Mercury poisoning

Mercury poisoning is a health disturbance caused by high levels of exposure to mercury.

Symptoms of mercury poisoning include pink colour in the cheeks, fingertips, and toes, swelling, unexplainable sweating, lots of saliva, fast heartbeat (tachycardia), high blood pressure (hypertension) and hair loss for some people. Mercury exposure happens most often through eating certain types of fish or via other ways.

The nasty property of mercury is that it accumulates (that is: piles up) in the food chain. A famous case of mass mercury poisoning is the Minamata case in Japan. Minamata is a fishing town at Kyushu island, Japan, and there was a chemical factory whose process used mercury. Some of the mercury went to waste water and in the sea. The algae (small water plants) absorbed the mercury, which were in turn eaten by small fish, and the small fish were eaten by bigger fish, which were then caught by the fishermen. The poisoning was first detected on the town cats, which ate the fish the fishermen had caught. The animal effects were severe enough in cats that they came to be named as having "dancing cat fever." But in the end the same happened to humans too as the fishermen and their families ate the same fish. The mercury had accumulated in the food chain and in the end poisoned the apex predators (cats and humans). The poisoning and resulting deaths of both humans and animals continued for 36 years, while the company and the Kumamoto prefectural government did little to prevent the epidemic. In the end the epidemic was discovered and reported, the factory was sentenced to pay repairments to the people, and it changed the process into one where mercury was no more used. There have been no new poisonings after 1968 in Minamata.