inequalities for the city’s poor (Burack, 2021)

However, you might still be wondering why environmental injustice poses a big problem for marginalised residents of host cities, apart from making them more susceptible to chronic respiratory illnesses. Well, it is precisely this likelihood of falling ill that engenders further socio-economic issues, namely the sustained lack of network capital and concomitant worsening of marginalisation. When residents are unwell, this not only compromises their work productivity, but also their ability to seek employment opportunities. This deprives them of network capital, which Urry (2012, p. 27) defines as the “capacity to engender and sustain relations… which generate practical benefit”, causing residents to be unable to earn livelihoods. More worryingly, however, this establishes a positive feedback loop where impoverished residents slip deeper into marginalisation, making them increasingly vulnerable to discriminatory pollutive practices (Pulido, 2017).

Such phenomena have begun emerging in Los Angeles, which is currently preparing for the 2028 Olympic Games. On the surface, Los Angeles is the epitome of a model host city, being equipped with sufficient finances to construct grand stadiums while pledging to improve minority access to sports spaces. However, this regard for inclusivity does not prove true in reality, as marginalised communities are forced to deal with the air pollution being generated during construction. Since 2016, construction has commenced for three major sports facilities (Mahoney, 2021), with such construction taking place in the predominantly Black city of Inglewood. This has not only heightened the risk of Inglewood residents developing respiratory illnesses, with these residents facing more air pollution than 96% of California state (Mahoney, 2021), but also raised concerns of long-term pollutant exposure from increased traffic (Henry, 2019). The latter is especially ironic — while low-income Inglewood residents use public transport to travel to work, it is also this dependence on public transport that makes residents sick and threatens their sustenance of livelihoods.      

The construction of SoFi Stadium in the black-dominated city of Inglewood has drawn criticism from residents, who experience significant air and noise pollution (Mahoney, 2021)

Hence, it is salient to recognise that while the Olympic Games might be a temporary highlight for host cities, its impacts can be permanent and far-reaching in scale. With that, stay tuned for the next post, which will investigate the environmental injustice of Olympic air pollution at the global scale!

References

Burack, E. (2021). The Olympics Devastate Host Cities and Need a Permanent Location [Online image]. Teen Vogue. https://www.teenvogue.com/story/olympics-host-cities-tokyo-los-angeles  

Henry, J. (2019, December 27). Traffic, noise from new LA Clippers arena would be ‘significant’ and ‘unavoidable,’ report says. Daily Breeze. https://www.dailybreeze.com/2019/12/27/traffic-noise-from-new-la-clippers-arena-would-be-significant-and-unavoidable-report-says/ 

Jerrett, M. (2009). Global geographies of injustice in traffic-related air pollution exposure. Epidemiology, 20(2), 231-233. https://doi.org/10.1097/ede.0b013e31819776a1 

Liu, L. (2013). Geographic approaches to resolving environmental problems in search of the path to sustainability: The case of polluting plant relocation in China. Applied Geography, 45, 138-146. https://doi.org/10.1016/j.apgeog.2013.08.011 

Mahoney, A. (2021, October 12). The environmental justice fight to block the 2028 Olympics in Los Angeles. Grist. https://grist.org/cities/2028-olympics-los-angeles-environmental-justice-inglewood/ 

Pratt, G. C., Vadali, M. L., Kvale, D. L., & Ellickson, K. M. (2015). Traffic, air pollution, minority and socio-economic status: addressing inequities in exposure and risk. International journal of environmental research and public health, 12(5), 5355-5372. https://doi.org/10.3390/ijerph120505355 

Pulido, L. (2017). Rethinking environmental racism: White privilege and urban development in Southern California. In K. Anderson and B. Braun (Eds.), Environment (pp. 379-407). Routledge. https://doi.org/10.4324/9781315256351-17 

Urry, J. (2012). Social networks, mobile lives and social inequalities. Journal of transport geography, 21, 24-30. https://doi.org/10.1016/j.jtrangeo.2011.10.003 

Posted on No Comments on But we’re only human: Heroic Olympians no exception to air pollution health effects (2)

But we’re only human: Heroic Olympians no exception to air pollution health effects (2)

Previously, we explored the potential effects of air pollution on Olympic athletes’ respiratory health through studying two key pollutants: ozone and particulate matter. While we might now know the health risks that these athletes face, this then begets the question of whether they can be trained to adapt to these risks and maintain their sporting standards.

Achieving this is possible, at least in theory. As argued by Mullins (2018), athletes with recent exposure to high ozone levels experience the acclimatisation effect, where they develop weaker respiratory complications in high-ozone environments. This corresponds with Sandford, Stellingwerff and Koehle’s (2020) findings that endurance runners from high-ozone environments display more consistent performance as they have become desensitised to irritant exposure. Such phenomena thus suggest that to minimise respiratory irritation and optimise performance, athletes can engage in short ozone adaptation training sessions to pre-acclimatise themselves. While this is inapplicable to particulate matter as there is no identifiable threshold below which respiratory illnesses do not develop, particulate matter exposure is harmless unless it exceeds the guideline value of 15 micrograms per cubic metre (World Health Organisation, 2021).

