Air Quality of Work, Residential, and Traffic Areas during the COVID-19 Lockdown with Insights to Improve Air Quality

This study investigated the concentrations of air pollutants (NO, NO2, NOx, SO2, CO, O3, PM10, and PM2.5) at three sites with different traffic loads (work, residential, and traffic sites) before, during, and after the COVID-19 lockdown. The main objective of this study was to evaluate the effects and associated potential pollution control implications of the lockdown on the quality of ambient air at three selected sites in the urban area of Riyadh City. The average concentrations of NO, NO2, NOx, and CO decreased during the lockdown period by 73%, 44%, 53%, and 32% at the work site; 222%, 85%, 100%, and 60% at the residential site; and 133%, 60%, 101%, and 103% at the traffic site relative to the pre-lockdown period, respectively. The average concentration of O3 increased by 6% at the work site, whereas the concentration of SO2 increased by 27% at the residential site and decreased by 6.5% at the work site. The changes in PM10 and PM2.5 varied and did not exhibit a clear pattern. The air quality index (AQI) results indicated that the contribution to “undesired” air quality by O3 was 35.29% of the lockdown period at the work site while contributions to undesired air quality by PM10 and PM2.5 were 75.6% and 100% at the work site, 94.5% and 100% at the residential site, and 96.7% and 100% at the traffic site, respectively. The findings of this study are useful for devising effective urban pollution abatement policies. Applying control measures comparable to the lockdown measures over one week will result in a decrease of approximately 19% and 15% in CO mean concentration and 25% and 18% in NO2 mean concentration at residential and traffic sites, respectively.

The Evaluation of the Impact of a Saharan Event on Particulate Matter Using Compositional Data Analysis

The proposed approach based on compositional data analysis was applied on simultaneous measurements of the mineral element concentrations of PM10 and PM2.5 from a typical suburban site with and without a Saharan event. The suburban site is located in the city of Rome. The selected mineral elements were Al, Si, Ca, Fe, Ti, Mg, and Sr. The data relating to these elements are reported in a previous study. The considered elements are mainly related to mineral matter. The proposed approach allows statistically validating that the mineral element concentrations of PM during days with a Saharan event differ from those without a Saharan event in terms of mineral element composition and size distribution. In particular, the results showed that the compositional data analysis applied to simultaneous measurements of mineral element concentrations of PM10 and PM2.5 is a helpful technique that can be used to study environmental sites affected by natural sources such as Saharan events. Moreover, the presented technique can be handy in all those conditions where it is important to discriminate whether the occurrence of an exceedance or a violation of the daily limit value established for PM could also be due to natural sources.

Justification of measures to protect against exposure nicotine-containing products in enclosed spaces

Introduction. The introduction of amendments and additions to the anti-smoking Federal Law No. 15-FZ of 23.02.2013 in 2020 contributed to the cardinal revision of the name of this law and the introduction of a ban on consumption of any nicotine-containing products in public places. There are no separate, specially allocated isolated premises provided for the consumption of tobacco products and other types of nicotine-containing products by law, even though specially conducted studies have shown significantly different levels of additional inhalation risk arising from air pollution when consuming tobacco products and electronic nicotine delivery systems or heating tobacco. The aim of the study: based on experimental data, to justify the multiplicity of air exchange in unique isolated rooms designed to protect against the effects of ambient tobacco smoke, the consequences of tobacco consumption or nicotine-containing products. Materials and methods. The study was subject to 3 types of nicotine-containing products: tobacco cigarettes (cigarettes), an electronic nicotine delivery system (ENDS) and an electronic tobacco heating system (ETHS). In the course of the study were carried out: a series of experiments on the consumption of nicotine-containing products in various ways in a specially equipped indoor room, air sampling and laboratory studies were performed, the gross and specific emissions of chemicals entering the air environment from one unit of production per hour were calculated, the selection of priority chemicals for calculating the air removed from the room when using nicotine-containing products of each type was carried out, the necessary level of air exchange of premises was calculated, intended for the consumption of tobacco or nicotine. Results. The indoor air quality assessment showed that the main components of the gross intake into the air environment are suspended particles and carbon monoxide when smoking cigarettes. However, taking into account the values of the maximum permissible concentrations, the most significant contribution to the integral indicator is made by acetaldehyde and suspended particles PM10 and PM2.5. Using ENDS, the most significant pollutants were acetaldehyde and carbon monoxide, using ETHS - acetaldehyde and suspended particles PM10 and PM2.5. For all the investigation types of products, the priority substance for calculating the removed air is acetaldehyde, its share in the structure of all detected pollutants was: for cigarettes - 56.27%, for ENDS - 62.7%, for ETHS - 82.51%, in connection with which its specific values can be used to calculate the consumption of the removed air when modelling a specially allocated room intended for the consumption of tobacco products and other types of nicotine-containing products. Conclusion. The obtained findings demonstrated an obvious, more than 10-fold difference in the requirements for air exchange of premises intended for cigarette smoking and premises intended for the consumption of ENDS or ETHS, at the same intensity of consumption. Therefore, when organizing specially designated places for smoking or the consumption of nicotine-containing products, it is advisable to separate them depending on the type of products consumed: tobacco smoking separately, ENDS and ETHS consumption separately.

