Every day, millions of people drink chlorinated tap water. Chlorine is used to keep our water clean by disinfecting it and killing germs. And it does a marvelous job at eliminating most pathogens from the water we drink.
But the use of this powerful chemical has a downside. According to a report from the U.S. Council of Environmental Quality, the cancer risk for people who drink chlorinated water is up to 93% higher than for those whose water does not contain chlorine.
Chlorination is the process of adding chlorine to drinking water to disinfect it and kill germs. Different processes can be used to achieve safe levels of chlorine in drinking water. Chlorine is available as compressed elemental gas, sodium hypochlorite solution (NaOCl) or solid calcium hypochlorite (Ca(OCl)2. While the chemicals could be harmful in high doses, when they are added to water, they all mix in and spread out, resulting in low levels that kill germs but are still safe to drink
When chlorine was first introduced to the water supply, it brought a rapid reduction in the spread of disease and other water-borne ailments. It made it easier for cities and towns to purify drinking water and to keep their residents safe.
Legionella continues to be the most frequently reported etiology among drinking water–associated outbreaks. All of the outbreak-associated deaths reported during this surveillance period as well as all of the outbreaks reported in hospital/health care settings or long-term care facilities, were caused by Legionella. A review of 27 Legionnaires’ disease outbreak investigations in which CDC participated during 2000–2014 identified at least one water system maintenance deficiency in all 23 investigations for which this information was available, indicating that effective water management programs in buildings at increased risk for Legionella growth and transmission (e.g., those with more than 10 stories or that house susceptible populations) can reduce the risk for Legionnaires’ disease. Although Legionella was detected in drinking water, multiple routes of transmission beyond ingestion of contaminated water more likely contributed to these outbreaks, such as aerosolization from domestic or environmental sources.
Now, however, it seems like these advancements have come at a price. While we recognize and applaud the benefits chlorine has brought to us, it’s time we also protect ourselves from the harms of drinking chlorine – particularly because that turns out to be a pretty easy thing to do for your health and the health of your family.