Sanitary Assessment of Hazardous Materials Exposed To Highly Toxic Chemical Compounds

Industrial or terroristic accidents in which toxic chemicals (TC) are the main or attendant damaging factors should be regarded as a new challenge for experts, because of little knowledge on the methodology to estimating the long-term risk for humans due to contamination of the building materials and environment. In the Russian Federation, there appeared to be a kind of model systems for developing an algorithm for solving these or similar problems. Under dismantling and liquidation of the former facilities for chemical weapon production (FCWP) the building materials are regarded as potential waste products the fate of which (processing, warehousing, utilization, and destruction) is dependent on their possible hazard for human population and environment. The standard approaches for hazard assessment of waste products of the FCWP turned out to be insufficient. When conducting the present work, the following problems have been solved: 1. Selection of representative samples taking into consideration a diversity of construction materials, great quantities of potentially toxic waste materials, information on the production conditions, breakdowns in the process of production, accidents, composition of the decontaminators used, decontamination frequency, etc. 2. Analysis of TC in composite matrixes complicated by the following problems: extraction, masking effects of concomitant components during indirect analysis, lack of certified methods of direct analysis of TC, discrepancy of results of GC and direct GCMS analysis, low sensitivity of GCMS analysis, big volume of samples (more than 0.5 kg), heterogeneity of physical-chemical properties of different matrixes influencing the process of degradation of TC. 3. Hazard assessment of the wastes in toxic-and-sanitary experiment relying on non-specific signs of intoxication due to relatively low percentage of TC and masking effects of various matrix components. Application of the integral toxicity tests with soil-and-plant microflora and hydrocoles. 4. Development of non-standard methodical approaches when determining and interpreting the hazard classes of the wastes, containing high toxic compounds such as nerve gases. In particular, disembodied methods applied for solving the tasks of assessment of chemical compounds toxicity were summarized, as well as a uniform scheme of experimental toxicological assessment of TC of a high risk is presented. A system of quantitative assessment of the TC risk is developed on the basis of integral coefficient of risk (KTC), thus simplifying decision making after toxicological testing. Calculation of the coefficient of the TC risk is based on logarithm of ratio of toxicometry parameters to the value of identical parameters determining affiliation of the TC to the 1st class of risk (extreme risk). Due to the methodology developed in our Institute, we have for the first time estimated the class of toxicity of a highly complicated industrial system. (author)