Is Water Truly a Life Source? A Look at Water Treatment Byproducts Effects on Health

A new docu-series streaming on Netflix called Down to Earth with Zac Efron explores new and old ways of living in our world. Through the series, Zac Efron and Darin Olien travel around the world to find lifestyles that include: clean energy in Iceland, communal living in Costa Rica, and longevity in Sardinia. One very interesting episode, in Paris, opens with Zac and friends having a tasting session…of water! Similar to a wine tasting, a sommelier led the group through sampling water from different sources. He explained the varying tastes, mineral content, nutrient values, and so on. Contrary to popular belief, water can be very complex much like a full-bodied wine. The sommelier explains to the group that the tap water in the United States is poor in quality.¹ How could this be? We clean our water, process it, even add in nutrients like fluoride that help protect people’s health. How could drinking water around the United States be bad? I decided to explore his claim in-depth to see what really is going on with the water here in Bloomington, Indiana. Where it led me was to the very beginning, the water treatment process.

In the episode, Zac Efron’s exploration turned to Paris, France, and its high-quality water available. The same water in homes is available for free to everyone through public fountains. He interviewed a leader of the Paris water treatment plant and learned about the process. Parisian water treatment undergoes a typical process of coagulation, sedimentation, filtration. But, then, it deviates from a majority of treatment processes.¹ Parisian water treatment utilizes UV light and hyper-oxygenation to clean the water of microorganisms and viruses.¹ Comparatively, most other municipal water treatment systems use chemicals for cleaning: specifically, chlorine and sometimes chloramines.

In American water treatment (and here in Bloomington) we follow the typical cleaning process. Since the process is not common knowledge, I will explain it further below.

 

After the process, water is either stored or sent directly to consumer homes for consumption. While this is not the only process for water treatment, it is by far the most popular. Most of the world utilizes these four steps and chemicals to clean the water for human consumption.

With this context, it’s easy to see that a majority of the process is benign. Removing large particulate matter like dirt, leaves, rocks, and so on does not require a lot of effort. It actually just uses natural materials to filter out these impurities. The only “active” cleaning process, in which water composition changes drastically, is chlorination. The disinfection process involves putting in small amounts of chlorine, to sterilize it for consumption. Excess chlorine will be removed so no greater than 4 mg/L or 4 parts per million (ppm) remain in drinking water.³ The regulation of residual chlorine protects the water from bacterial growth and humans from any toxins.³ However, like all chemicals, chlorine reacts with other organic matter to form disinfection byproducts.⁴ The newly formed chemicals have no impact on disinfecting the water; however, these byproducts may not be safe for human consumption. There are two major classes class called trihalomethanes (THM), which encompass four disinfection byproducts, and haloacetic acids (HAA).⁴ Both THMs and HAAs have substantial amounts of research looking at how they affect human and environmental health

As I began reading the literature on the two classes, I decided to focus my research on HAAs and THMs. Another major reason to look at these two was that both have components of data collection. Because previous research implicates them to be associated with negative health effects, water treatment facilities report on THMs and HAAs. Large dosage studies have shown that both HAAs and THMs to be carcinogenic in model organisms like rats.⁵ Specifically, THMs are linked to bladder cancer specifically and generally increased water toxicity.⁶ HAAs in concentrations between 2 and 5,000 µM impacted embryonic development resulting in problems in heart, facial, and neural development issues.⁷ However, it is important to note that concentrations in these studies are higher than regulated levels in the water. But, because research indicates possible damaging effects, our federal government has enforced regulations on HAA and THM levels in drinking water.⁸ Therefore, with the regulations, our exposure to chlorination byproducts in drinking water should be minimal.

Though model organisms like rats receive large dosages of THMs or HAAs, health findings should still be considered. Low dosages do not mean there will be no effects. It depends both on the size and length of exposure. Because water is a necessity for all organisms, it can be inferred that we are constantly being exposed to small dosages of both chemical classes. Long-term, small dosages do show links to adverse health effects in humans.⁶ The carcinogenic properties likely stem from long-term exposure rather than large dosages.⁶ In other words, bladder cancer comes from repeated exposure to THMs rather than consuming a high concentration. The long-term exposure data and its health implications are harder to study because of compounding factors. It is often difficult to separate the causative agent for cancers because many different chemicals, radiation, etc. have links to cancer. Therefore, THMs and HAAs impact our risk of cancer, increasing our chances. Exposure to them through our drinking water with our genetics and other exposures to carcinogens creates the perfect “cancer cocktail.”

