Taiji, Wakayama Prefecture, has taken hair samples of residents to determine how much methyl mercury is in their bodies from dolphin meat they have eaten linked to the town's contentious annual slaughter of the mammals.

An official of Taiji's Resident Welfare Division told The Japan Times on Wednesday that the town of some 3,500 people took hair samples from those who went in for regular health checkups and agreed to submit them for testing between June and August.

It is the first time the town has tested hair samples to determine levels of the highly toxic substance. The test results are expected to be in by the end of March.