A comparison of mobile and stationary air quality measurements in Lublin, Poland during the COVID-19 lockdown in 2020 and in a comparable period in 2017 has demonstrated that a substantial decrease of the traffic intensity by more than 50%, especially during certain times of the day in the lockdown period has only been partially reflected in the air quality improvement in the city. Mobile measurements carried out during six runs within a 24-hour period in 2017 and 2020 indicated a decrease of the average PM_2.5 and PM₁₀ concentrations by ∼ 30% and ∼14%, respectively. In turn, stationary measurement results obtained for the same periods demonstrated their increase by respectively ∼35% and ∼106% and a decrease in the average NO₂, NO_x, C₆H₆ and CO concentrations. This could have been impacted by meteorological factors and emissions from other, non-traffic-related sources, mainly from residential coal burning. The changes in the vehicle fleet structure could also have played a role.

波兰卢布林在 2020 年 COVID-19 封锁期间和 2017 年同期的移动和固定空气质量测量结果的比较表明，交通强度大幅下降了 50% 以上，尤其是在 2020 年的某些时期封城期间的一天仅部分反映在城市空气质量的改善上。在 2017 年和 2020 年的 24 小时内进行的六次移动测量表明，PM _2.5和 PM ₁₀的平均浓度分别降低了约 30% 和约 14%。反过来，同一时期获得的固定测量结果表明它们分别增加了 ~35% 和 ~106%，并且平均 NO ₂、NO _x、C减少了₆ H ₆和CO浓度。这可能受到气象因素和其他与交通无关的排放源（主要来自住宅燃煤）的影响。车队结构的变化也可能发挥了作用。