[Environmental study on toxicity of water resulting from pesticide and biocide pollution].

A chemical product has a level of danger or security which depends on the concentration and on the exposure time. The toxicity of the water is established by the answer (survival) of an animal organism in contact with a specific chemical product in short time. There are several reliable methods in the world; in any case the most significant aspect is given by the mortal concentration of the substance (mg/L) in connection with the organism dimensions. Among the methods we can point out:--% of mortality;--N.O.E.L. (No Observed Effect Level);--LC50. We must know the following data too:--responsable for the product;--registration of the pesticide/biocide;--risk valuation;--T.E.R. (Toxicity Exposure Ratio);--P.E.C. (Predicted Environmental Concentration); measures of detoxication;--ratio product toxicity/usage. The chronic effects concern the health the growth, the survival and the reproduction. These data are used for the management of the risk, the preparation of chemical substance in security, the treatment of accidental poisoning, the determination of TLV and safety level (LD50-LC50) of the substances (pesticide, biocide).