[Contaminative conditions evaluation of sixteen main rivers flowing into sea around Bohai Sea, in summer of 2005].

In order to study the pollution conditions of sixteen main rivers around Bohai Sea such as Yellow River and so on, water samples were collected synchronously from July 1 to July 5 in summer of 2005. The results show that, thirteen rivers are worse than the IV water, and eight rivers such as Ziyaxinhe River and so on are worse than the V water. By analysing the sharing ratio of pollution, the key pollutant is petroleum (eleven rivers), the second is nutrients, and the third is permanganate index.