Water is life's essence, but what if the very water you consume daily is quietly poisoning you? A new study by the World Journal of Gastrointestinal Oncology has uncovered shocking issues—long-term drinking of chlorinated water can raise the risk of a number of cancers, such as bladder, colorectal, and kidney cancer.



Why is chlorine added to drinking water?



In India, where cholera, typhoid, and dysentery are still common waterborne diseases, chlorine is extensively utilized as a disinfectant to eliminate pathogenic bacteria and viruses. It has been a cornerstone of public health and made sure millions of people had access to clean drinking water. But there is a hidden cost to this convenience.



How does chlorinated water become harmful?



Dr. Neeraj Dhingra, Consultant in Radiation and Clinical Oncology at Ruby Hall Clinic, Pune, says, “Although chlorine itself is not carcinogenic, upon interaction with natural organic matter like leaves, soil, and algae in the water, it creates toxic chemical byproducts, including mostly trihalomethanes (THMs) and haloacetic acids (HAAs). These have been associated with DNA damage, which induces cancerous cell growth.”










According to Dr. Aravind Badiger Technical Director BDR Pharmaceuticals, “The latest report links drinking chlorinated water with a much higher risk of cancers, which has consequences in the pharmaceutical industry. Chlorine is commonly used in water treatment, but it can also form disinfection byproducts such as trihalomethanes (THMs), which can be connected to carcinogenic effects. For pharmaceutical companies, it is precisely the recommendation to conduct further research on the long-term health harms of chlorinated water consumption. Pharmaceutical companies may need to partner with regulatory agencies to develop better methods for purifying water or treatments that are toxic neutralizing harmful byproducts when using stricter guidelines to safeguard public health.”



Cancer risk from chlorinated water



Bladder cancer since these chemicals become concentrated in the bladder over a period of time. Colorectal cancer as a result of long-term exposure that impacts the health of the gut.

Kidney cancer, since the kidneys purify these toxins, causing cell damage.

Who is most at risk?

• Urban dwellers who drink chlorinated municipal water every day.


• Rural communities with irregular water treatment, resulting in uncontrolled chlorine levels.


• Pregnant women and children, since exposure to THMs has been linked to developmental hazards.

Individuals with pre-existing health conditions, such as kidney disease or compromised immune systems.

What can be done to reduce the risk?



Though removing chlorine from public water systems is not possible because of its function in preventing disease, individuals can reduce exposure in the following ways:

• Employ activated carbon filters – These can efficiently remove chlorine and its byproducts.


• Boil water prior to drinking – Although this will not eliminate THMs, it can decrease total chlorine content.


• Choose other purification techniques – Reverse osmosis (RO) and UV filtration offer safer disinfection with no toxic residues.


• Store water effectively – Allowing tap water to stand in an uncovered container for a few hours enables some chlorine to evaporate.


• Demand improved water regulation – Require safer water treatment practices that prioritize the reduction of toxic byproducts.