Can strategies mitigating harmful algal blooms (HABs) be implemented everywhere?

In our previous post, we explored the effectiveness of HAB mitigation strategies adopted during the 2008 Beijing Olympic Games. Specifically, we identified the strategies’ lack of focus on anthropogenic water pollution to be problematic, and proposed that Qingdao officials should tighten waste disposal regulations while investing in specialised wastewater treatment.  

While these strategies appear foolproof in principle, they may not be effectively implemented in reality. This is especially so across space, where political and socioeconomic contexts vary and influence countries’ abilities to implement these strategies. Firstly, ramping up investments in advanced treatment technologies can be extremely costly, making it a financially unfeasible option in less affluent countries. Modern treatment systems that adopt high-tech processes such as the removal of residual contaminants (specialised treatment) can cost billions of dollars, notwithstanding additional costs of building pipes connecting these systems to areas with pollutive activity (Hill, 2012). Hence, such investments can be a financial burden for developing countries, potentially offsetting the economic returns from Olympic-induced tourism.

Wastewater treatment technologies that focus on specialised treatment are costly for developing countries, influencing their ability to adopt them when managing HAB growth (Wilo, n.d.)

In Qingdao, for example, nearly $100 million was spent on algae clean up at the 2008 Beijing Olympic Games (Glibert, 2014), on top of its hefty $17.5 billion Olympic budget (Mol, 2010). $100 million in losses was also incurred by Qingdao’s stronghold abalone and sea cucumber industries (Glibert, 2014), which saw record low yields. Therefore, investing in specialised treatment technologies was only likely to threaten Qingdao’s financial position, as Chinese cities did not receive central government funding. Although such investments could arguably reduce algae clearance costs in the long-term, the massive short-term outflow of capital would be too much to handle, potentially requiring countries to obtain loans from supranational organisations. This reinforces the financial unfeasibility of implementing advanced treatment technologies in developing countries.

Secondly, although regulating agricultural-related point sources can help to nip anthropogenic water pollution in the bud, countries might not have the political will to do so. In countries that heavily rely on the agricultural industry for economic growth, the amount of chemical waste produced is positively correlated to the industry’s growth. As such, managing waste disposal is challenging as it would inevitably involve the capping of farming operations and amount of profits earned. In 2011, the sudden accumulation of Ulva algae in the French province of Brittany coincided with the rapid expansion of livestock farming (Smetacek and Zingone, 2013). As the meat industry was integral to Brittany’s economy, local officials argued that HAB formation was inevitable as nutrients were continually released via animal manure (Smetacek and Zingone, 2013). In fact, eutrophication rates surpassed those of manure treatment, meaning that regulating these rates would either involve reducing livestock numbers — an economically unfeasible option — or investing in treatment technology. This illustrates the conflict between economy and environment, where countries might be unwilling to regulate waste disposal for fear of jeopardising growth. Furthermore, the regulation of agricultural practices, as with all policies, takes years to implement (Smetacek and Zingone, 2013). Hence, whether policymakers can maintain political will remains uncertain, amidst more pressing objectives of increasing economic influence through mega-events like the Olympic Games.

Developing countries might not have the political will to regulate waste disposal, as doing so has adverse effects on agricultural growth (Damara Bali Foundation, 2019)

So, does this suggest that HAB formation is a problem that cannot be solved? Certainly not! However, acknowledging the economic obstacles that stand in developing countries’ paths can facilitate the conceptualisation and implementation of context-specific HAB mitigation strategies. More importantly, officials should seek to understand the growth dynamics of various algae species, as only then can they manage HABs in a cost-effective manner.

