An incident in Japan in the 1950s alerted the world to the potential problems of organic mercury in fish. Factories were discharging mercury into the waters of Minamata Bay, which also harbored a commercial fishing industry. Mercury was being bioaccumulated in the fish tissue and severe mercury poisoning occurred in many people who consumed the fish. ( ① ) The disabling neurological symptoms were subsequently called Minamata disease. ( ② ) Control over direct discharge of mercury from industrial operations is clearly needed for prevention. ( ③ ) However, it is now recognized that traces of mercury can appear in lakes far removed from any such industrial discharge. ( ④ ) Strictly controlled emission standards for such sources are needed to minimize this problem. ( ⑤ ) Fish advisories have been issued for many lakes in the United States; these recommend limits on the number of times per month particular species of fish should be consumed.

* postulate : 가정하다 ** incinerator: 소각로