Disinfecting the public drinking water supply and treating swimming pools is a major application of public health practices to protect the public from infections transmitted by contaminated water. Chlorine is one of the sterilizers and the most widespread disinfectant used worldwide but may make you sick over the long term. Chlorination of water started in the early 20th century as an innovative solution to water-borne diseases. However, the use of chlorine to disinfect water later became a concern because of long-term health problems, as scientists have concluded that disinfectants may react with other chemical substances in our water.
Chlorine is the chemical of choice in water disinfection due to its effectiveness. However, chlorination can have unintended consequences, such as being able to react with other things in tap water, such as organic materials for forming known halogenated chemicals by-products of disinfection (DBPs). Many halogen compounds are known to cause cancer. Common disinfection by-products are trimethane (THM), haloacetic acids (HAA), and bromate, Chlorite, and chlorate. Although more than 600 different DBPs have been identified, they are generally considered ’emerging pollutants’, with around 50% not yet recognized.
Most people may not know that pool chlorination used to kill bacteria, viruses, protozoa, and algae also produce disinfection by-products (DBPs). Many DBPs products are considered toxic and dangerous to human health.DBPs are a group of compounds that are produced during the disinfection process of drinking water, pool water, and sewage. In the disinfection process, disinfectants, such as chlorine, chloramines, chlorine dioxide, or ozone, are used to kill pathogens in water. However, during this process, sanitizers may react with compounds containing halogens and natural organic matter (NOM) to form DBPs.
There are significant health risks associated with DBPs due to long-term exposure. While some cleaning byproducts contain virtually no toxicity, research shows that others have been linked to cancer, reproductive problems, and growth problems.DBPs may enter the human body by drinking water contaminated with DBPs, by inhalation of DBPs, or by the skin during showering. Continued use of sanitizers results in the formation of potentially hazardous by-products. The Environment Protection Agency has developed a set of secondary disinfection regulations to reduce exposure to DBPs. To reduce DBPs, some water systems are using more and more chloramine as a disinfectant, which is safer than chlorine, due to its tendency to produce fewer by-products. However, chlorine is still the dominant disinfectant in the water supply.
While regulatory authorities took measures to reduce disinfection by-products through pre-oxidation or filtration of organic precursors, the most effective way to minimize your exposure is to filter water at the point of use, and/or drain stagnant water from the pipes, letting it run for a few minutes before use. If you are concerned about DBPs in your water, you can have a laboratory water test carried out. It warns you of the presence of disinfectant by-products in your drinking water, including chloroform, bromodichloromethane, dibromochloromethane, and bromoform.
No matter how water is treated in domestic systems, disinfection by-products will continue to be a very real threat. That is why we must look for alternative solutions before it is too late.