Application of the Correction Function to Improve the Quality of PM Measurements with Low-Cost Devices

Reliable information on the particulate matter (PM) concentration in the air is provided by professional, reference measuring devices. In recent times, however, measuring devices using low-cost PM sensors have been gaining more and more popularity. Low-cost PM sensors are not as accurate as professional devices and can under certain circumstances significantly distort results. Therefore comparative measurements with professional devices and the determination of the corrective function are necessary. The article presents the results of tests on the accuracy of measurements made with the use of such sensors after applying a correction function. The form of the correction function was determined based on several months of comparative tests low-cost sensors with reference device. Then, for a different set of low-cost sensors, a correction function was applied and again, during several months of research, the measurement results were compared with a reference device. This made it possible to determine the real measurement uncertainty of this type of equipment, as well as the need to support measurements using earlier comparative tests. Results showed, that for analysed low-cost PM sensors and correction function measurement error was about 15%

Preliminary comparative assessment and elements of equivalence of air pollution measurement results of portable monitoring stations with using stochastic models

This article is an attempt to assess the suitability of new non-reference mobile measuring devices for the analysis of PM10 concentrations. The aim is to compare the concentration daily values measured by these devices with the concentrations obtained by the reference device. It also examines the possibility of building models that correct these values to equivalent reference values. The analysis allows to conclude that the properties of the obtained measurements indicate a good chance of constructing an effective model of correcting the concentration values. Comparison of frequency, time variation and correlation of concentrations indicates the ability to demonstrate the equivalence of mobile devices with the reference method

Preliminary comparative assessment and elements of equivalence of air pollution measurement results of portable monitoring stations with using stochastic models

This article is an attempt to assess the suitability of new non-reference mobile measuring devices for the analysis of PM10 concentrations. The aim is to compare the concentration daily values measured by these devices with the concentrations obtained by the reference device. It also examines the possibility of building models that correct these values to equivalent reference values. The analysis allows to conclude that the properties of the obtained measurements indicate a good chance of constructing an effective model of correcting the concentration values. Comparison of frequency, time variation and correlation of concentrations indicates the ability to demonstrate the equivalence of mobile devices with the reference method

The Influence of Marine Traffic on Particulate Matter (PM) Levels in the Region of Danish Straits, North and Baltic Seas

The aim of the study was to determine air pollution over the sea surface (North Sea and Baltic Sea) compared to the situation in ports, as well as to examine the impact of ships on the level of particulate matter (PM) concentration. The measurements, made during the two-week cruise of the tall ship Fryderyk Chopin, demonstrated that the principal source of PM emission over the sea surface are passing ships equipped with internal combustion engines, including quite numerous units powered by marine oil. The highest pollution levels were observed in locations distant from the coast, with increasing concentrations when other ships were approaching. During the cruise, at least two places were identified with increased PM concentration (18⁻28 μg/m3 for PM10 and 15⁻25 μg/m3 for PM2.5) caused by passing ships. The share of PM2.5 fraction in the general PM concentration in these places increased from 70⁻72% to 82⁻85%, which means that combustion emission dominated. In turn, measurements made in ports (Copenhagen and Kołobrzeg) showed lower levels of air pollution and indicated a typical variability of the PM concentrations characteristic for land areas. The results confirm the need for determining suitable solutions for sustainable sea transport

Molecular Mechanisms of N-Acetylcysteine in RSV Infections and Air Pollution-Induced Alterations: A Scoping Review

N-acetylcysteine (NAC) is a mucolytic agent with antioxidant and anti-inflammatory properties. The respiratory syncytial virus (RSV) is one of the most important etiological factors of lower respiratory tract infections, and exposure to air pollution appears to be additionally associated with higher RSV incidence and disease severity. We aimed to systematically review the existing literature to determine which molecular mechanisms mediate the effects of NAC in an RSV infection and air pollution, and to identify the knowledge gaps in this field. A search for original studies was carried out in three databases and a calibrated extraction grid was used to extract data on the NAC treatment (dose, timing), the air pollutant type, and the most significant mechanisms. We identified only 28 studies conducted in human cellular models (n = 18), animal models (n = 7), and mixed models (n = 3). NAC treatment improves the barrier function of the epithelium damaged by RSV and air pollution, and reduces the epithelial permeability, protecting against viral entry. NAC may also block RSV-activated phosphorylation of the epidermal growth factor receptor (EGFR), which promotes endocytosis and facilitates cell entry. EGFR also enhances the release of a mucin gene, MUC5AC, which increases mucus viscosity and causes goblet cell metaplasia; the effects are abrogated by NAC. NAC blocks virus release from the infected cells, attenuates the cigarette smoke-induced shift from necrosis to apoptosis, and reverses the block in IFN-γ-induced antiviral gene expression caused by the inhibited Stat1 phosphorylation. Increased synthesis of pro-inflammatory cytokines and chemokines is induced by both RSV and air pollutants and is mediated by the nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways that are activated in response to oxidative stress. MCP-1 (monocyte chemoattractant protein-1) and RANTES (regulated upon activation, expressed and secreted by normal T cells) partially mediate airway hyperresponsiveness (AHR), and therapeutic (but not preventive) NAC administration reduces the inflammatory response and has been shown to reduce ozone-induced AHR. Oxidative stress-induced DNA damage and cellular senescence, observed during RSV infection and exposure to air pollution, can be partially reversed by NAC administration, while data on the emphysema formation are disputed. The review identified potential common molecular mechanisms of interest that are affected by NAC and may alleviate both the RSV infection and the effects of air pollution. Data are limited and gaps in knowledge include the optimal timing or dosage of NAC administration, therefore future studies should clarify these uncertainties and verify its practical use

Children exposure to PM2.5 in kindergarten classrooms equipped with air purifiers - a pilot study

Children exposure to PM2.5 is associated with several negative health effects. Particulate air pollution in the ambient and indoor air could lead to exacerbation of respiratory diseases and even influence cognitive function in children. One of the methods to improve indoor air quality is to use electronic air purifiers. Such an equipment is still not commonly used in Polish kindergartens and homes. The aim of the study was to assess changes in children exposure to particulate air pollution in kindergarten classrooms due to the occurrence of air purifier. Automatic PM2.5 concentration monitors were used to assess the air quality changes in the indoor and ambient air. As it was a pilot study, four kindergartens in Warsaw has been chosen as research fields. Concentration measurements were conducted in cold season. In each kindergarten measurements of the PM2.5 concentration were made in two classrooms - one with air purifier switched on and the other one without air purification. Changes in air quality were observed due to opening windows and the presence of the children. Air quality in classrooms with air purification was on average almost 40%-50% better than in those without any procedures to decrease air pollutants concentration

Children exposure to PM

Children exposure to PM2.5 is associated with several negative health effects. Particulate air pollution in the ambient and indoor air could lead to exacerbation of respiratory diseases and even influence cognitive function in children. One of the methods to improve indoor air quality is to use electronic air purifiers. Such an equipment is still not commonly used in Polish kindergartens and homes. The aim of the study was to assess changes in children exposure to particulate air pollution in kindergarten classrooms due to the occurrence of air purifier. Automatic PM2.5 concentration monitors were used to assess the air quality changes in the indoor and ambient air. As it was a pilot study, four kindergartens in Warsaw has been chosen as research fields. Concentration measurements were conducted in cold season. In each kindergarten measurements of the PM2.5 concentration were made in two classrooms - one with air purifier switched on and the other one without air purification. Changes in air quality were observed due to opening windows and the presence of the children. Air quality in classrooms with air purification was on average almost 40%-50% better than in those without any procedures to decrease air pollutants concentration