ABSTRACT
In this paper, the authors investigated changes in mass concentrations of particulate matter (PM) during the Coronavirus Disease of 2019 (COVID-19) lockdown. Daily samples of PM1, PM2.5 and PM10 fractions were measured at an urban background sampling site in Zagreb, Croatia from 2009 to late 2020. For the purpose of meteorological normalization, the mass concentrations were fed alongside meteorological and temporal data to Random Forest (RF) and LightGBM (LGB) models tuned by Bayesian optimization. The models' predictions were subsequently de-weathered by meteorological normalization using repeated random resampling of all predictive variables except the trend variable. Three pollution periods in 2020 were examined in detail: January and February, as pre-lockdown, the month of April as the lockdown period, as well as June and July as the "new normal". An evaluation using normalized mass concentrations of particulate matter and Analysis of variance (ANOVA) was conducted. The results showed that no significant differences were observed for PM1, PM2.5 and PM10 in April 2020-compared to the same period in 2018 and 2019. No significant changes were observed for the "new normal" as well. The results thus indicate that a reduction in mobility during COVID-19 lockdown in Zagreb, Croatia, did not significantly affect particulate matter concentration in the long-term..
Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Air Pollutants/analysis , Air Pollution/analysis , Bayes Theorem , COVID-19/epidemiology , Cities , Communicable Disease Control , Croatia/epidemiology , Environmental Monitoring/methods , Humans , Machine Learning , Particulate Matter/analysisABSTRACT
The participants of "Air Protection 2021" presented their experiences and the issues they encounter in their work through the 54 presentations in following topics: * Topic 1 - Managing air quality - inspection and control * Topic 2 - Atmospheric emissions of pollutants * Topic 3 - Monitoring ambient air pollution * Topic 4 - Developing and testing measuring methods * Topic 5 - Estimating exposure to air pollutants and impact on health * Topic 6 - Air Protection in physical planning, construction, and environmental protection * Topic 7 - EFCA session "Air pollution from shipping emissions" * Topic 8 - IUAPPA and Global Forum special session: "Respiratory pandemics and air pollution: exploring the links" The conference started on 15th September with three introductory lectures: * Richard Mills (IUAPPA): GLOBAL AIR POLLUTION: LESSONS FROM THE LAST 20 YEARS * Sandra Krmpotić, Nina Zovko, Gordan Došen (Ministry of Economy and Sustainable Development of the Republic of Croatia): AN OVERVIEW OF LEGISLATION IN THE FIELD OF AIR QUALITY AT NATIONAL AND EU LEVEL * Vedranka Bobić (Expert witness for environmental protection, occupational safety and environmental accidents): EXPERT WITNESS EXAMINATION AND COURT PRACTICE OF ENVIRONMENTAL FACTORS NOT REGULATED BY LAW- ODOURS Introductory lectures were followed by 17 presentations in Croatian on Topic 1, 2, and 3. Due to her effort CAPPA was first admitted to IUAPPA and then in 1998 to EFCA, where Vladimira Vaðić held its vice-presidency since 2020 until her retirement. Since 2019 she is a honorary member of CAPPA. [...]Andrzej Jagusiewicz held a presentation on the cost and environmental benefits of IMO regulations of shiporiginated SOx and NOx emissions, assessed for the case of the Baltic sea.
ABSTRACT
Due to the pandemic of SARS-CoV-2 in Croatia, all unnecessary activities were prohibited during the designated lockdown period (March-May 2020). With reduced human activity, levels of some air pollutants decreased. In this study, mass concentrations of the PM1 particle fraction (particulate matter with an equivalent aerodynamic diameter < 1 µm) and polycyclic aromatic hydrocarbons (PAHs) in PM1 and NO2 were measured and compared with concentrations measured in the same period the year before. Air pollutant concentrations were measured at two measuring sites: urban residential and urban traffic. Our results show a concentration decrease by 35% for NO2 and PM1 particles and by 26% for total PAHs at the traffic measuring site. At the residential measuring site, only concentrations of NO2 decreased slightly, but PM1 particles and PAHs were similar to the year before.