References

Damara Bali Foundation. (2019). 25 farmers have been trained in compost making made of animal manure & agricultural waste [Online image]. Damara Bali Foundation. https://www.damara-bali.org/25-farmers-have-been-trained-in-compost-making-made-of-animal-manure-agricultural-waste/ 

Glibert, P. M. (2014). Harmful Algal Blooms in Asia: an insidious and escalating water pollution phenomenon with effects on ecological and human health. ASIANetwork Exchange, 21(1), 1-17. https://doi.org/10.16995/ane.46  

Hill, M. K. (2012). Water Pollution. In M. K. Hill (Ed.), Understanding Environmental Pollution (pp. 236-285). Cambridge University Press. https://doi.org/10.1017/cbo9780511840654 

Mol, A. P. (2010). Sustainability as global attractor: The greening of the 2008 Beijing Olympics. Global Networks, 10(4), 510-528. https://doi.org/10.1111/j.1471-0374.2010.00289.x 

Smetacek, V., & Zingone, A. (2013). Green and golden seaweed tides on the rise. Nature, 504(7478), 84-88. https://doi.org/10.1038/nature12860 

Wilo. (n.d.). Clean water for Qingdao [Online image]. Wilo. https://wilo.com/tw/en/Solutions-Provider/Global-references/Clean-water-for-Qingdao/ 

Blooming algae problem caused by water pollution stirs trouble for Olympic teams (2)

How often does one spot a floating carpet of algae at the Olympic Games? That was a question that Qingdao government officials had, when the city’s Olympic sailing venues were struck by unprecedented HAB formation in 2008 — the first such event in the Olympic Games’s 112-year history. The rapid spreading of algal bloom not only posed threats to aquatic species by releasing toxic hydrogen sulphide during decomposition (Glibert, 2014), but also disrupted sailing training and test events. As such, this warranted the implementation of large-scale mitigation strategies, which unfortunately proved ineffective as they overlooked the root cause of HAB growth — anthropogenic water pollution. 

The strategies adopted by Qingdao officials were primarily focused on clearing existing traces of algal bloom, given their priority to reduce event disruptions and maintain their image as a competent host city. As reported by Hu and He (2008), the immediate measure taken was to dispatch manpower to dredge the waters, with nearly 10000 locals and 1000 vessels being roped in. Following this massive clean-up exercise, where over 700000 tons of algae were collected (Hu and He, 2008) and $100 million of losses was incurred (Glibert, 2014), officials deployed containment booms to protect sailing areas against HAB infestation. Approximately 24 kilometres of containment booms, which refer to floating barriers typically used to contain oil spills, were used (Hu and He, 2008).  

 

Massive numbers of vessels — and even bulldozers — were deployed to dredge the algae-infested waters in Qingdao’s sailing venues (Cohen, 2008)

However, these measures turned out ineffective, with traces of algal bloom reemerging shortly after affected areas had been weeded (Cohen, 2008). While clean-up and containment strategies were admittedly necessary as HAB growth was disrupting the running of the Olympic Games, they failed to address the central role of water pollution in facilitating such growth. As mentioned previously, HABs develop when surplus nitrate and phosphorus from fertilisers or organic waste lead to nutrient excesses crucial for HAB formation (Hill, 2012). This shows that HAB formation in Qingdao was not the result of algae invasion from offshore areas as officials had suggested (Leliaert et al., 2008), but rather, the localised dumping of waste. These findings are supported by Leliaert et al. (2008), who argue that HABs in Qingdao were triggered by eutrophication — the process where water bodies continually receive nutrient input and eventually disappear (Hill, 2012).

Hence, it was unsurprising that officials’ mitigation strategies failed as point sources were not regulated, resulting in high HAB growth rates of 21.9% daily (Smetacek and Zingone, 2013). Specifically, officials could have advised farmers against dumping chemical waste into tributaries (Smetacek and Zingone, 2013) while investing in wastewater treatment infrastructure. By undertaking specialised treatment (Figure 1), where excess nitrate and phosphorus are thoroughly filtered out (they are only partially removed during primary treatment), eutrophication could have been prevented alongside HAB growth. Manpower could also have been significantly cut back on, bringing major cost savings for officials while making the 2008 Beijing Olympic Games a more financially sustainable one. 

