In the US, contaminated tap water causes 100,000 cancer cases over a lifetime, as revealed by a new study published in the peer-reviewed journal Heylion, by scientists associated with the Environmental Working Group.
According to the analysis, greatest cancer risk is from naturally occurring arsenic, the resultant byproduct of chemicals used to disinfect water and radioactive contaminants.
Sydney Evans, lead author of the study, “We want people to realize that water that meets legal specifications may still cause health risks based on the latest science. This is a concern nationwide, whether urban or rural, with a small or large [water system].”
The number of cancer cases from water contamination is slight as compared with the total number of cancer cases in the US. In the year 2018, the American Cancer Society reported almost 1.7m new cancer cases. Considering a lifetime to be 70 years, that adds up to many millions of cases of cancer.
Nevertheless, Olga Naidenko, vice-president of science investigations at the Environmental Working Group, reiterated that water contamination is accountable for a high percentage of the cancer cases that originate from environmental causes.
The US is graded well for water quality as it has mostly eliminated biological contaminants like the bacterium E Coli, which are more rampant in developing nations.
However, other dangerous contaminants remain to pose a problem.
Problems in small, rural communities have been well recognized, but the study submits that pollutants in the water in large communities can also “contribute a significant share of overall cancer risk associated with drinking water”.
The researchers investigated water quality profiles from over 48,000 water systems. Evans recommends that people should check their local water reports and select an appropriate filter if needed. The Environmental Working Group keeps a drinking water database for this purpose.
For example, in Washington DC, regulators higher levels of 10 contaminants than health guidelines but these are recommendations and not requirements. Unfortunately, most are associated with cancer so individuals should become aware of their local water system.