was it hg?

An excerpt:

Minamata is a small industrial and fishing town on the west coast of Japan’s southernmost main island, Kyushu. Minamata, home to some twenty-five thousand people, still harbors a population of roughly six hundred people who still suffer the irreversible effects of what has come to be known as Minamata disease.

Shortly before the outbreak of the First World War, the Chisso Corporation, still in existence today, though under a slightly different name, established a factory in Minamata. A dizzying array of chemicals and fertilizers were produced at the Chisso plant, which spewed an equally astonishing and complex mélange of waste products into the area’s waterways. Among this pot-pourri of effluence was methylmercury, a disastrously hazardous byproduct in even the tiniest amounts — and Chisso was not dumping out tiny amounts. In Minamata Sea, the first animals to accumulate mercury in their bodies were shellfish. Then, up the food chain the mercury went, unable to be expelled, gathering in ever-increasing deposits, passing from animal to animal to animal to human, in a process known as bioaccumulation. For the next several decades, toxicity levels in Minamata Bay rose astronomically, and may well have continued to do beyond the middle of the twentieth century, were it not for some very sick people, and a few oddly-behaving cats.

From the 1930s through the late 1960s, the Chisso Corporation jettisoned so much mercury into Kyushu’s waters that almost every living creature in the Minamata area was impacted on some level. The effects were horrifying. By the 1950s, signs had begun to emerge that nothing short of a major disaster was afoot. Fish populations in the bay decreased significantly, some estimates claim by as much as 90%. Besides Chisso itself, which was Minamata’s largest employer, the seafood industry was the most important source of income for the town. With so large a percentage of the population dependent on fish as a dietary staple, and on the fishing industry as a whole for income, the rapid decline in fish populations had an immediate and devastating impact on the local economy. It was apparent, long before the first diagnosis of the neurological disease in humans, that Chisso’s polluting of the waterways in and around Minamata was to blame for the problems seen in animals: in fact, Chisso paid out, sporadically over the course of several years, several nominal payments of “sympathy” money to communities impacted by their wastewater.

From there, things got much, much worse.

Twisted Fingers, Twisted Minds

Strange animal behavior rang the first alarm bells. People in the town began to notice peculiar conduct in household pets and other small animals such as rodents. Inexplicably, dogs and cats would suddenly convulse into fits of spasms, often ending in death or severe brain damage. Some cats were obser

ved leaping into the sea, as if of their own suicidal will, a phenomenon widespread enough to have attracted its own nickname. The condition came to be known as “cat dancing disease”, but by the time the cute moniker had been given to cat behavior, the impact to humans was already profoundly devastating. People experienced a rapid decline in muscle strength, vision, hearing, and speech. Contortions and convulsions abounded: images of twisted fingers, spasmodically-bent wrists at sharp angles to rail-thin arms began to circulate in news media around the world, and would, some decades later, be used as propaganda tools...