Toyosu groundwater tainted by benzene 100 times over safety limit, plus arsenic: survey

JIJI, Staff Report

Groundwater at the replacement site for world famous Tsukiji fish market contains benzene levels 100 times over the safety limit, the Tokyo Metropolitan Government said in announcing the results of its 10th survey at Toyosu.

Samples also revealed the presence of arsenic, another carcinogen, as well as cyanogen, a precursor to cyanide banned by environmental standards, metropolitan officials said Sunday.

The water survey was conducted at Tsukiji’s planned replacement site in the Toyosu district in Koto Ward between late January and early this month.

The highest benzene reading in the latest survey exceeded the reading in the previous survey by 79 times, while the arsenic levels were found to be 3.6 times over the safety limit.

The cyanogen was found in 18 of the 23 spots surveyed.

Tokyo Gov. Yuriko Koike said the latest findings need to be taken seriously but did not say whether the market would open as planned. She only said that “a comprehensive decision will be made” after the results are examined by a panel of experts.

The market was built to replace the aging Tsukiji wholesale food market in Chuo Ward, but Koike put the plan on hold soon after taking office last summer after learning of new soil pollution concerns at a new site. The Toyosu site was previously home to a gas plant, and a previous administration headed by nationalist Gov. Shintaro Ishihara had promised to implement safeguards and remediation efforts to persuade a skeptical public to accept the ¥588 billion project.

Sunday’s findings were reported at a meeting of a panel commissioned by the metropolitan government to discuss soil pollution control at the site. The panel said the results apparently reflect a change in the flow of groundwater a new water management system was switched on in October.

Tatemasa Hirata, chairman of the panel, said at a news conference after the meeting that the environment above ground is safe.

Toxic chemicals underground can be controlled if appropriate measures are taken, claimed Hirata, who is also chief of the Open University of Japan’s Wakayama Study Center.

The latest survey, the 10th of its kind, was carried out after the ninth survey from late November to early December showed much higher levels of toxic substances than were recorded in the preceding eight surveys.

A different sampling method was used in the ninth survey, and the panel concluded the results of all of the surveys were valid. The surveys started in 2014.