Tap water may altogether increase cancer risk for thousands of U.S. residents over a lifetime

Experts say that the risk of these carcinogens have been under debate for decades. They caution that the standards set for community water systems

EWG found that per 10,000 people, four will have cancer over the span of the lifetime due to the contaminants in water

EWG said that 87% of the cancer risk present in tap water comes from arsenic and byproducts of common disinfectants

A spokesperson with the EPA told USA TODAY that water regulations focus primarily on the contaminants that may cause the greatest public health risk

Meanwhile, the EWG recommends that only four ten-thousandths of a microgram (0.0004 micrograms) of arsenic be allowed in water

Regulations for drinking water in the United States are based on a complex balance between health risks from possible carcinogens

On a broader scale, experts advise solutions aimed at reducing the level of contaminants that are present in tap water.