After reading the literature, I wondered if Bloomington’s water meets the federal standards? The city of Bloomington publishes annual water quality reports online. I decided to look at these reports for data on THMs and HAAs to see if there were any interesting trends. The table and graph below depict the data from 2011 to 2020:

 

Regulatory standards for THMs set the limit to no more than 80 parts per billion (ppb) and for HAAs at no more than 60 ppb.⁹ Bloomington THM levels appear to remain well below the limit, with the exception of 2015. HAA levels normally stay between 45-59 ppb. It seems like HAAs are harder to limit and control compared to THMs. The levels of HAAs and THMs seem to fluctuate in a similar manner. What causes these fluctuations? Research suggests that levels of the chemicals can be seasonal, so data collection timing may have had a factor.¹⁰ Levels can also fluctuate due to the quality of the source water and its pH, organic matter prevalence, temperature, residual chlorine, etc.¹⁰ It is possible, during the years of increasing rates, source water quality was low due to increased/decreased rainfall, higher pH levels from other chemicals in the source water increased water temperatures, and so on. The best course of action to reduce fluctuation and overall byproduct levels would be to increase source water protection and cleaning efforts to maintain it at the best quality.

Obviously, the higher levels of HAAs and THMs indicate that people orally consume more of these chemicals when they drink water. Previously, oral consumption was the main focus when determining the regulatory levels. New studies are emerging that examine other routes of exposure. One of which is showering. Showering creates three routes of exposure to disinfection byproducts through the mouth (oral), skin (absorption), and lungs (inhalation).¹¹ Studies found that showering resulted in higher levels of chlorine byproducts in the blood than drinking approximately 1 liter of water.¹¹ Likely, inhalation is the source because the vaporized chemicals can transfer from the lungs to the blood without going through processing like oral consumption. When people consume food or drink, it is broken down into parts in the gastrointestinal tract where specialized tissues sort out what material to uptake and what materials should be excreted. Therefore, oral consumption can lead to a more selective uptake, reducing the amount of chlorine byproducts in the blood. To avoid increasing exposure in the shower consumers should shower with better ventilation and for shorter periods of time. The more time spent in the shower, the more exposure a person experiences.

Chlorine is not the only chemical disinfectant being used, there is a chlorine derivative called chloramine many water treatment plants are now using. As seen in the research above in Bloomington, chlorine byproducts are difficult to control and maintain at a specific level. Some municipalities struggle to maintain THM and HAA levels at the legal levels due to cost and other contributors. Retaining proper levels in areas with lower quality water or more dramatic fluctuations may require more expenditures to protect or clean source water prior to the treatment process. Some communities may not be able to financially support that, so they look for an alternative. Chloramines are often the answer in these cases. These chemicals have unregulated byproducts, meaning no laws have been put in place to limit the presence of chloramine byproducts in drinking water.¹² Therefore, communities that utilize these chemicals for disinfection do not need to monitor or limit these chemicals. This helps address the economic issues that treatment facilities face. Unfortunately, chloramines’ byproduct, iodo-trihalomethanes, show more genotoxic and cytotoxic effects than chlorine byproducts.¹² This can significantly impact human health by causing cell death and mutations which could lead to cancers. Since these chemicals are unregulated and un-measured, it is unknown how much is being consumed by a person with every glass of water. Thus, exposure could potentially increase and cause significant harm to individuals. Because most people are either unaware or blindly trust their water treatment systems, cities choosing to use chloramines may not face scrutiny by consumers.  There should be an increase in water treatment education for the average person so he/she can actively participate in policy, regulations, and fund distribution.

Another issue presented by introducing chemicals into water is the changes to its composition and increase/decrease chemical reactions. One study found that lower pH of water indicated lower levels of chlorine byproduct formation.¹³ Acidic water hinders the chemical reaction process between chlorine and organic matter; therefore, chlorine byproducts cannot be formed.¹³ On the surface level, it would seem desirable to have slightly more acidic water than neutral or basic. However, low pH levels in water can also have a deleterious effect by increasing its corrosivity thus causing the leaching of metals like lead and copper into it.¹⁴ Both metals have serious health effects at high levels. Flint, Michigan is still struggling to remove high concentrations of lead from their water systems. This crisis has been going on for years and proves the point of needing up-to-date treatment systems. With an understanding of chemical byproducts and corrosivity, it seems best to find a way to raise the pH levels back towards 7.0. This is neutral and should be best for our health, but to do it would require research on how to best protect source water and treat it.