Figure 1: Wastewater treatment process (Hill, 2012)

References

Cohen, C. (2008, July 3). China’s blooming algae problem that’s swamping the Olympics. Daily Mail. https://www.dailymail.co.uk/news/article-1031444/Chinas-blooming-algae-problem-thats-swamping-Olympics.html 

Glibert, P. M. (2014). Harmful Algal Blooms in Asia: an insidious and escalating water pollution phenomenon with effects on ecological and human health. ASIANetwork Exchange, 21(1), 1-17. https://doi.org/10.16995/ane.46  

Hill, M. K. (2012). Water Pollution. In M. K. Hill (Ed.), Understanding Environmental Pollution (pp. 236-285). Cambridge University Press. https://doi.org/10.1017/cbo9780511840654 

Hu, C., & He, M. X. (2008). Origin and offshore extent of floating algae in Olympic sailing area. Eos, Transactions American Geophysical Union, 89(33), 302-303. https://doi.org/10.1029/2008eo330002 

Leliaert, F., Malta, E. J., Engelen, A. H., Mineur, F., & De Clerck, O. (2008). Quindao algal bloom culprit identified. Marine Pollution Bulletin, 56(9), 1516-1516. https://doi.org/10.1016/j.marpolbul.2008.08.004 

Smetacek, V., & Zingone, A. (2013). Green and golden seaweed tides on the rise. Nature, 504(7478), 84-88. https://doi.org/10.1038/nature12860

Blooming algae problem caused by water pollution stirs trouble for Olympic teams (1)

Water pollution need not take its form in unsightly swathes of untreated waste. Sometimes, it can manifest in harmful algal blooms (HABs), whose cheery green hues belie their toxic and troublesome nature.  

Normally, algae is harmless, and is integral to the aquatic ecosystem as it forms the base of the food chain (Glibert, 2014). Yet, it can threaten aquatic species’ lifespans and human health when accumulated in large amounts (Fistarol et al., 2015). In the presence of untreated waste, such as organic matter or unused fertilisers containing reactive nitrogen and phosphorus (Hill, 2012), nutrients are abundant and absorbed by algae. This facilitates large-scale HAB formation, producing toxins that not only accumulate in seafood but also cause water contamination (Fistarol et al., 2015). HABs are hence considered to be water pollutants, as they alter water quality and spread at unmanageable rates characteristic of transboundary water pollution (Hill, 2012).

HABs are notorious for killing aquatic species and causing harm to human health by contaminating seafood (Davies, 2015)

Recently, HABs have entered the spotlight — not for causing fish kills and disrupting the global aquaculture industry (Glibert, 2014), but rather, the Olympic Games. Most notably, HABs of the Enteromorpha prolifera species were spotted at sailing venues in Qingdao (Glibert, 2014) leading up to the 2008 Beijing Olympic Games. This was attributed to the widespread dumping of nitrogen-containing farming chemicals into inland lakes that eventually flowed into Qingdao’s Yellow Sea (Branigan, 2008), where sailing venues were located. Such HAB formation was not only problematic as the island-city’s famed pristine blue waters were stained a bright green, but also because the blanket of algae hindered sailboats’ movements. As reported by Glibert (2014), the scale of HAB growth amounted to a sizable 1900 square kilometres, with nearly one-third of the competition area being covered in algal bloom. This caused blockage to practice routes while preventing Olympic athletes from sailing through the waters smoothly, thus compromising the efficacy of their training. As British windsurfer Bryony Shaw had then cautioned, “If [the algae] is still here in August [when we compete], it could be a real problem.”

Sailing venues in the Eastern Chinese city of Qingdao were plagued by HAB growth prior to the 2008 Beijing Olympic Games, hampering Olympic sailors’ training (Barlow, 2008)

Although the thick algal mass was eventually cleared and Olympic sailing events could proceed as planned, questions remained as to whether HAB formation could be more effectively mitigated. This was particularly of interest to aspiring host cities with tropical climates, as the fertilising effect of nitrogen and phosphorus was reportedly higher in warm regions (Marris, 2008). The following posts will hence evaluate the mitigation strategies adopted during the 2008 Beijing Olympic Games and whether they can be replicated elsewhere, so stay tuned!

