According to the Okinawa Times newspaper, 0.275mg of toxic hexavalent chromium, which is more than five times the 0.05mg (per litre) limit set by the Japanese environmental standard, has been detected at the construction site of the new 10,000-capacity Okinawa Arena.
Hexavalent chromium is a type of heavy metal mainly used as an oxidant, and is known to cause lung cancer among other medical conditions if it stays inside the human body for a prolonged period of time.
The City of Okinawa, which is building the arena, conducted a soil investigation and the report that emerged points to the waste placed above the location where the test sample in question was collected, saying that “the corrosion of the metal products which contained cement waste and chrome” resulted in the excess amount of hexavalent chromium detected.
According to the city, a number of construction works have been carried out to provide roads, a rainwater drainage system and a parking lot when the site was used as a bullring. The city plans to conduct a water survey to further investigate how the previous works have affected the site.
Professor Yutaka Tashiro, Environmental Science, Meio University, said: “How far hexavalent chromium has contaminated the area must be found out in full, and purification measures must be taken.”
Okinawa Arena is scheduled to open in September 2020. The facility will serve as the home of the Ryukyu Golden Kings basketball team.
Image: City of Okinawa
News provided by The Stadium Hub