To prevent harmful bacteria and microorganisms from being present in water sources and water distribution pipes, most countries add chlorine to their municipal water supplies to treat and eliminate bacteria and microorganisms. However, because chlorine is an extremely reactive oxidizing agent, it forms byproducts that are harmful to human health when it comes into contact with fatty acids in animals or humans, as well as other water-soluble or volatile chemical substances (VOCs). Experiments have shown that these byproducts can cause skin allergies, high blood pressure, and heart disease; in severe cases, they can even lead to terminal illnesses such as liver cancer, stomach cancer, bladder cancer, and colon cancer.

Studies indicate that chlorine and its byproducts (such as THMs) can enter the body through the skin and respiratory system while showering, causing harm. They can also spread to other areas of the home, polluting the air and affecting every member of the household. By conservative estimates, during a ten-minute shower, the body absorbs a concentration of byproducts through the skin and respiratory system equivalent to drinking eight glasses of water.

Preventive measures include avoiding the consumption of chlorinated tap water as much as possible. You can install a chlorine-removing filter on your tap. When showering, use an effective showerhead filter and a central water purification system.

By Michael Chiu, MWS, CI
Previously published in Ming Pao Daily News