The mining activity in open-pit coal sites exerts a high pressure over the surrounding environment and on the health of people working and living nearby. Using data form a total of six field campaigns, this study aimed to capture the level of exploitation activities in the residential area close to the coal open-mine in terms of mass concentrations and total carbon fractions (TC) of ambient PM10, PM2.5 samples. Sampling campaigns were performed between spring of 2018 and spring of 2020, covered both working (full time, part-time) and non-working days at the coal exploitation, and captured also the seasonal variations of different fractions of PM and of their carbonaceous fraction. Fine fraction was also analyzed based on the aerosol Angstrom exponent, determined from measurements of the aerosol scattering coefficient at 450 nm, 550 nm and 700 nm by a nephelometer. The mass concentrations of PM and TC showed significant variations from full time working days to non-working days. The air quality (AQ) level is determined by the air quality index (AQI) specific for PM10. In situ measurements clearly indicated that AQIlocal gives better image on the level of air pollution than the AQIestim from AQ monitoring stations in the region, closest to the Matasari site. Insights into the morphology and composition of particles were obtained by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX/EDS) and Fourier transform infrared spectroscopy (FTIR) analyses. Major elements that were identified C, O, Si, Ca, K, S, Cu, Ni, Fe, Mg, Ti have both crustal and anthropogenic origin, in various proportions.

Air Pollution Monitoring: A Case Study from Romania | InTechOpen, Published on: 2016-12-14. Authors: Gabriela Iorga

Warm clouds, consisting of liquid cloud droplets, play an important role in modulating the amount of incoming solar radiation to Earth's surface and thus the climate. The size and number concentration of these cloud droplets control the reflectance of the cloud, the formation of precipitation and ultimately the lifetime of the cloud. Therefore, in situ observations of the number and diameter of cloud droplets are frequently performed with cloud and aerosol spectrometers, which determine the optical diameters of cloud particles (in the range of up to a few tens of micrometers) by measuring their forward-scattering cross sections in visible light and comparing these values with Mie theoretical computations. The use of such instruments must rely on a fast working scheme consisting of a limited pre-defined uneven grid of cross section values that corresponds to a theoretically derived uneven set of size intervals (bins). However, as more detailed structural analyses of warm clouds are needed to improve future climate projects, we present a new numerical post-flight methodology using recorded particle-by-particle sample files. The Mie formalism produces a complicated relationship between a particle's diameter and its forward-scattering cross section. This relationship cannot be expressed in an analytically closed form, and it should be numerically computed point by point, over a certain grid of diameter values. The optimal resolution required for constructing the diagram of this relationship is therefore analyzed. Cloud particle statistics are further assessed using a fine grid of particle diameters in order to capture the finest details of the cloud particle size distributions. The possibility and the usefulness of using coarser size grids, with either uneven or equal intervals, is also discussed. For coarse equidistant size grids, the general expressions of cloud microphysical parameters are calculated and the ensuing relative errors are discussed in detail. The proposed methodology is further applied to a subset of measured data, and it is shown that the overall uncertainties in computing various cloud parameters are mainly driven by the measurement errors of the forward-scattering cross section for each particle. Finally, the influence of the relatively large imprecision in the real and imaginary parts of the refractive index of cloud droplets on the size distributions and on the ensuing cloud parameters is analyzed. It is concluded that, in the presence of high atmospheric loads of hydrophilic and light-absorbing aerosols, such imprecisions may drastically affect the reliability of the cloud data obtained with cloud and aerosol spectrometers. Some complementary measurements for improving the quality of the cloud droplet size distributions obtained in post-flight analyses are suggested.

The COVID-19 pandemic has provided an opportunity to examine the impact of reduced human activity on air quality. This study assesses the levels of particulate matter (PM₁₀) in three cities—Bucharest, Brașov, and Iași—during the pandemic restrictions in 2020, comparing them with data from the pre-pandemic period (2017–2019) and post-lockdown period (2021–2022). The results show a significant decrease in PM₁₀ levels during the lockdown, which is closely associated with reduced traffic and mobility. Notably, while PM₁₀ concentrations initially spiked at the beginning of 2020, they markedly declined following the enforcement of lockdown measures, during which mobility to workplaces in these cities decreased by about 60% in Bucharest, 50% in Brașov, and 45% in Iași. Health risks related to PM₁₀ exposure were evaluated using the hazard quotient method, following EU and WHO guidelines. Despite the reduction in pollution levels in 2020, the findings suggest long-term human health risks for residents of these cities. This research highlights the critical need for sustainable strategies to address air quality issues in urban areas and protect public health.

Stratocumulus clouds represent one of the key components of the Earth's radiative balance because it generally reflects incident solar radiation. The aim of the study is to understand the cloud occurrence and characteristics of stratocumulus clouds using satellite data collected from Dec 2019 to Feb 2021. The time series for cloud characteristics contained 10944 hourly profiles of which 1513 were for Stratocumulus clouds. We used a statistical cloud classification model based on data on cloud optical depth and cloud pressure top. Of the total clouds measured, Cumulus clouds were the most frequently detected (25 %), followed by Altocumulus clouds (17.48 %), Cirrus clouds (17.01 %) and Stratocumulus clouds (13.82 %). We focused on the Stratocumulus clouds. They represent a higher percentage of the total number of clouds detected, especially, in the winter months. A series of macrophysical and microphysical stratocumulus cloud parameters (cloud cover fraction, cloud top temperature, cloud top pressure, cloud height, cloud optical depth, liquid water path) were extracted from the Clouds and the Earth's Radiant Energy System (CERES) database for Magurele, a region in south west Bucharest, Romania. The highest median value for liquid water path was observed in winter 2020–2021 (61.4 g m-2), reflecting the large number of Stratocumulus cloud observations during this period. The lowest median value for liquid water path was 35.14 g m-2 in summer 2020. The cloud water radius of the liquid particles has similar median values ​​(8.67 - 8.92 μm) during the study period except for the winter 2020–2021, when the median value of the radius had the maximum value (9.69 μm). We calculated cloud geometric depth of the stratocumulus clouds, whose median value varied between 141.7 m (summer) and 187.3 m (winter). All these characteristics help us better understand the climatology of stratocumulus clouds [1].AcknowledgmentGLSG work was supported by the Romanian Nucleu Programme - Project PN 19 06 03 03. GLSG work was also supported by the University of Bucharest, PhD research grant. SS, GI and TH acknowledge the support from NO Grants 2014-2021, under Project EEA-RO-NO-2019-0423, contract no 31/01.09.2020.  BA work was supported by a grant of the Romanian Ministry of Education and Research, CNCS-UEFISCDI (Project No. PN-III-P1-1.1-TE-2019-0649) within PNCDI III. BA work was also supported by the Romanian National Core Program (Contract No. 18N/2019). Present research [1] was accepted for publication and is currently in press at Romanian Reports in Physics (http://www.rrp.infim.ro/IP/AP601.pdf).