Just what we need--a more intrusive alcohol test. But that's what's coming down the pike. A new test is being developed that will detect drinking over months:

Tests which can show how much someone has drunk in previous weeks and months and not just in the past few days are being developed, it was reported today. The new research is likely to benefit not only doctors but police investigating a crime and could attract the interest of employers and insurance companies.

The tests could let a GP know if someone is a light or heavy drinker and tell investigators if a driver or worker involved in an accident was drunk at the time, even if they were not tested until days later, reported the New Scientist magazine.

The New Scientist article is here. Among the uses it predicts for the new tests:

Doctors are likely to be the first to employ some or all of the new tests, to monitor patients with alcohol problems. But they are also likely to attract the interest of employers, insurance companies and forensic scientists. Airlines could, for instance, identify pilots who are heavy drinkers by testing their hair. A urine test might allow police to prove many hours or even days after an accident that someone had been drinking.