The thyroids of young Fukushima residents aren’t significantly different from their counterparts’ glands in three prefectures spread across the archipelago, a survey by the Environment Ministry says.

The study, conducted from last November to March, examined 4,365 residents between age 3 and 18 in the cities of Hirosaki, Aomori Prefecture, Kofu in Yamanashi Prefecture and Nagasaki. It concluded that the number of small lumps and other anomalies detected in their thyroids were “almost equal to or slightly lower in Fukushima.”

The thyroids of 69.4 percent of those in Kofu had lumps less than 5 mm wide or cysts smaller than 20 mm, followed by 57.6 percent of the subjects in Hirosaki and 42.5 percent in Nagasaki.

In Fukushima Prefecture, home of the 2011 nuclear crisis, thyroid tests on about 360,000 residents under 18 found lumps and other issues in 41.2 percent of those examined after the disaster.

Shunichi Yamashita, vice president of Fukushima Medical University, said the latest survey underscored the fact that “small cysts and lumps naturally exist in children when they are examined with the same level of precision as in Fukushima.”