An important tool for maintaining clean drinking water can be more risky than we thought. New research finds a connection between water chlorination and an increased risk of certain cancers.
Scientists at the Carolinska Institute in Sweden have been conducted by research, which is an overview of past studios that observed chlorination and cancer. They have discovered evidence that people are exposed to the highest level of chlorine by -products are significantly more likely to develop bladder cancer and colorectal cancer than people exposed to the lowest levels. This connected risk has been recorded starting at the level below the security thresholds established in the United States -UI, which suggests that current guidelines are not sufficient to protect the public, the researchers say.
The chlorine was routinely used disinfect drinks and recreational water from the beginning of the 20th century. Helped eradicate or reduce the spread of dangerous diseases such as typhoid fever and cholera. But chlorine and other disinfectant are known to have their disadvantages. One of the main disadvantages is to create disinfectant by -products, created by these chemicals that are mixed with organic compounds in raw water, and the most prominent by -products from the chlorine are called trihalometane (THMS). Past research He showed that THMs could cause cancer, at least in rodents, but studies who questioned whether THM were in chlorinated water related to cancer in humans more mixed.
Early data examinations were generally found limited evidence connections between thm -a bladder and colon cancer. But these reviews have been more than a decade and there have been more recent, potentially informative studies on the topic published since then. Thus, the scientists of Caroline sought to conduct their own updated metaanalize research.
Finally, they analyzed data from 29 papers, the latest published last year. Although most studies watched the bladder and colorectal cancer, 14 cancer was estimated. Researchers failed to find a significant connection between the exposure of the THM -UI any other cancer except them. But they found that the highest levels of THM (compared to the lowest) are associated with 33% higher risk of bladder cancer and 15% higher risk of colorectal cancer. It is important that this added risk has appeared at ThM levels starting at 41 parts per billion (PPB) -in the USA -ui border of 80 PPB in the United States -Ui limit of 100 PPB in the EU.
“In conclusion, in this systematic review and metaanalysis of dose-speaking, we have revealed limited suggestive evidence that the exposure to TM in drinking water increases the risk of bladder cancer and colorectal cancer,” researchers wrote in their work, published this January in Environmental health perspectives.
There are other technologies that can disinfect drinking water today, such as ultraviolet light treatment. And practices such as eliminating organic substances from water before being treated with chlorine can potentially reduce thM levels. However, researchers fully acknowledge that the data collected so far are not enough to prove the causal-effect connection between chlorination and cancer. They also do not tell the public that cold turkey go because of drinking tap water based on their findings. At the same time, they urgently call for well -conducted research to consider and confirm this possible risk.
“What we see is alarming and we need some other quality studies,” said lead researcher Emilie Helte Guard.