References

Barlow, K. (2008). Algae swamps Olympic sailing city [Online image]. ABC News. https://www.abc.net.au/news/2008-06-28/algae-outbreak-hampers-olympic-sailing-preparations/2487806  

Branigan, T. (2008, June 30). Chinese race to clear algae from Olympic sailing venue. The Guardian. https://www.theguardian.com/environment/2008/jun/30/pollution.olympicgames2008 

Davies, W. (2015). Tonnes of dead fish removed from Rio Olympic rowing venue [Online image]. BBC. https://www.bbc.com/news/world-latin-america-32345508 

Fistarol, G. O., Coutinho, F. H., Moreira, A. P. B., Venas, T., Cánovas, A., de Paula Jr, S. E., … & Thompson, F. L. (2015). Environmental and sanitary conditions of Guanabara Bay, Rio de Janeiro. Frontiers in microbiology, 6, 1232. https://doi.org/10.3389/fmicb.2015.01232 

Glibert, P. M. (2014). Harmful Algal Blooms in Asia: an insidious and escalating water pollution phenomenon with effects on ecological and human health. ASIANetwork Exchange, 21(1), 1-17. https://doi.org/10.16995/ane.46 

Hill, M. K. (2012). Water Pollution. In M. K. Hill (Ed.), Understanding Environmental Pollution (pp. 236-285). Cambridge University Press. https://doi.org/10.1017/cbo9780511840654 

Marris, E. (2008). Scientists identify algae that almost swamped the Olympics. Nature. https://www.nature.com/articles/news.2008.998 

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

In deep water — The making of a water pollution crisis at the 2016 Rio Olympic Games (2)

In our previous post, we explored the anthropogenic causes of water pollution at the 2016 Rio Olympic Games and highlighted the pressing need to control these point sources. In this post, however, we will analyse Rio de Janeiro’s water pollution crisis using a different lens — residence time. Through investigating the persistence of pollutants in Rio de Janeiro’s Guanabara Bay, we can gain insight on the physical factors that contributed to the crisis. 

You might recall from our second post that residence time refers to the duration that pollutants stay in a medium before being removed. Indeed, in the context of water pollution, residence time is calculated by dividing the amount of pollutant in the water body by the inflow or outflow rate of the pollutant. This means that we not only have to consider the total amount of pollutants, but also the duration needed to flush out pollutants by renewing water bodies.

We can thus deduce that pollutants found in Rio de Janeiro’s untreated waste have a long residence time, as waste is continuously accumulated in water bodies while water renewal rates remain low. As outlined by Fistarol et al. (2015), it takes approximately 11 days to renew 50% of water in Guanabara Bay, meaning that it requires at least 22 days for pollutants to be completely flushed out. While this residence time appears short considering that a massive 25 cubic metres of waste is discharged every second (Cotovicz Jr et al., 2016), it remains problematic as pollutants cannot be removed in time for consecutively-held Olympic water sports events. This is especially so for sailing and open-water swimming events, which often take place in Guanabara Bay and require athletes to cover long distances in the water (Keith, 2016). Furthermore, water renewal rates vary across Guanabara Bay, with these rates being the lowest in inner regions where tidal circulation is low (Fistarol et al., 2015). This suggests that pollutant residence time is particularly long in these regions, as pollutants are seldom flushed out.

Given long residence time of pollutants at Guanabara Bay, Olympic sailors and open-water swimmers are highly susceptible to gastrointestinal illnesses (Wharton, 2014)

In analysing residence time, it is also crucial to consider the breakdown of pollutants, as different pollutants have different residence times. One of the most persistent pollutants in Guanabara Bay is methane, which is released from untreated sewage and degrades water quality by causing acidification (Cotovicz Jr et al., 2016). According to Junge (1974), methane has a residence time of 4 years, suggesting that even after pollutants are flushed out through water renewal every 22 days, traces of methane still exist. This is supported by Cotovicz Jr et al. (2016)’s findings that methane concentrations in central Guanabara Bay are perpetually high, not only because of low tidal circulation but also the degasification of dissolved methane into the atmosphere. Thus, this reinforces that pollutant types also influence the severity of Rio’s water pollution crisis, as they affect residence time and the extent of water quality degradation.

