FIELD: analyzing or investigating materials. ^ SUBSTANCE: method comprises determining actual concentrations of substances containing in the contamination sources, classifying the substance as contaminated ones when their concentration exceeds a permissible value, calculating the contamination from a single source, determining total contamination by summarizing the values of toxic hazard for each phase condition of the environment and for the totality of fluids. ^ EFFECT: enhanced reliability. ^ 3 cl, 1 tbl