PM2.5 field in the air of Družec village during heating season

Residential heating by solid fuel combustion in small settlements has great potential to degrade air quality, especially PM2.5 emissions, during the winter heating season, to such an extent, that WHO and US-EPA limits for PM2.5 are frequently exceeded. There were found significant temporal variability and spatial heterogeneity of the PM2.5 concentration field. 24h limit for PM2.5 (US-EPA, 35 μg∙m-3) using a stationary network of 6 monitors measuring minute concentration of PM2.5, In the village Družec, Kladno district, during the 14-day measuring campaign. Campaign average exceeded the limit at the primary school garden. In the other sites, the limit was usually exceeded occasionally except one day, when the limit exceedance was recorded in all the sites as well at the whole area of the Czech Republic. The analysis of time course of minute values of PM2.5 shows that the residential heating increased PM2.5 concentrations on average by 61-72% (16-25 g∙m-3) or 40-49% (6-10 g∙m-3) at exposed or background sites respectively; PM2.5 values decreased exponentially with wind speed up to 2 m∙s-1, when they stabilized at 8-16 g∙m-3. At the microscale of the village, there were also found spatial and temporal heterogeneity of PM2.5 and aerosol particle concentrations PNC using by mobile measurement of PNC..