Hexavalent chromium pollution caused by dumped chromium slag at the urban park in Tokyo

Abstract

In January 2013, a high concentration of hexavalent chromium was detected in the meltwater at an urban park in Tokyo. A chromate manufacturing plant operated at this location until 1972. The highest concentration value showed was in excess of up to 740 times the Japanese regulation value (0.05 mg L−1). Although 40 years have passed since dumping, highly polluted groundwater is still found today. Heavy rain or snowfall is a trigger for the outbreak of Cr(VI) pollution in this area.