"Given a choice, I would never work in a mine," says Wang dressed in a pair of old jeans, white tennis shoes and a brown artificial leather jacket, dirt clogging his long fingernails.

The white spots on the fingernails, which can appear as dots or lines, are called leukonychia.

Two years ago, the British National Health System adopted a "bare below the elbow" hospital dress policy that bans long fingernails, ties, hand and wrist jewelry — and, of course, lab coats.