Figure 1: An infographic outlining how Olympic athletes should train for competitions in high-ozone environments (Sandford, Stellingwerff and Koehle, 2020)

Nevertheless, such adaptation strategies have proven ineffective as they jeopardise the health of high-risk athletes, specifically those with asthma. As reported by Burns et al. (2015), asthma is a chronic respiratory disorder that affects approximately 10% of athletes, and mostly those in endurance sports due to vigorous respiratory activity. It is precisely this correlation between sports intensity and asthma occurrence that explains why — despite the well-established nature of asthma treatment methods — pollution adaptation is not a foolproof solution. While adaptation training sessions admittedly require lower sports intensity than actual competitions in consideration of athlete safety exposure (Sandford, Stellingwerff and Koehle, 2020), they also involve longer training periods to facilitate the stabilisation of inflammatory symptoms. This is highly unsafe for asthmatic endurance athletes, as prolonged exposure to pollutants — even in small amounts — can exacerbate exercise-induced bronchospasms (Braniš and Vetvicka, 2010) and strain the lungs. Consequently, this increases the severity of asthma attacks, making it difficult for athletes to train and eventually compete properly.   

In fact, these concerns turned into reality during the 1984 Los Angeles Olympic Games, when top British track athlete Steve Ovett collapsed from pollution-induced asthma during the 800 metre finals. Despite Ovett’s ozone exposure in Britain, where heavy coal use for industrial activity sparked record-high ozone levels (National Atmospheric Emission Inventory, 2010), the pre-acclimatisation effect was not observed as the severe buildup of smog in Los Angeles (Elsom, 2016) significantly increased aerobic demand. This, coupled with the high level of sports intensity required for short-distance sprinting, resulted in severe bronchospasms that triggered Ovett’s asthma.    

British elite runner Steve Ovett (first from left) competing at the 1984 Los Angeles Olympic Games, moments before he collapsed from a pollution-induced asthma attack (Walters, 2012)

While Ovett eventually recovered and went on to compete at other mega sports events, many Olympic athletes remain fearful of pollution-induced health hazards, with some nearly dropping out of the Olympic Games. This reinforces the critical need for host cities to manage air pollution during the Olympic Games, so that athletes can compete without fear of health complications and even break Olympic records. After all, as Elsom (2016) warns, athletes cannot perform their best under polluted conditions, no matter how comprehensive their adaptation strategies are.

References

Braniš, M., & Vetvicka, J. (2010). PM10, ambient temperature and relative humidity during the XXIX Summer Olympic Games in Beijing: were the athletes at risk?. Aerosol and Air Quality Research, 10(2), 102-110. https://doi.org/10.4209/aaqr.2009.09.0055   

Burns, J., Mason, C., Mueller, N., Ohlander, J., Zock, J. P., Drobnic, F., … & European Community Respiratory Health Survey. (2015). Asthma prevalence in Olympic summer athletes and the general population: an analysis of three European countries. Respiratory Medicine, 109(7), 813-820. https://doi.org/10.1016/j.rmed.2015.05.002 

Elsom, D. (2016, August). Los Angeles 1984: The Olympics under a cloud. Geographical. https://geographical.co.uk/places/cities/item/1855-los-angeles-1984-the-olympics-under-a-cloud 

Mullins, J. T. (2018). Ambient air pollution and human performance: Contemporaneous and acclimatization effects of ozone exposure on athletic performance. Health economics, 27(8), 1189-1200. https://doi.org/10.1002/hec.3667 

National Atmospheric Emission Inventory. (2010). UK Emissions of Air Pollutants 1970 to 2008. https://uk-air.defra.gov.uk/assets/documents/reports/cat07/1009030925_2008_Report_final270805.pdf 

Sandford, G. N., Stellingwerff, T., & Koehle, M. S. (2020). Ozone pollution: a ‘hidden’ environmental layer for athletes preparing for the Tokyo 2020 Olympic & Paralympics. British Journal of Sports Medicine, 55(4), 189-190. https://doi.org/10.1136/bjsports-2020-103360  

Walters, M. (2012, June 7). Coe v Ovett: A battle of Britain fought out behind the Iron Curtain. [Online image]. Mirror. https://www.mirror.co.uk/sport/other-sports/athletics/london-2012-looking-back-at-coe-865439 

World Health Organisation. (2021, September 22). Ambient (outdoor) air pollution. https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health

Posted on No Comments on But we’re only human: Heroic Olympians no exception to air pollution health effects (1)

But we’re only human: Heroic Olympians no exception to air pollution health effects (1)

Picture this: you are the school’s cross-country representative, running around the track in preparation for the upcoming inter-school championships. You typically enjoy running; it leaves your senses feeling refreshed. Yet you find yourself dreading today’s run. Acrid smoke fills the air, with every breath feeling like a punch to the airways. Dust and fine particles enter your eyes, clouding up your vision. You want to speed up, but your suffocating lungs are crying out for rest. Running has never felt so difficult.

