Water Chlorination Might Be Raising Our Risk Of Certain Cancers

Arthur T Knackerbracket has processed the following story:

An important tool for keeping our drinking water clean may be riskier than we thought. New research finds link between water chlorination and an increased risk of certain cancers.

Scientists at the Karolinska Institute in Sweden led the research, which is a review of past studies looking at chlorination and cancer. They found evidence that people exposed to the highest levels of chlorine byproducts were significantly more likely to develop bladder and colorectal cancer than people exposed to the lowest levels. This associated risk was seen starting at levels below the safety thresholds established in the U.S. and Europe, suggesting that current guidelines aren't enough to protect the public, the researchers say.

Chlorine has been routinely used to disinfect drinking and recreational water since the early 20th century. It's helped eradicate or reduce the spread of dangerous diseases like typhoid fever and cholera. But chlorine and other disinfectants are known to have their drawbacks. One major downsideis the formation of disinfectant byproducts, created by these chemicals mixing with organic compounds in raw water, and the most prominent byproducts from chlorine are called trihalomethanes (THMs). Past research has shown that THMs can be cancer-causing, at least in rodents, but studies examining whether THMs in chlorinated water are tied to cancer in humans have been more mixed.

They ultimately analyzed data from 29 papers, the latest published just last year. Though most of the studies looked at bladder and colorectal cancer, 14 cancers in total were evaluated. The researchers failed to find a significant link between THM exposure and any other cancers besides the two. But they found that the highest THM levels (relative to the lowest) were associated with a 33% higher risk of bladder cancer, and a 15% higher risk of colorectal cancer. Importantly, this added risk appeared at THM levels starting at 41 parts per billion (ppb)-below the 80 ppb regulatory limit in the U.S. and the 100 ppb limit in the EU.

Read more of this story at SoylentNews.