Assessment of NO2 Pollution Level during the COVID-19 Lockdown in a Romanian City

Abstract

This study investigates changes in pollution associated with the lockdown period caused by the COVID-19 pandemic in Galati (45.43° N, 28.03° E), a Romanian city located in the southeast of Romania. The study is focused on nitrogen dioxide (NO2), a trace gas which can be related to emissions from industrial activities, heating, and transportation. The investigation is based on in situ observations from local Air Quality Monitoring Stations (AQMS) and mobile remote sensing observations by Differential Optical Absorption Spectroscopy (DOAS) technique. We also show results of the NO2 vertical column measured by TROPOMI (TROPOspheric Monitoring Instrument), a space instrument onboard of satellite mission Sentinel-5P, to complement local ground-based measurements. For in situ observations, the lockdown interval (23 March 2020–15 May 2020) was separated from normal periods. The decrease in local NO2 concentration during lockdown, measured in situ, is rather small, of about 10–40% at the most, is observed only at some stations, and is better seen during workdays than during weekends. We conclude that the decrease in NO2 content over Galati city during lockdown is relatively small and may be attributed to the reduction in local traffic, a consequence of special measures and restrictions imposed during the COVID-19 lockdown by the Romanian authorities.

Advancements in Mobile-Based Air Pollution Detection: From Literature Review to Practical Implementation

“…Research [33] used mobile technology based on measuring the effect of light absorption depending on the concentration of particles in the air. The area where the measurement was made is one of the biggest cities in Romania, with a large amount of traffic.…”

Study of the Effects of the COVID-19 Pandemic on Air Quality: A Case Study in Cluj-Napoca, Romania

“…Secondly, the impact on environment generated by COVID-19 is important for Romanian residents [40], together with the social and economic impacts. So, studies on air pollution were carried out in other regions in Romania, such as in the capital city of Bucharest [41], in major cities in Northeastern Romania: Bacau [42], in Southeastern Romania: Galati [43] and in Central Romania: Brasov [44], but not in the Cluj area. The studies observed that the pandemic crises had limited positive effects on reducing the pollution generated by traffic, and not so much from industries, and, also, it was pointed out that the bigger the city, the better the positive effect of pollution reduction.…”

Air quality changes in NE Romania during the first Covid 19 pandemic wave

“…Another case study conducted in Bucharest on NO 2 concentrations shows the same decreasing trend as in other cities in Europe, only some sudden increases could be observed due to fires in landfills [ 50 ]. NO 2 concentrations recorded at the in situ stations in the city of Galati (SE Romania), during the state of emergency, decreased between 10 and 40%, at some stations, being best highlighted during the working days [ 51 ]. In April 2020, during the state of emergency, the levels of PM 2.5 and PM 10 decreased also in Brașov, the most important tourist center in Romania [ 52 ].…”