A newly updated database from the nonprofit Environmental Working Group (EWG) documents nearly 280 contaminants lurking in US drinking water.
Two of the most prevalent and concerning chemicals, arsenic and hexavalent chromium, were found in drinking water in all 50 states.
Both chemicals are known carcinogens commonly found in California taps.
In 2017, the nonprofit Environmental Working Group (EWG) released a database of all the known contaminants lurking in US drinking water. After compiling data from 50,000 public water utilities across the country from 2010 to 2015, the group found 267 chemicals that they dubbed concerning to human health.
On Wednesday, the group announced an update to those findings: After analyzing the same data set from 2012 to 2017, the EWG found 278 contaminants in US drinking water.
The health risk of each contaminant is “going to vary region by region, state by state, utility by utility,” Tasha Stoiber, a senior scientist at EWG, told Business Insider.
To enable people to learn about the contaminants in their drinking water, the EWG database allows anyone to look up their ZIP code, find a list of contaminants in the local water supply, and determine what type of filter could help weed out these chemicals.
Two of the most prevalent and concerning chemicals found, Stoiber said, were arsenic and hexavalent chromium. Both chemicals were detected in all 50 US states, though they appear especially often in California groundwater. They’re also known to cause cancer.
Arsenic was found in the taps of 107 million Americans
From 2015 to 2017, the EWG detected arsenic in the tap water of 107 million Americans. In California alone, it lurked in the taps of more than 26 million people. In Texas, more than 17 million people had arsenic in their tap water. In Florida, more than 11 million people were exposed.