London: Scientists have claimed that our toenails can indicate if we are going to have lung cancer.
Clippings could be used to predict the risk years before the disease actually develops, they suggest.
In a study conducted to measure nicotine levels in toenail samples from both smokers and non-smokers, the team of scientists at the University of San Diego in California, found those with the highest readings were over three times more likely to get cancer than those with the lowest, The Sun reports.
Over 10 percent with the highest levels had never smoked.
The experts said their findings give an indication of the damaging effects of passive smoking.
Toenails grow around one centimetre a year - far slower than fingernails - so provide better clues on long-term exposure to cigarette smoke.
"Our study shows toenail nicotine levels provide a biomarker that can predict the risk of lung cancer independent of reported smoking history," the team said.
The team, which tracked the health of 850 men for up to 12 years, had previously found raised nicotine levels in toenail clippings also meant a greater risk of heart disease.