Author: Dunia Rassy
Institution: London School of Hygiene and Tropical Medicine
After detecting high levels of arsenic in the earthworms living near a mine, British scientists came up with an unusual way to detect human exposure to the chemical - by testing toenail clippings. The researchers from Nottingham Trent University, Leicester University, and the British Geological Survey published their findings on the Journal of Environmental Monitoring.
So how can our toe nails show how much of the infamous metallic element?
The scientists first collected toe-nail clippings from people living near an abandoned arsenic mine. These were washed and freeze-dried to obtain a contamination-free toenail powder. Arsenic was isolated by acid digestion and microwave irradiation, which dissolves and precipitates metals. It was then properly identified by inductively coupled plasma mass spectrometry, which detects metallic molecules accurately from small concentrations. The method effectively detected high arsenic levels in all people in the study.
When arsenic enters our body through food, water, dust, or soil, it disrupts metabolism. The disruptions may then lead to defective, cancerous cells. In large doses, arsenic produces multi-system organ failure. Current methods of diagnosis include measuring its levels in urine or blood. Hair samples can be used to measure exposure to high-levels, as those found in the bodies of King George III and Napoleon Bonaparte.
The findings, part of PhD student Mark Button's project, have opened the way for a dozen new questions concerning arsenic exposure: How does it get to toenails? What may be a risk factor? Can the results be coupled to blood arsenic analysis? Gawan Jenkin from Leicester University is eager to find the answers, but first a larger study must be carried out. Besides confirming their results, they must determine if arsenic concentrations in the toenail are modified with time.
For the time being, bad-looking toenails do not necessarily mean a person has been exposed to arsenic. In people with elevated amounts, it does not account for more that 0.003% of the toenail. "If a nail looks different from normal that is usually due to physical damage (you stubbed your toe or dropped something on it) or a minor fungal infection that can be easily cleared up by a visit to the doctor" clarifies Jenkin.
For those worry-warts, he also adds not to send him any of your toenail clippings to analyze.
Written by: Dunia Rassy
Edited by: Jeff Kost (News and Features Editor) and Nira Datta (Professional Reviewer)
Published by: Hoi See Tsao