I decided to do an at-home experiment that can be replicated by others.  Using pH test strips purchased from an online retailer, I tested tap water samples from 3 sources: my apartment in Bloomington, the tap water at my parent’s home in Avon, IN, and water from Aqua Systems. After exposure to the water, the pH strips change color to reflect the pH of the sample.  I repeated the test 3 times for each sample to find an average. The results are below:

Even among these three samples, there is a lot of variation in water pH. The pH of the water in Avon appears to be the closest to the “true” water pH. Perhaps, this is due to Bloomington being closer to limestone quarries which influence the mineral content in the water, making it “harder.” Aqua System utilizes a different treatment and purification process which may add in more minerals, chemicals, etc. that can influence the pH. None of the water samples seem particularly adequate, all indicate potential issues. Again, the best course of action would be to mitigate increases or decreases of pH past 7.0.

Disinfection byproducts and chlorination of water may have significant effects on people, but we are not the only organisms that need water. Our water treatment has impacts on our environment potentially increasing biodiversity loss. Aquatic life is most at risk as water is recycled through its systems and treated water changes the composition of lakes, rivers, and other systems.¹⁵ Aquatic organisms can be very sensitive to changes in mineral content, pH, etc. which then can make survival for individuals or species more difficult.¹⁵ Biodiversity loss has immense impacts on humans as well. Firstly, fish that die from environmental changes are sources of food and income for many people. Losing them will greatly impact food security and the economy. Some organisms in the water are natural cleaners and losing them will just increase the need to use chlorine to clean water, thereby increasing chlorine byproduct prevalence. The creatures that do not die from the presence of disinfection byproducts show bioaccumulation of THMs in fat stores.¹⁶ Therefore, our consumption of fish exposed to disinfection byproducts could create another route or ingestion of THMs and HAAs for people. We would, yet again, increase our exposure to these chemicals, increasing our risk of adverse health effects. All in all, finding ways to mitigate chemical use and spillover into the environment would be beneficial.

After all this research, I felt very uneasy. Water is supposed to be life-sustaining, not something that causes harm. I was curious if anyone else would feel the same when given some of my research, so I sent out a survey to friends and family. I sent it to 60 people and received 39 responses. The people involved in the survey were diverse, ranging in age from 18-86, varying socioeconomic status, student/employed, and political ideology. I decided to focus my questions on how this information made them feel and what would they like to be done. I asked first if they knew how water was treated in the US. Around 74% of respondents did not but 64% did know that the process involved the use of chlorine/chloramines to sterilize. When asked how they felt about chloramines being unregulated, 82% responded saying this made them feel uneasy and 10.26% said they needed more information to form an opinion. In general, most respondents agreed they would prefer more research to be done on water treatment and many also agreed that the current system’s benefits do not outweigh its costs. For a small survey, not much can be deduced from the data; however, it seems to reflect what the average American believes when presented with the information. Most importantly, education on the topic is minimal. A way to encourage policy changes and movement towards healthier water treatments would be to start the conversation and increase education.

 

 

Finally, are there any alternatives? Yes, there are several alternatives to chemical disinfection. The one that seems most viable is UV light. In the docu-series, the Parisian water treatment plant used UV light to kill pathogens in the water instead of chemicals.¹ UV light is very potent and actually more effective than chlorination; however, the technology costs more and requires more maintenance.¹⁷ The financial cost is the most likely reason UV disinfection is not used in most water facilities. Since the start of its use, chlorine has generally provided clean, bacteriologically safe water to people. So, it makes sense why many communities have not tried to change. However, a few have here in the United States: notably, New York City. New York has been integrating UV technology into the treatment process due to the health implications of chemicals.¹⁸ It has not become the main treatment process for the city, chlorine is still used in many plants as well to prevent bacterial growth in the pipes. It is still a move in the right direction and, hopefully, other cities will follow.

Water is not something people probably thought about in-depth. There are obvious issues like scarcity and cost that concern most people, but little thought on the risks of consuming it. Most of us, think that drinking tap water over other beverages represents a healthy choice: that doing so is the best thing for our bodies. It strange now, after all this research, to learn that maybe it isn’t the best thing. I can only hope that the rise of new technology, education, and water activism can help to reduce our reliance on chemical disinfection. In the end, this would provide us with healthier lives and environments by changing one simple thing, our water.

