University of Louisville researchers have received $3.6 million in new grant funding to study the role of arsenic exposure in causing cancer and other major health concerns. And, they think there’s a simple, off-the-shelf solution — zinc — that could help prevent some of its worst effects.
Arsenic is highly poisonous and occurs naturally in some rocks and soil. As a result, the most common source of exposure is drinking contaminated water, particularly ground water from private wells. More than 43 million people in the U.S. alone get their water from private wells, including many in areas of Kentucky that may be contaminated from previous coal mining.
“What people don’t realize is that private wells and even public water supplies serving smaller numbers of people are not regulated,” said Chris States, a UofL School of Medicine researcher who’s been studying arsenic’s role in cancer for more than 25 years. “People using private wells for their water are on their own to test for toxic chemicals.”
Chronic exposure to low doses of arsenic, as from drinking water, can cause a host of serious health concerns, including cardiovascular disease, diabetes and several cancers, including skin, lung and bladder cancer. In high doses, arsenic can also be fatal.
States and collaborator, Mayukh Banerjee, backed by two new grants from the National Institutes of Health and American Cancer Society totaling $3.6 million, are working to discover what specifically about arsenic exposure can cause and accelerate the development of those conditions. Understanding this cause and effect could help researchers and public health officials find ways to keep people safe and healthy.
States and Banerjee believe it may all come down to how arsenic binds with proteins that help the body regulate the expression of genes. When gene expression isn’t properly regulated, your cells can begin to behave abnormally, mutating and multiplying out of control and not dying when they should. In other words, they become cancer cells.
Many proteins need zinc to do their jobs properly. When arsenic binds with these proteins instead, it takes the place zinc would normally fill. This disables these regulatory proteins and accelerates dysregulation.
Even worse, Banerjee said, is that there’s significant overlap between the communities who drink potentially contaminated well water and those who are more likely to have a zinc deficiency. If the body doesn’t have enough zinc to bind with the regulatory proteins in the first place, it can increase your risk of some of the same health concerns as arsenic exposure — including heart disease and cancer. An estimated 17.3 percent of the global population is zinc deficient.
“It’s a double whammy,” said Banerjee, an assistant professor of pharmacology. “The populations we’re talking about are largely impoverished and rural, who are already more likely to be zinc deficient because they don’t have access to healthy, nutritious foods. So, you have a lack of zinc in the diet exacerbated by arsenic preventing what zinc they have from doing its job in the body.”
There isn’t currently any medication that treats chronic arsenic exposure. However, Banerjee said, there may be a simple, over-the-counter solution — if the problem is a lack of zinc, it may be treatable with a zinc supplement. His research has shown zinc supplementation can mitigate or even regress some of the worse effects of arsenic exposure.
“Zinc is over-the-counter, which makes it cheaper and readily accessible,” Banerjee said. “But I don’t think a lot of people are even aware of the potential danger of well water or what it can cause. We really hope this work can help those people.”
