Scientific substantiation of priority chemicals, objects for setting quotas and trends in mitigating airborne public health risks within activities performed by the sanitary service of the Russian Federation

The study was conducted due to the necessity to streamline management of ambient air quality in large industrial cities in the country. The relevant tasks were set within the ‘Clean Air’ Federal project and the system for setting emission quotas. The aim was to develop scientific-methodical approaches that would support Rospotrebnadzor in performing its functions and duties as regards management of ambient air quality, including those accomplished within the ‘Clean Air’ Federal project. We took into account that initial data for the whole system for setting emission quotas were represented by aggregated calculation of pollutant dispersion. The study relied on input and output data provided by the ‘Ekolog-Gorod’ software package for calculating ambient air pollution. This software employs methods for calculating emission diffusion in ambient air that are applied as standards in Russia. Calculations were accomplished at points located within residential areas in the analyzed cities and covered not less than 20 major contributions made by emission sources to levels of each chemical at each calculation point. Airborne health risks were assessed in accordance with the valid methodical documents. We applied the following criteria for permissible (acceptable) risks: carcinogenic ones should not exceed 1.0·10-4; non-carcinogenic chronic and / or acute risks should be at a level of a hazard index for chemicals with the same effects equal to 3.0. The brunch and bound method of linear programming was applied to substantiate optimal regulatory impacts aimed at minimizing health risks by reducing emissions into ambient air. We developed a fundamental algorithm for identifying a list of priority pollutants and a list of objects for setting emission quotas, as well as for substantiating optimal regulatory impacts to mitigate airborne public health risks. We suggest ranking chemicals as priority pollutants in case their registered levels are higher than the established hygienic standards and they in total account for not less 95 % of contributions to unacceptable health risks for critical organs and systems at least at one calculation point. Priority objects are those that are responsible for not less than 95 % of unacceptable health risks and violations of the established hygienic standards. The study describes a developed and tested instrument for selecting optimal regulatory impacts as per relevant hygienic indicators, including levels of public health risks. The suggested approaches support the Sanitary Service in its effort to provide proper quality of ambient air. They make it possible to identify priority chemicals and objects for setting emission quotas on the unified methodical basis for any city on the country, including those listed within the ‘Clear Air’ Federal project as priority ones. They also allow estimating whether environmental protection activities are relevant to the essence and levels of public health risks.