Work Cited

1. Zac Efron, Darien Olien, Down To Earth with Zac Efron, Netflix, July 2020
2. “Water Treatment.” Centers for Disease Control and Prevention. January 20, 2015. Accessed October 12, 2020
3. “Water Disinfection with Chlorine and Chloramine.” Centers for Disease Control and Prevention. November 17, 2020. Accessed December 14, 2020. https://www.cdc.gov/healthywater/drinking/public/water_disinfection.html#:~:text=Chlorination is the process of,of chlorine in drinking water.
4. “Disinfection By-Products.” Centers for Disease Control and Prevention. December 02, 2016. Accessed December 14, 2020. https://www.cdc.gov/safewater/chlorination-byproducts.html.
5. Bull, Richard J. “Health Effects of Drinking Water Disinfectants and Disinfectant by-Products.” Environmental Science & Technology, vol. 16, no. 10, 1982, doi:10.1021/es00104a719.
6. Li, Xing-Fang, and William A. Mitch. “Drinking Water Disinfection Byproducts (DBPs) and Human Health Effects: Multidisciplinary Challenges and Opportunities.” Environmental Science & Technology52, no. 4 (2018): 1681-689. doi:10.1021/acs.est.7b05440.
7. Backer, L., Ashley, D., Bonin, M. et al.Household exposures to drinking water disinfection by-products: whole blood trihalomethane levels. J Expo Sci Environ Epidemiol 10, 321–326 (2000). https://doi.org/10.1038/sj.jea.7500098
8. “Stage 1 and Stage 2 Disinfectants and Disinfection Byproducts Rules.” EPA, Environmental Protection Agency, 18 June 2020, www.epa.gov/dwreginfo/stage-1-and-stage-2-disinfectants-and-disinfection-byproducts-rules.
9. “City of Bloomington, Indiana.” Water Quality Information | City of Bloomington, Indiana, bloomington.in.gov/utilities/water-quality.
10. El-Attafia, Benhamimed, and Moulessehoul Soraya. “Presence and Seasonal Variation of Trihalomethanes (THMs) Levels in Drinking Tap Water in Mostaganem Province in Northwest Algeria.” Electronic Physician9, no. 5 (2017): 4364-369. doi:10.19082/4364.
11. Hunter, E. Sidney, et al. “Comparative Effects of Haloacetic Acids in Whole Embryo Culture.” Teratology, vol. 54, no. 2, 1996, pp. 57–64., doi:10.1002/(sici)1096-9926(199606)54:2<57::aid-tera1>3.0.co;2-1.
12. Richardson, Susan D., Francesca Fasano, J. Jackson Ellington, F. Gene Crumley, Katherine M. Buettner, John J. Evans, Benjamin C. Blount, Lalith K. Silva, Tim J. Waite, George W. Luther, A. Bruce Mckague, Richard J. Miltner, Elizabeth D. Wagner, and Michael J. Plewa. “Occurrence and Mammalian Cell Toxicity of Iodinated Disinfection Byproducts in Drinking Water.” Environmental Science & Technology42, no. 22 (2008): 8330-338. doi:10.1021/es801169k.
13. Hung, Yen-Con, et al. “PH Effect on the Formation of THM and HAA Disinfection Byproducts and Potential Control Strategies for Food Processing.” Journal of Integrative Agriculture, vol. 16, no. 12, 2017, pp. 2914–2923., doi:10.1016/s2095-3119(17)61798-2.
14. “PH in Drinking-water – World Health Organization.” Accessed December 14, 2020. https://www.who.int/water_sanitation_health/dwq/chemicals/ph.pdf.
15. Wastewater Treatment Water Use. Accessed December 14, 2020. https://www.usgs.gov/special-topic/water-science-school/science/wastewater-treatment-water-use?qt-science_center_objects=0#qt-science_center_objects.
16. Wang, Juan, Zhineng Hao, Fengqiong Shi, Yongguang Yin, Dong Cao, Ziwei Yao, and Jingfu Liu. “Characterization of Brominated Disinfection Byproducts Formed During the Chlorination of Aquaculture Seawater.” Environmental Science & Technology52, no. 10 (2018): 5662-670. doi:10.1021/acs.est.7b05331.
17. EPA, “Wastewater Technology Fact Sheet: Ultraviolet Disinfection.” Accessed December 14, 2020. https://www3.epa.gov/npdes/pubs/uv.pdf.
18. New York City Drinking Water Supply and Quality Report 2019.Report no. 2019. NYC Water Treatment. https://www1.nyc.gov/assets/dep/downloads/pdf/water/drinking-water/drinking-water-supply-quality-report/2019-drinking-water-supply-quality-report.pdf.