Characteristics of atmospheric air pollution by fine particles based on regional monitoring data

Introduction. Air pollution with particulate matter (PM) is a serious global problem. In the Russian Federation, regular field measurements of PMs in the ambient air are carried out only in a few cities, and the data, as a rule, are not systematized. Aim of the study: long-term analysis of the data set on concentrations of fine particles in the ambient air of the city of Kazan. Material and methods. Long-term analysis of ambient air pollution by fine particles in the city of Kazan for the period from 2016 to 2020 has been carried out. To study the effect of separate factors (year, measurement time during the day, climatic conditions, the presence of other pollutants) on the levels of PM10 and PM2.5, regression analysis was applied based on the method of mixed models. To characterize the elemental composition of the PM2.5 fraction, sampling of atmospheric air on PVC filters was carried out by use of 100 NR impactor (TSI, USA). The step function and MPPD model were applied to calculate the number of particles and the mass of the deposited fraction of fine particulate matter in different regions of the human respiratory tract. Results. The PM10 concentrations remained stable over a 5-year period, while the PM2.5 concentrations decreased. At the same time, an increase in the maximum annual concentrations of both fractions was observed. The concentrations of PM10 and PM2.5 significantly depended on climatic conditions. The presence of nitrogen oxides and organic carbon in the ambient air was significantly associated with higher concentrations of PM10 and PM2.5. The elemental composition of PM2.5 fraction was represented mainly by carbon (C) (from 86.16% to 93.45%). Mathematical modeling has shown that PM10 is mainly deposited in the upper respiratory tract, and their presence in the tracheobronchial and alveolar zones is insignificant. PM2.5 particles reach the lower respiratory tract and alveolar area. Conclusion. A statistically significant upward long-term trend in the maximum annual ambient concentrations for both fractions of fine particles can increase health risks. Secondary pollutants (nitrogen oxides, organic carbon) are important factors for the formation of secondary particles in the ambient air. The results obtained indicate that when assessing the risks to public health, it is necessary not only to use the concentrations of fine particles in ambient air, but also to consider the degree of deposition of separate fractions in different parts of the human respiratory tract, considering the alleged pathogenesis and priority target cells characteristic of individual diseases.

Statistical Modeling for PM10, PM2.5 and PM1 at Gangneung Affected by Local Meteorological Variables and PM10 and PM2.5 at Beijing for Non- and Dust Periods

Multiple statistical prediction modeling of PM10, PM2.5 and PM1 at Gangneung city, Korea, was performed in association with local meteorological parameters (air temperature, wind speed and relative humidity) and PM10 and PM2.5 concentrations of an upwind site in Beijing, China, in the transport route of Chinese yellow dusts which originated from the Gobi Desert and passed through Beijing to the city from 18 March to 27 March 2015. Before and after the dust periods, the PM10, PM2.5 and PM1 concentrations showed as being very high at 09:00 LST (the morning rush hour) by the increasing emitted pollutants from vehicles and flying dust from the road and their maxima occurred at 20:00 to 22:00 LST (the evening departure time) from the additional pollutants from resident heating boilers. During the dust period, these peak trends were not found due to the persistent accumulation of dust in the city from the Gobi Desert through Beijing, China, as shown in real-time COMS-AI satellite images. Multiple correlation coefficients among PM10, PM2.5 and PM1 at Gangneung were in the range of 0.916 to 0.998. Multiple statistical models were devised to predict each PM concentration, and the significant levels through multi-regression analyses were p < 0.001, showing all the coefficients to be significant. The observed and calculated PM concentrations were compared, and new linear regression models were sequentially suggested to reproduce the original observed PM values with improved correlation coefficients, to some extent.

