Review of methodological approaches to odor determination in ambient air

The presence of odorous pollutants in the atmospheric air is increasingly considered as a significant environmental and sanitary problem, since persistent odors contribute to an increase in the number of complaints and negatively affect the comfort of life of the population, however, direct measurement of concentrations of individual substances often does not reliably assess the strength of the odor. The lack of a unified regulatory system in Russia makes the problem particularly relevant, which leads to the use of disparate and not always quantitative control methods. The purpose of the work is to generalize and compare the existing approaches to the definition of odors used in Russia and abroad. The article discusses in detail three main groups of methods. Instrumental methods such as gas chromatography-mass spectrometry provide accurate identification of the chemical composition, but do not reflect the subjective perception of odor by humans and are often unable to detect ultra-low concentrations of odorants. Sensory methods, the key of which is olfactometry, directly measure the threshold of olfactory perception, providing a quantitative assessment in units of smell (EC/m3), however, they are subjective, time-consuming and require the involvement of trained experts. Promising sensor systems, the so-called «electronic noses», allow for real-time operational monitoring, but so far they suffer from instability and the need for complex calibration. Auxiliary approaches, including bioindication and variance modeling, complement the overall picture, but do not provide direct quantitative estimates. The analysis demonstrates that none of the methods is universal. As the main conclusion, the authors emphasize the need for an integrated approach that integrates instrumental, sensory methods and modeling to obtain a reliable assessment of odor pollution. In the future, the development of technologies, including the use of artificial intelligence, and the formation of an adequate regulatory framework in Russia will make it possible to effectively address the challenges of controlling and reducing the impact of unpleasant odors on the population.