Environ Exp Biol (2017) 15: 143–150

Assessment of atmospheric pollution with heavy metals and nitrogen using Pleurozium schreberi mosses as bioindicator in Latvia: spatial and temporal aspects

Abstract

Concentrations of eight metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn and V) and nitrogen were determined during a nation-wide biomonitoring survey using Pleurozium schreberi moss in Latvia. Particular concentrations of heavy metals were clearly associated with local emission point sources in Liepāja (Cd, Cr, Cu, Fe, Pb, V, Zn), Brocēni (Ni), Riga (Cr, Cu) and Daugavpils (Cr, Cu, Fe, Ni, Zn). Increased concentrations in the western part of Latvia (Cd, Cr, Cu, Ni, Pb, V, Zn) were due to the long-range transboundary transport of pollution from Europe and local metallurgical and other factories sources in Liepāja City. Higher concentrations near the Lithuanian border were associated with the impact of pollution from the cement industry of Naujoji Akmene (Cu, Fe, Ni) and the oil refinery of Mažeikiai (Ni, V). In general, concentrations of heavy metals were lower in Latvia compared to the background levels in Europe. In comparison to the previous monitoring results, the concentration of heavy metals in moss has decreased in Latvia. The higher N concentrations in the south-western part of Latvia were due to the long-range transboundary transport of pollution, territories with intensive agriculture and areas close to the industrial cities.