The release of long-lasting pollutants from untreated waste, such as methane, has exacerbated water pollution in Rio de Janeiro (Davis and Manfred, 2015)

In hindsight, while Rio’s water pollution crisis stemmed from poor waste management policy, it was made worse by long pollutant residence times. While there is little that water governing bodies can do to reduce pollutant residence times, which depend on uncontrollable factors like tidal circulation, this awareness can hopefully galvanise them into ramping up waste management efforts. Only then can the extent of long-term waste accumulation be minimised, and Olympic athletes safely compete in the waters. 

References

Cotovicz Jr, L. C., Knoppers, B. A., Brandini, N., Poirier, D., Costa Santos, S. J., & Abril, G. (2016). Spatio‐temporal variability of methane (CH4) concentrations and diffusive fluxes from a tropical coastal embayment surrounded by a large urban area (Guanabara Bay, Rio de Janeiro, Brazil). Limnology and Oceanography, 61(S1), S238-S252. https://doi.org/10.1002/lno.10298 

Davis, S. & Manfred, T. (2015). A 2016 Rio Olympics waterway has levels of viruses akin to raw sewage — here’s what it looks like [Online image]. Business Insider.  https://www.businessinsider.com/rio-olympics-water-pollution-sewage-photos-2015-7 

Fistarol, G. O., Coutinho, F. H., Moreira, A. P. B., Venas, T., Cánovas, A., de Paula Jr, S. E., … & Thompson, F. L. (2015). Environmental and sanitary conditions of Guanabara Bay, Rio de Janeiro. Frontiers in microbiology, 6, 1232. https://doi.org/10.3389/fmicb.2015.01232 

Junge, C. E. (1974). Residence time and variability of tropospheric trace gases. Tellus, 26(4), 477-488. https://doi.org/10.1111/j.2153-3490.1974.tb01625.x 

Keith, E. F. (2016). Treating Rio’s Wastewater Beyond the Olympics. Natural Resources & Environment, 31(4), 48-50. http://www.jstor.org/stable/44213918 

Wharton, D. (2014). Sailors test polluted waters at 2016 Rio de Janeiro Olympic site [Online image]. Los Angeles Times. https://www.latimes.com/sports/sportsnow/la-sp-sn-sailors-2016-rio-de-janeiro-olympics-20140811-story.html

 

In deep water — The making of a water pollution crisis at the 2016 Rio Olympic Games

2 October 2009 signified a turning point for Rio de Janeiro’s environmental scene. Following decades of grappling with ill-managed waste disposal and severe water contamination (Trendafilova, Graham and Bemiller, 2017), the Brazilian city was declared as host of the 21st Olympic Games. This moment was historic not only because it marked an achievement once unthinkable, but also because it provided Rio de Janeiro the golden opportunity to clean its polluted waterways and improve its urban image.

Yet, these feelings of pride and optimism quickly dissolved into anger and disappointment, as targets of achieving 80% sewage treatment remained unmet. More alarmingly, Rio de Janeiro’s iconic Guanabara Bay remained nearly as polluted as before, making it less than ready to host upcoming Olympic water sports events. This raised a big question among the general public and international community: why was water pollution unresolved despite the increased construction of sewage systems? 

