Drinking California tap water for long period of time could increase cancer risk, study says

SAN FRANCISCO (KGO) -- Cancer and water, two words that no one wants to hear in one sentence.

"One person in a population of a million will develop cancer in their lifetime," said Environmental Working Group scientist, Tasha Stoiber.

After a yearlong research looking into California water data from 2010 to 2015, Dr. Stoiber, along with her colleagues, found that every day Californians are exposed to contaminants that can cause cancer, one drop at a time.

"Arsenic is related to lung cancer and skin cancer, disinfectant bio products are associated with bladder cancer and other types of cancer," said Stoiber.

We contacted East Bay Municipal Utility District and San Francisco's Water District to see what they are doing to prevent these contaminants from sneaking into your tap water.

"Our customers can trust that EBMUD water is completely safe. We disinfect, treat and filter every single drop of water that goes to our customers. EBMUD meets or surpasses all federal and state standards," said EBMUD spokesperson, Andrea Pook.

San Francisco's water district responded: "We test our water more than 100,000 times annually throughout the system to ensure we consistently meet or exceed state and federal standards..."

The Environmental Working Group study found those contaminants could contribute to tens of thousands of cancer cases in California over the course of 70 years.

"Estimated 15,000 cases from drinking water exposure," said Stoiber.

Now, would boiling water kill these contaminants? The answer is no, boiling water will only kill bacteria! Our best bet according to this study is to filter your water. But not everyone has access to filtered water.

"Systems that had the highest cancer risk served smaller communities and served less than 10,000 residents"

To check the contaminants in your water click here.

To read the complete research paper go here.