A cough drop and a glass of water are placed on a stool
Representational image Reuters

At least 100,000 cancer cases have been reported over a lifetime due to contaminations present in the tap water in the US, a new study has found.

According to the study from scientists with the Environmental Working Group, US residents face the most dangerous cancer risk from naturally occurring arsenic, the byproducts of chemicals used to disinfect water and radioactive contaminants.

The cumulative cancer risk for drinking water contaminants is similar to the range of cumulative cancer risks reported for air pollutants within different states of the US, said the findings of the study published in the peer-reviewed journal Heylion.

The scientists stressed that decreasing the levels of chemical contaminants in drinking water represented an important opportunity for protecting public health.

"We want people to realize that water that meets legal specifications may still cause health risks based on the latest science," lead author Sydney Evans explained, adding the concern was identical in urban or rural, with a small or large water system.

The researchers of the study that examined water quality profiles from 48,363 systems, recommended people to check their own local water reports and select a suitable filter. They added that compliance with national drinking water standards did not mean water contaminant levels were reduced to concentrations without health risk.

"The majority of the cancer risk and estimated lifetime cancer cases correspond to community water systems that are in full compliance with drinking water standards," the lead author suggested.

The number of cancer cases from water contamination is, however, small compared with the total number of cancer cases in the US, according to American Cancer Society, which reported about 1.7 million new cancer cases in 2018.

The new findings come as another US study claims up to 21 million Americans get water from systems that violate health standards.

The US is ranked well for water quality as the country has largely eliminated biological contaminants such as the bacterium E Coli, which are more common in developing nations, but other dangerous contaminants remain problematic.