Week 6
  This topic I talk to about effect of chemistry. Chemistry is one of the field of science. So chemistry has influenced our day of life. Now chemical material is rapidly increasing. Human being has created 5 million substance. This fact indicate rapid development of chemistry. Now chemical substance is being　synthesized or separated per 2.6 seconds in the world. There are positive side and negative side in the effect of chemistry.
  Positive side is battery, chemical fertilizer and chemical seasoning. Battery is essential in our day of life. Battery is used in various category. For example, cell phone, car, iPad, electric dictionary and so on. And battery have possibility which improve our life. The possibility is fuel battery. Fuel battery do not harm environment. It only throws away water. Chemical fertilizer dramatically increased the harvest of agriculture. So chemical fertilizer saved many poor people. Chemical fertilizer include phosphorus (in chemical formula P), nitrogen (in chemical formula N) and potassium (in chemical formula K). The three material is thought as three element which is needed to grow agricultural products. Chemical fertilizer is sometimes said that it harms human's body. But it is not true. If you use chemical fertilizer appropriately, chemical fertilizer do not harm our body. Chemical seasoning also cause changes our food culture. Some substances are used as chemical seasoning. For example, glutamic acid, inosinic acid and guanylic acid and so on. These substance arouse our organ of flavor. Chemical seasoning improved quality of food which is cooked and sold in shop and foods cooked in home.

  Negative side is environmental pollution. In Japan, there are 4 big environmental pollution. First,  Minamata disease. This affair was caused by chemical company chisso in Kumamoto. This disease caused damaged people speech disorder, disequilibrium and hearing disorder and so on. And in the worst case the patient was dead. The cause of these symptom is methylmercury. The first patient found in 1953. But the disease was known to people and officially discovered in 1956. I think that this is too late to discover.  Second, second Minamata disease. This affair was caused by Showadenko in Niigata in 1965. The same symptom was admitted. It is said that this affair was caused by default of government. If government had acted properly to first minamata disease, second minamata disease would not have happened when first minamata disease was caused. Third, Itai-itai disease. This was caused in Toyama from 1910 to 1970. This is first Japanese environmental pollution. The cause of disease is cadmium. The symptom of this disease is weak and brittle bones. Fourth, Yokkaiti asthma. This was happened from 1960 to 1972 in Mie. The cause of material was sulfurous acid gas which was discharged from industrial complex. The gas which included cause of material was called "white smog. The symptom was asthma. And the worst case, the patient was dead. This disease had a possibility that cause heart attack and lung cancer. 
 I think if we did not use chemical substance appropriately, chemical substance would harm us greatly.