Determination of the pond silt is very important for study of water pollution.In this paper the relation of pond silt pollution to mortality of liver cancer was studied. The experimental results indicated that the matters which induce distortion of chromosome are present in pond silt in the areas of high liver cancer incidence.The tendency of Tradescantia micronucleus frequency induced by these matters in sampling regions agrees with that of 11 years liver cancers mortality of residents that provided experi...