A Study of PM 10, PM 2.5 Concentrations in the Atmospheric Air in Kraków, Poland

The air in Kraków is one of the most polluted in Europe. Polish standards for notification and alert levels for PM10 particulate matterare one of the the highest in Europe and exceed the recommendations of the World Health Organization (WHO) for safe daily concentrations by several times. The article presents the results of airborne dust measurements in three districts of Kraków. The study hasshown that the concentration of PM2.5 and PM10 particulate matter exceeded the annual average permissible levels. Empirical measurements of PM2.5 show significantly higher air pollution values than the data notified by stationary monitoring stations installed intwo locations. The high value of Pearson linear correlation coefficient confirms that weather conditions have a significant impact on airquality in Kraków. Wind speed in the autumn and winter seasons has by far the greatest influence on air quality in al. Krasińskiego,in the Ruczaj and Kurdwanów districts. A strong negative correlation was displayed. Manual measurements should be used to verifydata obtained from air monitoring stations. It is to be expected that, in Kraków, air purity will improve due to the implementation ofan anti-smog resolution and subsidies for the replacement of obsolete heating systems with more environmentally friendly solutions.

Impact of the Selected Disturbing Factors on Accuracy of the Distance Measurement with the use of Ultrasonic Transducers in a Hard Coal Mine

The article presents tests on the possibility of using ultrasonic transducers for accurate distance measurement in hard coal mines. In order to check the impact of selected disturbing factors on the measurement results, test stands were built, and then a full cycle of measurements with the use of different transducers (AR30 and AR41), which were selected and pre-tested in previous research projects, was realized. The impact of such disturbing factors as airborne dust (coal, stone, lime and mixed dust), changes in temperature and humidity on the propagation of ultrasonic waves, amplitude and measurement accuracy was investigated. The tests were preceded by theoretical analysis. It was found that the transducers selected for the tests had a sufficient accuracy and range, so they can be used in the devices planned to be designed, allowing for the determining of the location of a roadheader in hard coal mine roadways, taking into account technical and legal restrictions. It was also specified which disturbing factors should be compensated and what methods and parameters of this compensation should be used.

Mechanisms and ways of transmission of SARS-CoV-2 coronavirus infection

The relevance of the problem. A new coronavirus infection caused by the SARS-CoV-2 virus has created an emergency situation of international importance. The incidence of it is characterized by a rapid spread across all countries, high morbidity rates, severe complications and mortality. Despite the fact that there are currently vaccines, it is not yet possible to stop the infection. Of particular importance as a preventive measure is the impact on the second link of the epidemic process. In this connection, obtaining objective data on the mechanisms and ways of spreading the SARS-CoV-2 virus will allow for more rational preventive measures and significantly reduce the risk of transmission of infection. The aim is to analyze current data on the mechanisms and ways of spreading the COVID-19 pathogen from available literature sources and to consider possible measures to influence the second link of the epidemiological chain in order to reduce the risks of infection. Materials and methods. The selection of peer-reviewed literature published from 2019 to 2021 was carried out. in the PubMed database and e-Library.ru, as well as links in articles. To obtain statistical data, the Internet resources of the World Health Organization (WHO), open data of Rospotrebnadzor, the Ministry of Health of the Russian Federation, Rosstat were used. Results. Analysis of scientific sources containing information on the mechanisms and ways of transmission of the new coronavirus infection COVID-19 indicates that the authors in their publications mention almost all the mechanisms and ways of transmission of this disease, but to varying degrees of their significance. The main mechanism of the spread of the SARS-CoV-2 virus is aspiration with airborne and airborne dust transmission routes. At the same time, the effect of contact, fecal-oral mechanisms is not excluded, the probability of the implementation of the vertical mechanism of transmission of the pathogen from the mother to the child, as well as the genital tract, is being studied. An important measure for the prevention of a new infection is the impact on the second link of the epidemic process, especially ensuring the highly efficient operation of ventilation and air conditioning systems in medical institutions and public places with a massive crowd of people, as well as compliance with personal preventive measures and disinfection measures.

