On Dec. 2, 2024, researchers from the Texas A&M University School of Public Health reported a study that showed exposure to even low levels of arsenic poses significant health risks, including an increased risk of kidney cancer. The incidence of kidney cancer in the United States rose by an average of 1.2 percent each year between 2011 and 2019 to become the seventh most common cancer. In the meantime, smoking — a well-established risk factor for kidney cancer — has continued to decline.

This led researchers to consider other possible contributing factors, including arsenic, a known cause of various cancers that is naturally occurring in groundwater in Texas and other areas. Unlike previous studies, the Texas A&M study focused on low levels of arsenic exposure (below the regulatory threshold of 10 parts per billion) in both public water systems, which are regulated by various government agencies, and private well systems, which are not regulated.

The team examined the relationship between kidney cancer rates and arsenic levels in drinking water across 240 Texas counties. The analysis found that exposure to between 1 and 5 parts per billion raised kidney cancer risk by 6 percent, and exposure above 5 parts per billion raised the risk by 22 percent. In addition, the risk of cancer increased by 4 percent with each doubling of water arsenic levels. The study findings were published in Environmental Pollution.