消毒饮用水既除病亦致病害命。1991年1月一艘中国货轮把被霍乱病菌污染的舱底污水倾倒在秘鲁的利马港。霍乱已经绝迹将近一个世纪的南美，在这一年年底又在秘鲁出现了30多万霍乱病例，而且疫情还蔓延到邻近国家。许多公共官员都把这次传染病的流行归咎于秘鲁的许多地区未用氯消 Disinfection of drinking water not only disease but also life-threatening disease. In January 1991, a Chinese freighter dumped bilge polluted by cholera germs into Peru’s Lima Port. Cholera has been extinct for nearly a century in South America. At the end of this year, more than 300,000 cholera cases occurred in Peru, and the epidemic spread to neighboring countries. Many public officials blame the epidemic on the unlicensed use of chlorine in many parts of Peru