According to USA Today, a new report from an environmental advocacy watchdog group cautions that carcinogenic products in tap water may altogether increase cancer risk for thousands of U.S. residents over a lifetime.

Faucets dispense water with a number of contaminants, and the health effects of those combinations need to be researched.

An Environmental Working Group found that 22 carcinogens commonly found in tap water, including arsenic, byproducts of water disinfectants and radionuclides such as uranium and radium could cumulatively result in over 100,000 cancer cases over the span of a lifetime.

Experts say the risk of these carcinogens has been debated for decades. They caution that the standards set for community water systems, which are regulated nationally by the Environmental Protection Agency, are complicated and require a balance between cost and safety.