The Chemistry of Precipitation in Forest Regions Under Anthropogenic Pressure

Atmospheric precipitation (rainwater, wet deposition) affected by industry is one of the sources of pollution that migrate to the ecosystem, especially by the uppermost soil layer and ground water. The chemistry of atmospheric precipitation around the ‘Miasteczko Śląskie’ zinc smelting plant (HCM) in the Upper Silesia region (southern Poland) was studied. The pH and chemistry of rainwater were analyzed with connection to the meteorological and climatic factors in the research area of the surrounded forest ecosystem area. Water samples were collected once per month (12 months in total) in 2021–2022 season at 20 monitoring points distributed in the grid (5 replications on each) located according to five modeled arches at the following distances from the main emission source: 1640, 2140, 2740, 3340, 3940 m. The control points were located opposite to the dominant wind direction (NW), and with wind directions in the distance above 6 km from the emitter. Pb, Zn, and Cd concentrations were found to exceed the Polish Environmental Protection Inspectorate reference data. Extremely high concentrations of pollutants were observed up to 3 km distance from the smelter: Cd (max. 1.43 mg L−1, mean 0.1) was higher, even than in the most polluted areas in the world (e.g., Mexico City), whereas zinc (max. 21.42 mg L−1, mean 1.71) and the Pb concentration (max. 0.44 mg L−1, mean 0.06) were similar to the highly polluted areas in the world. High concentrations of Cd, Zn, and Pb in rainwater indicate a strong industrial pressure in the adjacent forest ecosystem.