TAIJI, Wakayama Pref. — Researchers have found extremely high methyl mercury concentrations in the hair of some residents of Taiji, Wakayama Prefecture, where people have a tradition of eating whale and dolphin, but none have developed any related illnesses.

The researchers said Sunday that of 1,137 residents tested, the methyl mercury density in 43 exceeded the level recognized by the World Health Organization as capable of causing neurological damage. The tests covered roughly a third of the town's residents.

Experts were at a loss to explain why none of Taiji's residents have mercury-related health problems.