Researchers can now track a subject’s exposure to arsenic by examining nail clippings.
A team of Duke researchers—lead by Avner Vengosh, professor of earth and ocean science—conducted a study in the Rift Valley of Ethiopia that detects arsenic levels in water. The new test has potential implications for tracking levels of arsenic exposure domestically.
“Toxic contaminants are often measured in drinking and other dietary sources, however, biological markers such as urine, nails and hair are also good markers of human exposure to contaminants such as arsenic,” said Tewodros Rango, a postdoctoral research associate in Vengosh’s lab.
He noted that arsenic in nail and hair can provide an estimate of long-term exposure--—unlike urine, which can only indicate short-term exposure.
This is the first study to examine the levels of arsenic exposure in the Rift Valley, said Brittany Merola, a Ph.D student at the Nicholas School of the Environment.
“There’s never been an arsenic assessment in the Rift Valley, which is why it is so important,” Merola said. “The problem is there is not only contamination from toxins like fluoride, but also high contamination from arsenic in water.”
Arsenic contamination of water supplies is a growing environmental issue and affects groundwater in diverse parts of the world, said Mark Jeuland, assistant professor of public policy and global health. He added that arsenic is a naturally occurring contaminant, coming mainly from rocks beneath water sources.
Arsenic exposure leads to many health risks and is very expensive to remove from groundwater supplies, Rango said.
“Cancer is the main disease manifestation on the skin and the internal organs of exposed populations,” Rango said.
The study not only had findings showing that arsenic is a huge problem in the Rift Valley, but it also demonstrated the effects of nutrition on arsenic levels in the body, Merola said.
“People with better nutrition had lower arsenic even if they consumed the same amount of water,” Merola said. “People know that individuals who have better nutrition have lower occurrences of certain arsenic effects, but we’ve never seen lower concentrations of arsenic in the body from better nutrition.”
The study in the Rift Valley is ongoing, as researchers are now testing how fluoride is impacting Ethiopian water sources.
Duke researchers are also currently conducting a case study in Charlotte where arsenic contamination poses a threat to water sources, Merola said.
“We are actually working with the Union County Board of Public Health,” Merola said. “They know they have arsenic in their water and this could be affecting the health of the people who live there.”
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