Surfactant Proteins A/D–CD14 on Alveolar Macrophages Is a Common Pathway Associated With Phagocytosis of Nanomaterials and Cytokine Production

Alveolar macrophages are responsible for clearance of airborne dust and pathogens. How they recognize and phagocytose a variety of engineered nanomaterials (ENMs) with different properties is an important issue for safety assessment of ENMs. Surfactant-associated proteins, specifically existing in the pulmonary surfactant, are important opsonins for phagocytosis of airborne microorganisms. The purposes of the current study are to understand whether opsonization of ENMs by surfactant-associated proteins promotes phagocytosis of ENMs and cytokine production, and to determine whether a common pathway for phagocytosis of ENMs with different properties exists. For these purposes, four ENMs, MWCNT-7, TiO2, SiO2, and fullerene C60, with different shapes, sizes, chemical compositions, and surface reactivities, were chosen for this study. Short-term pulmonary exposure to MWCNT-7, TiO2, SiO2, and C60 induced inflammation in the rat lung, and most of the administered ENMs were phagocytosed by alveolar macrophages. The ENMs were phagocytosed by isolated primary alveolar macrophages (PAMs) in vitro, and phagocytosis was enhanced by rat bronchioalveolar lavage fluid (BALF), suggesting that proteins in the BALF were associated with phagocytosis. Analysis of proteins bound to the 4 ENMs by LC/MS indicated that surfactant-associated proteins A and D (SP-A, SP-D) were common binding proteins for all the 4 ENMs. Both BALF and SP-A, but not SP-D, enhanced TNF-α production by MWCNT-7 treated PAMs; BALF, SP-A, and SP-D increased IL-1β production in TiO2 and SiO2 treated PAMs; and BALF, SP-A, and SP-D enhanced IL-6 production in C60 treated PAMs. Knockdown of CD14, a receptor for SP-A/D, significantly reduced phagocytosis of ENMs and SP-A-enhanced cytokine production by PAMs. These results indicate that SP-A/D can opsonize all the test ENMs and enhance phagocytosis of the ENMs by alveolar macrophages through CD14, suggesting that SP-A/D-CD14 is a common pathway mediating phagocytosis of ENMs. Cytokine production induced by ENMs, however, is dependent on the type of ENM that is phagocytosed. Our results demonstrate a dual role for surfactant proteins as opsonins for both microbes and for inhaled dusts and fibers, including ENMs, allowing macrophages to recognize and remove the vast majority of these particles, thereby, greatly lessening their toxicity in the lung.

Multicomponent Measurement of Respirable Quartz, Kaolinite and Coal Dust using Fourier Transform Infrared Spectroscopy (FTIR): A Comparison Between Partial Least Squares and Principal Component Regressions

Exposure to respirable crystalline silica (RCS) is potentially hazardous to the health of thousands of workers in Great Britain. Both X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy can be used to measure RCS to assess exposures. The current method outlined in the Health and Safety Executive’s (HSE) Methods for the Determination of Hazardous Substances (MDHS) guidance series is ‘MDHS 101 Crystalline silica in respirable airborne dust - Direct-on-filter analyses by infrared spectroscopy or x-ray’. This describes a procedure for the determination of time-weighted average concentrations of RCS either as quartz or cristobalite in airborne dust. FTIR is more commonly employed because it is less expensive, potentially portable and relatively easy to use. However, the FTIR analysis of RCS is affected by spectral interference from silicates. Chemometric techniques, known as Partial Least Squares Regression (PLSR) and Principal Component Regression (PCR), are two computational processes that have the capability to remove spectral interference from FTIR spectra and correlate spectral features with constituent concentrations. These two common chemometric processes were tested on artificial mixtures of quartz and kaolinite in coal dust using the same commercially available software package. Calibration, validation and prediction samples were prepared by collecting aerosols of these dusts onto polyvinylchloride (PVC) filters using a Safety in Mines Personal Dust Sampler (SIMPEDS) respirable cyclone. PCR and PLSR analyses were compared when processing the same spectra. Good correlations between the target values, measured using XRD, were obtained for both the PCR and PLSR models e.g. 0.98–0.99 (quartz), 0.98–0.98 (kaolinite) and 0.96–0.97 (coal). The level of agreement between PCR and PLSR was within the 95% confidence value for each analyte. Slight differences observed between predicted PCR and PLSR values were due to the number of optimal principal components applied to each chemometric process. The presence of kaolinite in these samples caused an 18% overestimation of quartz, for the FTIR, when following MDHS 101 without a chemometric method. Chemometric methods are a useful approach to obtain interference-free results for the measurement of RCS from some workplace environments and to provide a multicomponent analysis to better characterise exposures of workers.

