Minmata Disease Case Study

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4.0 Strategies That Have Been Taken To Reduce or Eliminate the Minimata Disease The Japanese government has taken several strategies to reduce and eliminate the Minamata disease. The strategies taken are as follows: 4.1 Dredging of Contaminated Bottom Sediment The Japanese government has taken proactive acts by dredging of the contaminated bottom sediment in the area of the Minamata bay, the Marushima Fishing Port and the Marushima-Hyakken Canal with the cost was paid by Chisso, Niigata Prefecture, the national government and the Kumamoto Prefectural Government. This action was taken due to the residual presence of mercury in the substratum of nearby waters could still cause the contamination of water and marine lives, even though the discharge…show more content…
However, due to the improvement of the marine environment, the dividing nets were removed in 1997 based on the levels of mercury for seven species of fish were below the provisional control values for three consecutive years. This strategy was able to prevent the spread of contaminated fish, calm social panic and stabilize the drastic falling of fish prices. 4.2.2 Restrictions on Fishing The restriction on fishing inside the Minamata Bay was implemented and intermittently continued until October 1997 when the dividing nets in Minamata Bay were completely removed. The restriction on fishing is a brilliant strategy to reduce or eliminate Minamata disease because the residents in the Minamata Bay area will directly be avoided from eating fishes from the the area which in turn able to eliminate Minamata disease occurrence. 4.3 Changing State of Pollution Situation The Japanese government also continuously monitored water quality, sediments, and fish in Minamata Bay and the Agano River on a regular basis to ensure that the environment is maintained in a satisfactory state. The results from this strategy enable the water quality meets the environmental quality standard values which in turn enable the water environment to return to its original…show more content…
From Ministry of Environment, Japan 4.4.1 Material flow of mercury Japan has drawn up the material flow chart of Mercury to clarify a flow of mercury in human society, such as mercury use in production activities and discharge into the environment including air, water and soil. The data is beneficial in informing the government about Japan's mercury supply and demand which enable them to plan specifically on how to reduce the mercury usage amount. Figure 9 Material flow of mercury Note. From Ministry of Environment, Japan 4.4.2 Mercury Demand Reduction and Halt of Primary Mercury Mining Apart from that, Japan also introduced restrictions on mercury discharge causing the use and discharge of mercury in the country to decline. This strategy is able to totally eliminate the Minamata disease because many factories had introduced new technologies which is mercury free alternatives, thus reduce mercury demand drastically. 4.4.3 Reduction of mercury use in manufacturing processes Japan has adopted mercury-free production methods in manufacturing processes including the manufacturing of caustic soda and chlorine as well as vinyl chloride monomer and acetaldehyde. When the usage of mercury reduce in the manufacturing process, thus, the discharge from the process is getting safer and enable Minamata disease to be eliminated

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