Innovation: Hair of the drug

A COMPANY in Cardiff can now detect illicit drug-taking by analysing hair, rather than taking urine samples. The service can be used for workplace testing. Tricho Tech, partly funded by charity, was set up to develop technologies that could detect and monitor alcohol and drug abuse. Testing hair rather than blood or urine gets round the problem of sample substitution.

Since most drugs disappear from urine or blood within two or three days, intermittent use is easy to conceal. But traces are deposited permanently within the hair shaft in small quantities. Hair analysis can indicate the level and frequency of drug use over time.