Industrial toxic pollution of marine waters - the Minamata Case

Abstract

Industrial toxic pollution of seawater poses a risk to the lives and health of the local population. Accumulation of toxic chemicals in the food chain can seriously harm not only people in the area but also their generations. Minamata disease is a typical example of harm caused to people by environmental pollution. Literature on industrial toxic pollution of marine waters and the subsequent health problems has been collected and analyzed. Monographs, articles in Bulgarian and foreign scientific journals, and other literature sources on methylmercury pollution found out in Minamata Bay, Kumamoto Prefecture, Japan, have been investigated and summarized. Minamata disease is a methylmercury poisoning with neurological symptoms due to the daily consumption of fish, seafood and seaweed obtained from Japan`s highly toxic, polluted area. Two outbreaks of the disease have been observed. Conclusions have been drawn that methylmercury (a by-product of the production of acetaldehyde discharged by the wastewater of chemical plants) accumulates in the marine inhabitants` food chain causing Minamata disease. It has not only a medical aspect but also a social and economic one. Identifying the cause of the disease leads to serious measures being taken in Japan to protect the environment and the health of the population. Chemical enterprises are closed and the victims are paid benefits. Millions of dollars have been invested to eradicate the accumulated methylmercury in the sediments of the Shiranui Sea. Establishing the link between the consumption of mercury-contaminated foods and Minamata disease lead to significant legislative changes in Japan and later in the whole world.