Estimation of plant pollution removal capacity based on intensive air quality measurements

This study investigated the role of present vegetation in improving air quality in Bucharest (Romania) by analyzing six years of air quality data (PM₁₀ and NO₂) from multiple monitoring stations. The target value for human health protection is regularly exceeded for PM₁₀ and not for NO₂ over time. Road traffic has substantially contributed (over 70%) to ambient PM₁₀ and NO₂ levels. The results showed high seasonal variations in pollutant concentrations, with a pronounced effect of vegetation in reducing PM₁₀ and NO₂ levels. Indeed, air quality improvements of 7% for PM₁₀ and 25% for NO₂ during the growing season were reported. By using Principal Component Analysis and pollution data subtraction methodology, we have disentangled the impact of vegetation on air pollution and observed distinct annual patterns, particularly higher differences in PM₁₀ and NO₂ concentrations during the warm season. Despite limitations such as a lack of full tree inventory for Bucharest and a limited number of monitoring stations, the study highlighted the efficiency of urban vegetation to mitigate air pollution.