Abstract

The objective of this study was to investigate the variations and correlations of the air pollutants during Covid-19 pandemic lock-down period for an industrialized city of Turkey. With this aim, air quality data measured at four different stations in the period March–June 2020 were used. Results of the study demonstrated that lock-down period caused significant decreases in pollution levels in urban, industrialized, and rural sites. In the city center (Station 2), reduction determined for PM10 and NO_x levels were 32.95% and 58.26%, respectively whereas in the industrialized site (Station 3) decrease ratios of these pollutants were 17.11% and 47.87%, respectively. Obtained reduction ratios may indicate that industrial and traffic activities have more significant contributions to NO_x emissions in the region. A strong positive correlation between CO and NO_x (r = 0.87) may also be evidence for traffic-related pollution in the city center while positively correlated NO_x and SO₂ levels indicate the importance of point sources for Stations 1 and 3. Coherent with the literature, O₃ emissions showed increasing tendency both in moderately industrialized (Station 1) and rural sites (Station 4). When average concentrations of the pollutants were compared for May 2019 and May 2020 periods, the most significant variation was noted for the industrialized region with 50.07% reduction in NO_x values.

摘要

本研究的目的是调查土耳其工业化城市 Covid-19 大流行封锁期间空气污染物的变化和相关性。为此，我们使用了 2020 年 3 月至 6 月期间在四个不同站点测量的空气质量数据。研究结果表明，封锁期导致城市、工业化和农村地区的污染水平显着下降。在市中心（2 号站），PM10 和 NO _x水平确定的减少量分别为 32.95% 和 58.26%，而在工业化场地（3 号站），这些污染物的减少率分别为 17.11% 和 47.87%。获得的减排率可能表明工业和交通活动对 NO _{x的贡献更大}该地区的排放量。CO 和 NO _x ( r  = 0.87) 之间的强正相关也可能是市中心交通相关污染的证据，而正相关的 NO _x和 SO ₂水平表明点源对于站 1 和 3 的重要性。与文献显示，O ₃排放在中等工业化（1号站）和农村地区（4号站）均呈上升趋势。当比较 2019 年 5 月和 2020 年 5 月期间的污染物平均浓度时，工业化地区的变化最为显着，NO _x值降低了 50.07%。