Screening Coarse Airborne Dust for Lead-Rich Phase Occurrence during Characterisation of Particle Mineralogy, Chemistry and Provenance: Application to Deposits in the Vicinity of an Integrated Steelworks

A method has been developed to screen large numbers (~103–104 per sample) of coarse airborne dust particles for the occurrence of Pb-rich phases, together with quantification of the particles’ mineralogy, chemistry, and inferred provenance. Using SEM-EDS spectral imaging (SI) at 15 kV, and processing with the custom software PARC, screening of individual SI pixels is performed for Pb at the concentration level of ~10% at a length-scale of ~1 µm. The issue of overlapping Pb-Mα and S-Kα signal is resolved by exploiting peak shape criteria. The general efficacy of the method is demonstrated on a set of NIST particulate dust standard reference materials (SRMs 1649b, 2580, 2584 and 2587) with variable total Pb concentrations, and applied to a set of 31 dust samples taken in the municipalities surrounding the integrated steelworks of Tata Steel in IJmuiden, the Netherlands. The total abundances of Pb-rich pixels in the samples range from none to 0.094 area % of the (total) particle surfaces. Overall, out of ca. 92k screened particles, Pb was found in six discrete Pb-phase dominated particles and, more commonly, as superficial sub-particles (sub-micron to 10 µm) adhering to coarser particles of diverse and Pb-unrelated provenance. No relationship is apparent between the samples’ Pb-rich pixel abundance and their overall composition in terms of particle provenance.

Evaluation of Fine and Ultrafine Particles Proportion in Airborne Dust in an Industrial Area

The health impacts of suspended particulate matter (SPM) are significantly associated with size—the smaller the aerosol particles, the stronger the biological effect. Quantitative evaluation of fine and ultrafine particles (FP and UFP) is, therefore, an integral part of ongoing epidemiological studies. The mass concentrations of SPM fractions (especially PM2.5, PM1.0, PM0.25) were measured in an industrial area using cascade personal samplers and a gravimetric method, and their mass ratio was determined. The results of PM2.5, PM1.0 were also compared with the reference measurement at stationary stations. The mean ratios PM2.5/SPM, PM1.0/SPM, and PM1.0/PM2.5 were 0.76, 0.65, and 0.86, respectively. Surprisingly, a mass dominance of UFP with an aerodynamic diameter <0.25 μm (PM0.25) was found with mean ratios of 0.43, 0.57, 0.67 in SPM, PM2.5 and PM1.0. The method used showed satisfactory agreement in comparison with reference measurements. The respirable fraction may consist predominantly of UFP. Despite the measures currently being taken to improve air quality, the most biologically efficient UFP can escape and remain in the air. UFP are currently determined primarily as particle number as opposed to the mass concentration used for conventional fractions. This complicates their mutual comparison and determination of individual fraction ratios.

Numerical Simulation of Tehran Dust Storm on 2 June 2014: A Case Study of Agricultural Abandoned Lands as Emission Sources

On 2 June 2014, at about 13 UTC, a dust storm arrived in Tehran as a severe hazard that caused injures, deaths, failures in power supply, and traffic disruption. Such an extreme event is not considered as common for the Tehran area, which has raised the question of the dust storm’s origin and the need for increasing citizens’ preparedness during such events. The analysis of the observational data and numerical simulations using coupled dust-atmospheric models showed that intensive convective activity occurred over the south and southwest of Tehran, which produced cold downdrafts and, consequently, high-velocity surface winds. Different dust source masks were used as an input for model hindcasts of the event (forecasts of the past event) to show the capability of the numerical models to perform high-quality forecasts in such events and to expand the knowledge on the storm’s formation and progression. In addition to the proven capability of the models, if engaged in operational use to contribute to the establishment of an early warning system for dust storms, another conclusion appeared as a highlight of this research: abandoned agricultural areas south of Tehran were responsible for over 50% of the airborne dust concentration within the dust storm that surged through Tehran. Such a dust source in the numerical simulation produced a PM10 surface dust concentration of several thousand μm/m3, which classifies it as a dust source hot-spot. The produced evidence indivisibly links issues of land degradation, extreme weather, environmental protection, and health and safety.