Problems of outdoor air quality hygienic assessment in the cities of the leningrad region

Introduction. The evaluation of the contribution of enterprises to the formation of levels of air pollution and the directly associated public health risk is of particular relevance during the hygienic assessment of outdoor air quality in populated areas. In this case, the results of computer simulation of concentrations in atmospheric air in many cases differ significantly from the results of field studies (monitoring), which can lead to a significant distortion of the expected risk levels. In this regard, the stage of exposure (impact) assessment as one of the problematic stages of the risk assessment for public health can be considered.

Material and methods. The object of the study was the level of air pollution in industrialized cities of the Leningrad Region - Vyborg, Kirishi, Tikhvin, Gatchina. There was delivered a list of priority enterprises-sources of air pollution in the studied cities, from the emissions of which the average annual air concentrations in populated areas were modeled. To assess the actual air pollution, the results of field studies (monitoring) for the period 2015-2017 were analyzed. Based on the results of the calculation of air pollution and field data, the calculation of chronic non-carcinogenic and carcinogenic risks to public health was performed.

Results. In all the cities studied, no exceeding the permissible values of risk was found on the basis of calculated average annual values of pollutants generated from the emissions of enterprises. At the same time, similar calculations of risk, made on the basis of actual concentrations of pollutants in the atmospheric air, according to long-term monitoring data, showed significantly higher values. The highest risk values, taking into account field data on the background level of atmospheric pollution, are typical for the cities of Kirishi and Vyborg, where the list of controlled pollutants is wider, due to including iron, cadmium, manganese and copper. These air pollutants can be considered a priority for the cities studied because of the unacceptably high level of non-carcinogenic risk caused by them.

Conclusion. Unacceptably high levels of non-carcinogenic risk from background air pollution in the cities of Kirishi and Vyborg are due to iron, cadmium, and copper, which are practically absent in the emission structure of enterprises in these cities. It may be due, on the one hand, to insufficient consideration of the contribution of all potential sources (including motor transport), and on the other hand, to be a consequence of the inaccuracy of laboratory research techniques. It is advisable to pay attention to the problem of organizing the monitoring of air quality in populated areas, including with the above pollutants.