HYGIENIC REGULATION FOR JOINTLY ACTING HARMFUL FACTORS AND METHODOLOGY OF ITS EXPERIMENTAL RATIONALE

Abstract

With the combined action of agents, the toxic effect depends not only on the time and effects levels of each of them but also on the combinations in which these levels are located. The main problems in the experimental substantiation of hygienic regulations for this type of action are the determination of this dependence, the establishment with its help of safe combinations of exposure levels and their description. In the work methods of their solution are offered. This dependence is recommended to be obtained in the economical experiments proposed by the theory of mathematical planning. It is represented by a system of regression equations describing the dose dependencies observed at different moments after the onset of the impact (when indices are removed). In this case, the toxic effect is estimated by two indices, reflecting the degree of deviation of the state of the body of the experimental animals from the norm and the probability of this deviation. Effective and ineffective combinations are determined by this system of equations when substituting in them the values of the toxic effect corresponding to its presence or absence. In turn, hygienically safe combinations are determined by a system describing ineffective combinations of exposure levels that include stock coefficients that are reasonable for each agent. This system can be adopted as an experimentally valid hygiene regulation, which has the following advantages. It is determined by the results of the study of the joint rather than isolated action of agents, does not require the fulfillment of any conditions about the nature of this action (isoadditivity, etc.), and also takes into account not only the degree of deviation of the state of the organism of the experimental animals from the norm, but also the probability this deviation. In order to obtain the necessary information, we propose plans for experiments in which the number of groups of experimental animals is only one more than the number of cooperative agents. An example of the proposed approach is given.