Heavy Metals in the Air and Snow Cover of Ulan Bator

Field observations have been used to characterize air pollution in Ulan Bator by heavy metals during the 2008/2009 heating season. The degree of technogenicity of emissions and their main sources are determined. The diurnal and seasonal dynamics of atmospheric pollution are considered. It is found that many pollutants exceed maximum permissible concentrations (MPC). The most dangerous components in the urban atmosphere include Pb (up to 26 mean daily maximum permissible concentrations (MPCmd) and airborne particles (up to 21 MPCmd). The study revealed very high levels of total air pollution, especially in the center of the city (air pollution index (API) > 50)). Soluble forms of heavy metals as contained in the snow are characterized by a maximally high degree of pollution hazard for the urban environment, with a low degree corresponding to solid-phase depositions. Snow cover pollution decreases as follows: yurt districts > industrial zone > multi-storey districts.