The article presents the problem of particulate matter emissions into the atmosphere and their impact on the environment and human health. For the example of thermal modernized building, in which the improvement of thermal insulation of partitions and the exchange of coal boiler to a gas boiler was done, the opportunity to reduce emissions of particulate matter PM 2.5 and PM 10 is presented. The parameters of the energy performance of the building before and after thermal modernization are showed and also the impact of energy saving activities on the state of the environment is assessed.