Dioxin concentrations up to 16 times above national safety guidelines were detected in soil in Tokyo's Ota Ward, making it the nation's second-worst dioxin contamination in a public place, Tokyo metropolitan government officials revealed Wednesday.
The dioxin -- a suspected endocrine disrupter -- was found in soil underneath a paved municipal road in an industrialized area of the ward, located in southern Tokyo, earlier this year.
At one point surveyed, 16,000 picograms of dioxin per gram of soil was detected. The government's accepted limit for dioxin in soil is 1,000 picograms per gram. A picogram is one-trillionth of a gram.