上海市每天有数千吨污水流入各大小河浜,最后汇集于黄浦江,所以黄浦江的水是受到严重污染的。从这种水里可以检查到多种致病菌(特别是肠道致病菌)。1957年6月底到7月初,上海市划船俱乐部曾在龙华附近举办了一次横渡黄浦江的游泳竞赛,参加者—千余人。龙华虽位近黄浦江之上游,但涨潮时江水可以倒流。本调查的目的就是要了解参加这次游泳竞赛 There are thousands of tons of sewage flowing into major rivers and streams every day in Shanghai, and the water is finally collected in the Huangpu River. Therefore, the water in the Huangpu River is seriously polluted. From this water can be checked to a variety of pathogens (especially gut pathogens). From the end of June 1957 to the beginning of July, the Shanghai Boating Club held a swimming competition across the Huangpu River near Longhua. More than 1,000 participants took part. Longhua though near the upper reaches of the Huangpu River, but when the tide can be reversed. The purpose of this survey is to understand how to participate in this swimming competition