The above scenario may seem far-fetched, but it depicts the reality of many Olympic athletes who struggle to perform amidst polluted conditions in host cities. As you might recall, city-level air pollution is caused by high levels of road traffic stemming from short-term surges in tourist numbers (Gruben, Moss and Moss, 2012). Specifically, ozone and particulate matter are mainly emitted, altering the chemical composition of surrounding air which not only causes atmospheric change, but also worsens air quality. It is precisely the latter that poses health risks to athletes, hence inhibiting their potential to break Olympic records.

Athletes face risks of breathing problems and worsened performance when competing in polluted host cities (Owton, 2015).

While mostly studied for its radiation-trapping abilities, ozone remains notorious for causing respiratory irritation. The United States Environmental Protection Agency (EPA, 2021a) has found that ozone inhalation results in the constriction of airway muscles, subsequently inflaming the airways and causing breathing difficulties. Similarly, Lippi, Guidi and Maffulli (2008) report that ozone intake reduces expiratory volume, leading to constrained exhalation and wheezing. The most alarming discovery, however, is that these effects are strongest in the afternoon when endurance sports competitions are mostly held, thus putting athletes at risk. As ozone is formed when nitrogen oxides and hydrocarbons react under ultraviolet radiation, ozone levels peak at midday when ultraviolet radiation levels are highest (Sandford, Stellingwerff and Koehle, 2020). This increases the severity of respiratory symptoms, thus making it difficult for endurance athletes to perform as endurance sports require high aerobic demand.

Endurance sports athletes are particularly susceptible to respiratory irritation, given their high exposure to ozone at midday when competitions are held (Woodward, 2021)

Similarly, particulate matter — which refers to inhalable solid particles suspended in the air (EPA, 2021b) — can impair respiratory functions and athletes’ long-term physical abilities if overly inhaled. Particulate matter combines with sulfur dioxide and water vapour, which are gases also emitted by fuel-consuming vehicles, forming acid-coated particles that deposit in athletes’ lungs and cause irritation (Lippi, Guidi and Maffulli, 2008). Under prolonged inhalation, such inflammation can extend to other nerve tissues (Van Hee, 2012), eventually threatening athletes’ coordination and agility. 

Given the sheer potency of these pollutants, it is thus unsurprising that even elite athletes have fallen victim to air pollution-induced health effects. The next post will explore the ineffectiveness of pollution adaptation measures and case studies of athletes whose performance has been hindered due to respiratory complications, so stay tuned!

References

Gruben, K. H., Moss, S. E., & Moss, J. (2012). Do the Olympics create sustained increases in international tourism?. Journal of International Business Research, 11(1), 135-150. 

Lippi, G., Guidi, G. C., & Maffulli, N. (2008). Air pollution and sports performance in Beijing. International journal of sports medicine, 29(8), 696-698. https://doi.org/10.1055/s-2008-1038684 

Owton, H. (2015, September 8). Polluted host cities are putting our champion athletes at risk [Online image]. The Conversation. https://theconversation.com/polluted-host-cities-are-putting-our-champion-athletes-at-risk-46830 

Sandford, G. N., Stellingwerff, T., & Koehle, M. S. (2020). Ozone pollution: a ‘hidden’ environmental layer for athletes preparing for the Tokyo 2020 Olympic & Paralympics. British Journal of Sports Medicine, 55(4), 189-190. https://doi.org/10.1136/bjsports-2020-103360  

United States Environmental Protection Agency (2021, May 5). Health Effects of Ozone Pollution. https://www.epa.gov/ground-level-ozone-pollution/health-effects-ozone-pollution#:~:text=Ozone%20can%20cause%20the%20muscles,and%20sore%20or%20scratchy%20throat 

United States Environmental Protection Agency (2021, May 26). Particulate Matter (PM) Basics. https://www.epa.gov/pm-pollution/particulate-matter-pm-basics#:~:text=PM%20stands%20for%20particulate%20matter,seen%20with%20the%20naked%20eye 

Van Hee, V. C. (2012). From Olympians to mere mortals: the indiscriminate, global challenges of air pollution. American journal of respiratory and critical care medicine, 186(11), 1076-1077. https://doi.org/10.1164/rccm.201209-1594ED 

Woodward, A. (2021, August 12). Runners wearing Nike ‘super shoes’ dominated in the Olympics, taking more than 60% of podium spots [Online image]. Business Insider. https://www.businessinsider.com/nike-runners-trounce-olympics-competitors-super-spike-shoe-technology-2021-8