[Someone]

All over half a century ago, but there are https://en.wikipedia.org/wiki/Four_Big_Pollution_Diseases_of..., cases where the Japanese government didn’t come out well (e.g. Itai-Itai disease was known in 1912, but according to Wikipedia, “Medical tests started in the 1940s and 1950s”, and for Minamata disease “The Kumamoto and Kagoshima prefectural governments conducted a joint survey in late 1960 and early 1961 into the level of mercury in the hair of people living around the Shiranui Sea. The results confirmed that organic mercury had spread all around the inland sea and that people were still being poisoned by contaminated fish. Hundreds of people were discovered to have levels greater than 50 ppm of mercury in their hair, the level at which people are likely to experience nerve damage. The highest result recorded was that of a woman from Goshonoura island who had 920 ppm in her sample.

The prefectural governments did not publish the results and did nothing in response to these surveys. The participants who had donated hair samples were not informed of their result, even when they requested it”