
It Can Be An Issue
No-one really worried about the mercury in fish until the 1950s. That’s when thousands of people in Minamata, Japan, started experiencing health problems such as convulsions. When the birds and cats began displaying similar symptoms, it became clear that fish were the problem. It turns out they’d been contaminated by wastewater dumped at a chemical factory.
Attacking Their Bodies
The people who’d been poisoned had as much as 705mg/kg of mercury in their bodies, a stark contrast to the 4mg/kg that was considered average. Having so much of this substance in their systems meant their nerves and brains were being damaged.
It’s not fully understood how, but it’s believed it was attacking their myelin, the protective coating around their nerves. Other effects of mercury poisoning are thought to include cardiovascular disease and abnormal blood pressure.

Is It Safe Or Not?
What’s worrying about all this is that mercury is found in many kinds of fish. The level of it differs depending on the species, with swordfish and bluefin tuna a more significant risk compared to salmon, lobster, and squid. However, it’s prevalent in most aquatic life, meaning the dangers are always present.
Of course, if fish were so poisonous, people would have stopped eating them years ago. The reality is that as long as they’re not from polluted areas, they’re not going to cause you harm.
While you should always exercise caution with your food, we’d say you’re safe to keep eating fish.