Scientists have developed a new method for identifying levels of exposure to environmental arsenic - by testing toenail clippings.
The research, published in the Journal of Environmental Monitoring, was carried out by experts at the Universities of Leicester and Nottingham Trent and the British Geological Survey.
Researchers used toenail clippings to find fresh evidence of exposure to environmental arsenic within a UK population living near a former arsenic mine.
Arsenic occurs naturally in the environment and members of the public can be exposed to it in several ways, for example through contaminated water, food, dust or soil.
And long-term exposure to arsenic has in the past been associated with increases in lung, liver, bladder and kidney cancers and skin growths.
Mark Button, from the University of Leicester, said the researchers had initially identified high levels of arsenic in earthworms living in contaminated soils surrounding the former mine, which led them to think about potential exposure in people living close to the site.
As part of the study, the researchers collected toenails and analysed the samples using inductively coupled plasma mass spectrometry.
'This preliminary research indicates that people living close to a former arsenic mine have elevated levels of arsenic in their toenails,' Dr Button said.
'However, the potential health risks in this case, if any, are not yet clear and no arsenic-related health issues have been reported. A large-scale and more detailed biomonitoring study is required to confirm these initial results.'
Dr Jenkin, a lecturer at the University of Leicester, added: 'This is the first time that the chemical form of the arsenic in the toenails has been measured - that can tell us something about how it got in there and possible risk factors.'