Toenail test could catch the drug cheats

Fingernails and toenails could soon be used to catch drugs cheats in athletics as well as users in the office.

Scientists in Scotland, working with a group of academics in London, have developed a system that can identify drug traces embedded in nail clippings. These traces can take between 3 and 12 months to reach the end of the fingers.

"In terms of sensitivity, this is similar to other methods. But especially compared to urine testing, this has a longer span over which it can detect drug use," said Dr Robert Anderson, of the forensic science department at the University of Glasgow.

Urine testing, commonly used to test athletes for the use of banned substances around competition, has the weakness that they only detect the breakdown products of drugs from a maximum of a few weeks beforehand. Athletics officials are convinced that abuse occurs but is often carried out before competition, in time for traces to vanish from the metabolism by the time of testing.

"We can actually detect heroin if someone has taken it ­ it gets deposited in the nail bed and carried out," said Dr Anderson.

Only 10 milligrams of nail is required, not necessarily from the same nail, for these new tests. Fingernails take up to six months to grow, and toenails take between six months and a year to grow from the nail bed to the end.

Random drug tests are already becoming commonplace in the workplace, where train drivers, prison officers and military personnel must face them as it is illegal for a company to allow intoxicated staff to endanger lives at work.

The General Medical Council is also now believed to be considering the introduction of random drug testing. Some 15 per cent of doctors are believed to suffer from either a drink or drugs problem during their lives.

One problem that the "nail test" might face is that for recent recruits, it could identify drug taking that occurred before they started employment ­ from which they would arguably be exempt.

Hair testing can check for drugs taken some months before, which will be deposited in the collagen of the strand during the hair's growth. But this is not such conclusive evidence. Dr Anderson pointed out: "If you're in a room with people who are smoking cannabis, then it will get deposited in your hair and could show up in a test."

The same problem could occur with the nail test, he admitted, but with proper preparation any contaminants can be removed from the surface, leaving only the embedded drugs in the nail.