Which of the following water pollutants causes Minamata disease?

Minamata disease is a severe neurological disorder caused by the consumption of fish and shellfish contaminated with methyl mercury, a highly toxic form of mercury. The disease was first identified in the 1950s in Minamata Bay, Japan, where industrial wastewater from a chemical factory had polluted the surrounding waters with methyl mercury. Local residents who relied on seafood from the bay began developing symptoms of mercury poisoning, giving the disease its name.

Methyl mercury (CH₃Hg) is an organic compound formed when mercury in the environment is converted by microorganisms in water bodies. Once produced, it enters the aquatic food chain, accumulating in small aquatic organisms and then concentrating progressively in larger predators through a process called biomagnification. Humans consuming contaminated fish receive dangerously high doses of mercury, which primarily damages the nervous system.

Symptoms of Minamata disease include numbness in hands and feet, muscle weakness, loss of vision and hearing, difficulty speaking, and in severe cases, paralysis or death. Pregnant women exposed to methyl mercury can also pass it to their unborn children, causing developmental disorders and birth defects.

Lead and perchlorate are also environmental pollutants but do not cause Minamata disease. Salmonella, on the other hand, is a bacterium responsible for foodborne illness, not chemical poisoning. Methyl mercury’s unique toxicity makes it one of the most studied environmental contaminants.

Understanding Minamata disease highlights the importance of environmental monitoring, industrial waste management, and water pollution control. It remains a classic example of how toxic chemicals can move through ecosystems and affect human health. The incident led to global awareness about mercury pollution and stricter environmental protection laws worldwide.