Cleaner Tap Water Could Prevent 50,000+ Cancer Cases in the U.S., Shocking Study Finds

If you’ve been thinking about installing a water purifier, a new study from the Environmental Working Group (EWG) just might be the final push you need. While water filter pitchers like Brita are helpful for removing chlorine, lead, and other impurities from tap water, they don’t reduce levels of toxic water chemicals, such as nitrate and arsenic. But EWG researchers might have found a solution—one that could drastically reduce cancer cases in the U.S.

RELATED: These 4 States Have the Lowest Quality Tap Water, New Data Uncovers.

Removing toxic chemicals from drinking water could protect 50,000+ Americans from cancer.

A new peer-reviewed study by the EWG found that better regulation of tap water contaminants in the U.S. could prevent over 50,000 cancer cases. The report was published in the journal Environmental Research.

Under current federal guidelines, tap water regulation is restricted to one contaminant at a time—commonly, nitrate. However, by treating two contaminants simultaneously, the U.S. could see an immense reduction in cancer cases.

Their “multi-contaminant approach” targets two cancer-causing chemicals found in more than 17,000 community water systems. These are arsenic and hexavalent chromium (chromium-6).

After analyzing more than a decade’s worth of data, researchers discovered that arsenic and chromium-6 often coincide in drinking water systems. Thus, a dual elimination process could be both time- and life-saving.

“If water systems with chromium-6 contamination also reduce arsenic levels to a range from 27 percent to 42 percent, it could avoid up to quadruple the number of cancer cases compared to just lowering chromium-6 levels alone,” a press release explains.

“Drinking water is contaminated mostly in mixtures, but our regulatory system still acts like they appear one at a time,” commented lead study author Tasha Stoiber, PhD, a senior scientist at EWG. “This research shows that treating multiple contaminants together could prevent tens of thousands of cancer cases.”

RELATED: New Study Uncovers the “Potential Risks” of Bottled Water and Why You Should Drink Tap Instead.

Cancers and other health risks are associated with water contaminants.

Nitrate has long been considered one of the most common—and dangerous—drinking water contaminants. But a new report from the EWG also highlights concentrations of arsenic and chromium-6 in U.S. tap water. All three have been linked to various types of cancers.

Arsenic

Arsenic is found in drinking water in all 50 states; however, contamination levels are highest in Arizona, Texas, and California. According to the press release, nearly eight out of 10 preventable cancers in California are associated with arsenic exposure.

Arsenic is a naturally occurring mineral that “leaches from rocks into groundwater that might be used for drinking or irrigation,” explains the EWG. On farms, it can seep into rice plants, fruits, and vegetables via the soil and water. Mining, metal production, coal power plants, and the burning of fossil fuels also contribute to arsenic pollution.

Studies show that arsenic pollution can cause skin, lung, bladder, kidney, and liver cancers. Researchers have also identified correlations between chronic arsenic exposure and dermatological, neurological, respiratory, cardiovascular, immunological, endocrine, and developmental issues.

Under current Environmental Protection Agency (EPA) guidelines, which were established in 2001, the legal limit for arsenic in drinking water is 10 parts per billion (ppb), per the EWG. However, a 2023 report from the EPA’s Integrated Risk Information System program concluded that arsenic is “30 times more toxic than previously estimated.”

Chromium-6

More than 260 million Americans have chromium-6 in their drinking water. The cancer-causing chemical is known to harm the liver and reproductive system.

Chromium-6 can be found in textile dyes, paints, and inks. The chemical is also used during industrial and manufacturing processes, such as anti-corrosion metal coating and wood preservation.

“It has been detected in groundwater because of these industries’ pollution, and from natural gas compression stations that use it as an anti-corrosion agent in cooling water,” explains the EWG.

The EWG’s tap water database shows that 7,583 water utilities across the U.S. have traces of chromium-6. This is a nationwide problem affecting all 50 states, with California, Texas, New York, and Florida showcasing the highest concentrations.

Nitrate

Of the three chemicals, nitrate is the most common contaminant. Drinking water in the U.S. can have high nitrate levels “due to upstream pollution from farms, stormwater run-off or the deliberate release of municipal wastewater into waterways,” says the EWG. “Excessive” rates of nitrate are also common in private wells.

According to a peer-reviewed EWG study, nitrate is linked to colorectal, ovarian, thyroid, kidney, and bladder cancers. It’s estimated that nitrate-polluted drinking water causes up to 12,594 cases of cancer annually in the U.S. Additionally, low birth weight and premature birth have also been associated with incidences of nitrate-polluted drinking water.

In recent history, Delaware, Arizona, California, and Iowa were known to have some of the highest concentrations of nitrate in their drinking water. It’s also a growing concern in the Midwest, a huge spot for agriculture.

“The federal nitrate limit was set decades ago to prevent infant deaths, but we now see cancer and birth complications at levels of nitrate far below that outdated standard,” Anne Schechinger, EWG’s Midwest director, said in the release.

“Even lowering nitrate slightly could prevent hundreds of cancer cases and save tens of millions of dollars in health care costs, especially when paired with treatment for other contaminants, such as chromium-6 and arsenic,” she continued. “There’s a real cost to inaction—our health and our wallets can’t afford to wait for better treatment.”

Environmental experts say a 20 percent reduction in nitrate levels could prevent 130 U.S. cancer cases annually.

“This is about more than clean water—it’s about protecting health and advancing equity,” said David Andrews, PhD, acting chief science officer at EWG. “We have the engineering solutions to fix the broken drinking water system in the U.S., but we need state and federal policies to reflect the reality people face when they turn on the tap.”