A test of groundwater at the newly constructed Toyosu Fish Market in Tokyo showed benzene, arsenic and cyanogen at levels exceeding government safety limits.
Japan’s environmental regulations stipulate that levels of benzene exceeding 0.01 milligrams per liter of groundwater are unsafe. It was found in 35 locations at the site, with a maximum of 0.79 mg. Arsenic, with the same limit, was found in 20 locations, with a maximum reading of 0.038 mg. Cyanogen, for which there is zero tolerance, was found in 39 locations, with a maximum of 1.2 mg.
Benzene is a natural constituent of crude oil. Benzene increases risk of cancer and other illnesses, and is a cause of bone marrow failure. Most people are exposed to small amounts of benzene from indoor cigarette smoke, exhaust fumes from built-in home garages entering the house, from glues and other chemicals in construction materials (sick house syndrome), and from living near a gas station.
Arsenic is both a poison and a carcinogen. Cyanogen gas is an irritant to the eyes and respiratory system. Inhalation can lead to headache, dizziness, rapid pulse, nausea, vomiting, loss of consciousness, convulsions and death. It readily undergoes reduction to cyanide.
This was the ninth in a series of groundwater tests at the contaminated brownfield site, formerly occupied by a Tokyo Gas Co. factory.
Before clean-up was completed in October of 2014, the level of benzene was 43,000 times above the standard and cyanogen was 860 times above the standards, with arsenic, mercury and cadmium also discovered in high levels on site. The clean-up was supposed to include a thick layer of fresh soil over the whole site, but – contrary to the recommendation of an expert panel – areas under the buildings were skipped and basements were constructed instead to house equipment for treating water from monitoring wells.
In the first seven surveys after remediation, levels remained within the safety standards. In the eighth test, results of which were released in September last year, levels from 1.1 to 1.9 times the maximum levels for benzene and arsenic were detected. This led new Tokyo Governor Yuriko Koike, who took office in August 2016, to delay the planned November move until all testing was complete.
When the test results were revealed, one expert, Kohei Urano, a professor emeritus of environmental safety at Yokohama National University, said there were no safety issues, and it would only pose a hazard if fish were washed in the groundwater.
However, groundwater will not be utilized at the market. According to experts who have studied the issue, the danger is mainly that the groundwater could reach the surface where the chemicals could convert to a gaseous form, which would then be inhaled by the workers. The fish, being for the most part dead, and also being in the market for a short time, would not incur much ingestion of the dangerous chemicals.
The latest test will be repeated, with new samples sent to several labs for verification. Experts have explained the previous large deviation from earlier tests by pointing at possible contamination of the samples with bits of soil. The higher levels may also have something to do with the pumping and treatment of groundwater, which began before the latest test.
However, there have been claims that city government falsified the previous test results, with the resulting loss of public trust designed to doom the new market. Hence, the decision to send the new samples to a variety of labs to ascertain the accuracy of the results.
Hiroyasu Ito, chairman of the Tsukiji Market Association, has been asking Gov. Koike to decide quickly whether the market should be moved. Many of the vendors have invested in cold storage facilities in the new market buildings and have hired additional staff. They are paying rent on the space, equipment lease charges, and increased payroll and are expecting the Tokyo government to compensate them for losses in case of further delays or cancellation.
The main opposition to the move has been from the Tokyo Central Market labor union, headed by Secretary-General Makoto Nakazawa, and from the Consumers Union of Japan. Both have called for scrapping the planned move completely.
In addition to the pollution issue, the move will leave the Outer Market, consisting of retailers and restaurants, disconnected from the auction and intermediate wholesalers (Inner Market). This may cause a decline in tourism to the area, and a loss of business to the operators.