Acute Effects of Particulate Matter on All-Cause Mortality in Urban, Rural, and Suburban Areas, Italy

Background: Short-term exposure to particulate matter (PM) has been related to mortality worldwide. Most evidence comes from studies conducted in major cities, while little is known on the effects of low concentrations of PM and in less urbanized areas. We aim to investigate the relationship between PM and all-cause mortality at national level in Italy. Methods: Daily numbers of all-cause mortality were collected for all 8092 municipalities of Italy, from 2006 to 2015. A satellite-based spatiotemporal model was developed to estimate daily PM10 (inhalable particles) and PM2.5 (fine particles) concentrations at 1-km resolution. Multivariate Poisson regression models were fit to estimate the association between daily PM and mortality at province level, and then, results were pooled with a random-effects meta-analysis. Associations were estimated by combination of age and sex and degree of urbanization of the municipalities. Flexible functions were estimated to explore the shape of the associations at low PM concentrations. Results: We analyzed 5,884,900 deaths (40% among subjects older than 85 years, 60% occurring outside the main urban areas). National daily mean (interquartile range) PM10 and PM2.5 concentrations were 23 (14) μg/m3 and 15 (11) μg/m3, respectively. Relative increases of mortality per 10 μg/m3 variation in lag 0–5 (average of last six days since death) PM10 and PM2.5 were 1.47% (95% Confidence Intervals (CI): 1.15%, 1.79%) and 1.96% (1.33%, 2.59%), respectively. Associations were highest among elderly and women for PM10 only, similar between rural and urbanized areas, and were present even at low concentrations, e.g., below WHO guidelines. Conclusions: Air pollution was robustly associated with peaks in daily all-cause mortality in Italy, both in large cities and in less urbanized areas of Italy. Current WHO Air Quality Guidelines (2021) for PM10 and PM2.5 are not sufficient to protect public health.

Eurodelta multi-model simulated and observed PM trends in Europe in the period of 1990–2010

The Eurodelta-Trends multi-model experiment, aimed to assess the efficiency of emission mitigation measures in improving air quality in Europe during 1990–2010, was designed to answer a series of questions regarding European pollution trends. i.e. were there significant trends detected by observations? do the models manage to reproduce observed trends? how close is the agreement between the models and how large are the deviations from observations? In this paper, we address these issues with respect to PM pollution. An in-depth trend analysis has been performed for PM10 and PM2.5 for the period of 2000–2010, based on results from six chemical transport models and observational data from the EMEP (Cooperative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe) monitoring network. Given harmonization of set up and main input data, the differences in model results should mainly result from differences in the process formulations within the models themselves, and the spread in the models simulated trends could be regarded as an indicator for modelling uncertainty. The model ensemble simulations indicate overall decreasing trends in PM10 and PM2.5, with reduction by between 2 and 6 μg m−3 m−3 (or between 10 and 30 %) from 2000 to 2010. Compared to PM2.5, relative PM10 trends are weaker due to large inter-annual variability of natural coarse PM within the former. The changes in the concentrations of PM individual components are in general consistent with emission reductions. There is a reasonable agreement in PM trends estimated by the individual models, with the inter-model variability below 30–40 % over most of Europe, increasing to 50–60 % in northern and eastern parts of EDT domain. Averaged over measurement sites (26 for PM10 and 13 for PM2.5), the mean ensemble simulated trends are −0.24 and −0.22 μg m−3 year−1 for PM10 and PM2.5, which are somewhat weaker than the observed trends of −0.35 and −0.40 μg m−3 year−1, respectively, partly due to models underestimation of PM concentrations. The correspondence is better in relative PM10 and PM2.5 trends, which are −1.7 and −2.0 % year−1 from the model ensemble and −2.1 and −2.9 % year−1 from the observations, respectively. The observations identify significant trends for PM10 at 56 % of the sites and for PM2.5 at 36 % of the sites, which is somewhat less that the fractions of significant modelled trends. Further, we find somewhat smaller spatial variability of modelled PM trends with respect to the observed ones across Europe and also within individual countries. The strongest decreasing PM trends and the largest number of sites with significant trends is found for the summer season, according to both the model ensemble and observations. The winter PM trends are very weak and mostly insignificant. One important reason for that is the very modest reductions and even increases in the emissions of primary PM from residential heating in winter. It should be kept in mind that all findings regarding modeled versus observed PM trends are limited the regions where the sites are located. The analysis reveals a considerable variability of the role of the individual aerosols in PM10 trends across European countries. The multi-model simulations, supported by available observations, point to decreases in SO4−2 concentrations playing an overall dominant role. Also, we see relatively large contributions of the trends of NH4+ and NO3− to PM10 decreasing trends in Germany, Denmark, Poland and the Po Valley, while the reductions of primary PM emissions appears to be a dominant factor in bringing down PM10 in France, Norway, Portugal, Greece and parts of the UK and Russia. Further discussions are given with respect to emission uncertainties and the effect of inter-annual meteorological variability on the trend analysis.