The Upper Silesian basin belongs to the largest industrial pollution sources in Europe and the city of Ostrava ranks among the worst-polluted urban areas in the European Union. To assess temporal and spatial trends in atmospheric pollution, we determined concentrations of S, Pb, Cu, Zn, As, Cd, Sb, and Al in snow in downtown Ostrava and at the Lysa Hora Mt. (LH), situated 33 km southeast. Snowpack surfaces were sampled in February 2011/2012, 2018, and 2019. At LH, we collected snow samples at four elevations (700, 900, 1100, and 1300 m) in order to quantify mountain slope gradients in the pollution that, in turn, might reflect vertical stratification of air masses in a region frequently affected by temperature inversions. ²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁷Pb isotope ratios and back trajectories of air masses were used for pollution source apportionment. In year 1, there were clear-cut upslope decreases in concentrations of soluble pollutants. By year 3, the concentrations of soluble pollutants at LH decreased by 90% and the concentration gradients ceased to exist. Because annual precipitation totals at LH increase upslope by 75%, rates of deposition of soluble pollutants are now higher at the summit than those at the foot of the mountain. Hydrological control of deposition rates of soluble pollutants thus plays a more important role under lower pollution levels. Concentrations of soluble pollutants in Ostrava were up to 36 times higher compared with those at LH and also decreased by 90%. Lead isotopes indicated the continuing presence of gasoline Pb in the atmosphere, despite its ban in 2000.

中文翻译：

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俄斯特拉发地区（西里西亚上部，捷克-波兰边界）附近污染物和铅同位素比的山坡梯度的时间变化

西里西亚河上游流域属于欧洲最大的工业污染源，俄斯特拉发市是欧盟污染最严重的城市地区之一。为了评估大气污染的时空趋势，我们确定了俄斯特拉发市区和Lysa Hora山雪中的S，Pb，Cu，Zn，As，Cd，Sb和Al的浓度。（LH），位于东南33公里处。在2011/2012年2月，2018年和2019年2月对积雪表面进行了采样。在LH，我们收集了四个海拔高度（700、900、1100和1300 m）的积雪样本，以便量化污染中的山坡梯度，从而反过来可能反映了一个经常受温度反演影响的区域内空气团的垂直分层。²⁰⁶ Pb / ²⁰⁷ Pb和²⁰⁸ Pb /²⁰⁷铅的同位素比和空气团的后向轨迹被用于污染源的分配。在第一年，可溶性污染物的浓度明显上升。到第三年，LH的可溶性污染物浓度下降了90％，并且浓度梯度不再存在。由于LH的年降水总量使上坡增加了75％，因此山顶的可溶性污染物沉积速率现在比山脚下的要高。因此，在较低的污染水平下，对可溶污染物沉积速率的水文控制将发挥更重要的作用。俄斯特拉发的可溶污染物浓度比左手高出36倍，也降低了90％。铅同位素表明，尽管2000年禁止使用铅，但大气中仍存在汽油Pb。