Just days before the Olympics, reports revealed that Rio’s Guanabara Bay remained clogged with untreated waste, raising health concerns amongst athletes (Biller and Smith, 2016)

The answer lay in the high rates of improper waste disposal, especially in favelas. As we might recall from the previous post, favelas mostly lack access to sewage facilities, resulting in domestic waste being discharged directly into adjacent water bodies. This lack of access does not only refer to the measly number of facilities, which officials have addressed by ramping up construction works in neighbourhoods surrounding Guanabara Bay (Keith, 2016), but also their poor proximity to favelas. As noted by Fistarol et al. (2015), favelas occupy large areas of non-inhabited forest land, making it challenging to identify centrally-accessible areas where facilities can be built. Furthermore, favelas are unevenly distributed around Rio de Janeiro (Figure 1), with some located in hilly areas above 50 metres in elevation. Therefore, favela dwellers who live far from sewage facilities have little choice but to dispose of their waste in smaller tributaries (Keith, 2016).

Figure 1: Distribution of favelas in Rio de Janeiro (O’Hare and Barke, 2002)

However, these tributaries often merge into larger channels connected to Guanabara Bay, which receives liquid effluents produced from 16 municipalities (Fistarol et al., 2015). This results in the significant accumulation of domestic waste in Guanabara Bay, which surpasses the rate of wastewater treatment. According to Figure 2, the number of secondary and tertiary channels flowing into Guanabara Bay far exceeds the number of wastewater treatment plants, with there only being two plants within Guanabara Bay’s drainage basin. It is hence unsurprising that water pollution has not abated despite the higher uptake of sewage treatment facilities, as waste disposal rates in favelas outpace that of treatment.

Figure 2: Map of tributaries connected to Guanabara Bay (Comitê de Bacia da Baía de Guanabara, 2013)

Ultimately, it is regrettable that state efforts to clean up Guanabara Bay — and Rio de Janeiro’s notorious reputation as “an open sewer” — have failed. Only 78% of households are connected to sewer systems (Keith, 2016), with this percentage not accounting for favelas, and water quality remains poor based on World Health Organisation guidelines. It is hence evident that water pollution is a complex issue, and can only be addressed when its point sources are accurately identified and controlled to prevent large-scale pollutant transport. Furthermore, in linking back to our second post on the complexity of collecting Olympic pollution data, we should recognise that data collection is not always an objective exercise, with marginalised groups often being excluded from the process.  

References

Biller, D. & Smith, M. (2016). Rio Promised to Clean Up Guanabara Bay Before the Olympics [Online image]. Bloomberg. https://www.bloomberg.com/features/2016-unsolved-murder-in-rio/ 

Comitê de Bacia da Baía de Guanabara. (2013). Location of Wastewater Treatment Plants around Guanabara Bay [Online image]. Comitê de Bacia da Baía de Guanabara. http://www.comitebaiadeguanabara.org.br/sig-rhbg/ 

Fistarol, G. O., Coutinho, F. H., Moreira, A. P. B., Venas, T., Cánovas, A., de Paula Jr, S. E., … & Thompson, F. L. (2015). Environmental and sanitary conditions of Guanabara Bay, Rio de Janeiro. Frontiers in microbiology, 6, 1232. https://doi.org/10.3389/fmicb.2015.01232 

Keith, E. F. (2016). Treating Rio’s Wastewater Beyond the Olympics. Natural Resources & Environment, 31(4), 48-50. http://www.jstor.org/stable/44213918 

O’Hare, G., & Barke, M. (2002). The favelas of Rio de Janeiro: A temporal and spatial analysis [Online image]. GeoJournal. https://doi.org/10.1023/A:1025134625932 

Trendafilova, S., Graham, J., & Bemiller, J. (2017). Sustainability and the olympics: the case of the 2016 Rio summer games. Journal of Sustainability Education, 16(3), 1-22. http://www.susted.com/wordpress/wp-content/uploads/2018/01/Trendafilova-Graham-Bemiller-JSE-Fall-2017-General-PDF.pdf

Swimming in sewage: How improper waste disposal has clouded the Olympic Games

Welcome back to Quit Playing Games (With Our Earth)! Earlier, we have discovered how air pollution is generated at the Olympic Games, resulting in profound health and socioeconomic impacts that play out across different geographical scales. In the next few posts, however, we will be exploring a different type of pollution — one that is arguably more visible, but equally far-reaching in effect.

