Levels of Main Pollutants during #Istayathome for the Coronavirus Pandemic in Rome Urban Air

Abstract

The aim of this study is to evaluate and discuss the impact that the restrictive measures adopted for coronavirus have had on the main air pollutants. CO and NOx trends showed a reduction in levels from January to April 2020. A reduction in NOx (54%) concentration and in CO (7.6%) was detected by comparing the average of their values measured from March 9th - April 15th in 2019 and in 2020. A reduction in NOx concentrations compared to the average of previous four years was detected in March (47%) and April 2020 (73%). PM2.5 and PM10 concentrations measured by the Lazio Regional Agency for Environmental Protection in various urban sites in Rome, were studied. PM2.5 and PM10 trends from January 1st to April 15th showed a concentration decrease, although during this period they exceeded the recommended daily level several times. PM10 has exceeded the limit value from March 28th-30th, and the analysis of the backward trajectories of the NOAA detected a desert dust transport from the Caspian Sea. PM2.5 showed high values from March 18th-22nd and from April 8th-13th. A long-range transport of air masses from regions with high SO2 emission sources was detected, while analyzing the daily trends of CO, SO2 and radon for these periods. The influence of domestic heating on PM levels was evaluated for the years 2018 and 2019. The results did not show a significant impact of domestic heating on PM levels.