Developing methodical approaches to substantiating average annual maximum permissible concentrations of hazardous substances in ambient air in settlements as per acceptable health risk

A methodological basis for providing chemical safety for population is obtained via fixing safe concentrations of hazardous substances, including those in ambient air, as it allows absence of unacceptable risks for people’s life and health. In the Russian Federation average daily maximum permissible concentrations (MPC av.d.) are applied to prevent chronic effects on human health produced by hazardous substances that are present in ambient air. But in world practice it is conventional to apply average annual concentrations when assessing chronic exposure to hazardous substances as it allows applying existing acceptable health risks as assessment criteria. We propose an algorithm for substantiating average annual MPC of chemicals in ambient air as per health risks criteria; the algorithm is harmonized with international approaches and takes into accounts research results taken from previous research works that have been published in relevant scientific sources. The algorithm also involves accomplishing toxicological and/or epidemiologic examinations solely aimed at obtaining missing data. The proposed algorithm envisages selecting starting points for substantiating a hygienic standard and uncertainty factors. Proposed methodical approaches have a distinctive feature that is verification of obtained standards as per acceptable (permissible) carcinogenic risk criteria and assessment of safety under exposure equal to MPC av.an. during the whole life span. Development and implementation of average annual maximum permissible concentrations of hazardous substances in ambient air will promote harmonization of the domestic regulatory base with hygienic standards and norms accepted in world practice.