That is none other than water pollution, which has emerged as a rising concern for Olympic water sports events in recent years. As defined by Owa (2013), water pollution arises when pollutant amounts are so large that the water is no longer suitable for specific uses, such as drinking and bathing. This has precisely been the case at several Olympic Games, with the most notorious example being the 2016 Rio Olympic Games where waters were found to contain viruses 1.7 million times more hazardous than that in America.

The issue of water pollution first came into the spotlight during the 2016 Olympic Games, when dangerous pollutant levels were detected in Rio’s waters (New York Times, 2015).

So, what leads to water pollution at the Olympic Games? While determining its exact cause is challenging as water pollution can be nonpoint source with “many possible points of origin” (Hill, 2012, p. 239), improper waste disposal remains a key contributor. This is especially so for domestic and industrial waste (Owa, 2013), which often go mismanaged as waste treatment infrastructure are unable to keep pace with rapid urban population growth and industrial expansion (Trendafilova, Graham and Bemiller, 2017). In Rio, for example, population growth has spiked alongside the number of slums or favelas without access to sewage systems, resulting in nearly half of Rio’s waste being dumped into the sea untreated (Vidal, 2016). Similarly, the lack of separate drainage systems for rainfall and sewage in Tokyo has led to the flushing of untreated sewage into Tokyo Bay during rainy seasons, so as to avoid overwhelming the central treatment system (Yokoyama, 2021).

The excessive presence of pollutants in Olympic swimming pools has led to an alarming phenomenon: these pools have turned a murky shade of green (Forbes, 2016)

Needless to say, such long-term dumping of waste into central water bodies has given rise to operational problems for host cities. Not only is water in Olympic pools and sailing venues murky as it is obtained from these water bodies, it also contains excessive viral loads that make it unsafe for athletes to compete. More significantly, the presence of these health hazards has led numerous athletes to pull out of events, concomitantly pushing host cities to undertake cleaning measures to assuage athletes’ fears while maintaining their image. On that note, the next post will investigate how unregulated anthropogenic activity and waste disposal led to disastrous water pollution at the 2016 Rio Olympic Games, so stay tuned!

References

Forbes. (2016). Why Are Rio’s Olympic Pools Green And Smelly? Ryan Lochte’s Hair Holds The Answer [Online image]. Forbes. https://www.forbes.com/sites/grrlscientist/2016/08/15/chemistry-its-why-the-rio2016-pool-water-is-green/?sh=39506b082d6c 

Hill, M. K. (2012). Water Pollution. In M. K. Hill (Ed.), Understanding Environmental Pollution (pp. 236-285). Cambridge University Press. https://doi.org/10.1017/cbo9780511840654 

New York Times. (2015). Filthy Rio de Janeiro Water a Threat at 2016 Olympics [Online image]. New York Times. https://www.nytimes.com/2015/07/31/sports/olympics/filthy-rio-de-janeiro-water-a-threat-at-2016-olympics.html 

Owa, F. D. (2013). Water pollution: sources, effects, control and management. Mediterranean journal of social sciences, 4(8), 65-68. https://doi.org/10.5901/mjss.2013.v4n8p65 

Trendafilova, S., Graham, J., & Bemiller, J. (2017). Sustainability and the olympics: the case of the 2016 Rio summer games. Journal of Sustainability Education, 16(3), 1-22. http://www.susted.com/wordpress/wp-content/uploads/2018/01/Trendafilova-Graham-Bemiller-JSE-Fall-2017-General-PDF.pdf 

Vidal, J. (2016, August 3). Why is Rio de Janeiro finding it so hard to clear up its waste? The Guardian. https://www.theguardian.com/global-development/2016/aug/03/why-is-rio-de-janeiro-finding-it-so-hard-to-clear-up-its-waste-olympic-games 

Yokoyama, E. (2021, July 14). Just Days Before Olympics, Tokyo’s Outdoor Swimming Venue Stinks. Bloomberg. https://www.bloomberg.com/news/articles/2021-07-13/two-weeks-before-tokyo-olympic-swimming-event-the-water-stinks