An attempt was made to establish a concentration--time relationship for continuous and interrupted inhalation of a number of nonelectrolytes to establish norms for the permissible content of harmful substances in atmospheric air. The tests showed that the indicated relationship can be expressed in the form of a straight line on a logarithmic grid by using either acute toxicity parameters or the onset of physiological and biochemical shifts. This makes it possible to predict the chronic effect thresholds of substances on the basis of the results of short-term experiments.
The paper presents an overview of the main methodological approaches in experimental standardization of odorants (or mixtures of odorants) in the ambient air according to «obsessive» odor inadmissibility as a limiting criterion for justification of Maximum allowable concentration (MAC maximum one time dose) . It is shown that the developed procedure of establishing a permissible content of those substances is based on estimating the relationship «concentration – odor sensation probability of different intensity» (olfactory-odorimetry), using a common scoring of smell intensity and modern olfactometry equipment. Justified normative values are harmonized with international criteria for air quality including epidemiological studies-based levels established for odors with various qualitative characteristics. Their implementation will ensure the protection of the population from «obsessive» odor.
A short-time exposure on the concentration--time relationship base, a classification of substances according to the degree of hazard and the program for assessing safety coefficients have been suggested in order to predict the basic toxicometric parameters (chronic exposure thresholds, maximum allowable concentrations, safety coefficients, and others).
Introduction. Expansion of approaches to assessing the odour of substances polluting the atmospheric air, with the introduction of odorimetry (measuring the strength, intensity of odour) into practice indicates that the existing classification of the olfactory hazard of odorous components according to the “undefined” odour needs to be updated. Materials and methods. Experimental studies with the definition of a quantitative expression of the dependence of the likelihood of odour detection of different strengths on the concentration were carried out using the example of 13 mixtures of volatile organic substances on a dynamic olfactometer. The volume of olfacto-odorimetric studies was over 4600 measurements. Statistical data analysis was performed using the Probit Analysis computer program (v.4.0). Results. Based on the studies carried out, it was found that the lower the ratio of the concentration causing a 5% probability of detection of odour with a strength of 3 points (threshold of “offensiveness”, Limoff.) to the concentration causing a 50% probability of “undefined” odour (detection threshold or the threshold for an “indeterminate” odour, Limindef.), the more dangerous the substance is in relation to the development of an “offensive” odour. A new classification of the hazard of substances is proposed, taking into account the “offensiveness” of their odour: extremely offensive (Limoff./Limindef. ≤1.5), offensive (Limoff./Limindef. ≤3), moderately offensive (Limoff./Limindef. ≤6), slightly offensive (Limoff./Limindef. > 6). Limitations. This study is not without certain limitations, among which the main ones are the use of a relatively new method that requires additional testing; a relatively small number of study participants; methods for presenting odor stimuli and registering them. Conclusion. The ability of odorous substances to cause a feeling of “offensiveness” (“annoyance potential”), and, accordingly, their hazard class depends on the characteristics of the spectra of graph dependences of the probability of different strengths odour on the concentration on the probabilistic grid and the ratio of the parameters of the resulting dependencies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.