Detection of SARS-CoV-2 in the indoor air and surfaces of subway trains in Mashhad, Iran.

INTRODUCTION: Millions of passengers around the world are concerned with the possibility of SARS-CoV-2 contamination on public transportation. Therefore, this study aimed to investigate the presence of SARS-CoV-2 virus in indoor air and subway surfaces in Mashhad. METHODS: In this study, air and surface sampling were done at two times in the morning (7-8:30 a.m.) and evening (3:30-5 p.m.), simultaneously in two wagons for men and women in line 1 of Mashhad Metro in March 2021 to detect the virus and measure the concentration of particulate matter. Totally, 30 air and 30 metro samples were collected and examined by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: The results showed that three and two cases in the air and surface samples were infected with the SARS-CoV-2 virus, respectively. There was a significant relationship between the mean concentration of suspended particles PM1 (particulate matter smaller than 1 µm) with PM2.5 (particulate matter smaller than 2.5 µm) and PM10 (particulate matter smaller than 10 µm) (p < 0. 05). There was also a significant relationship between the mean concentration of suspended particles PM2.5 and PM10. The results showed that the mean PM2.5 measured in the indoor air of the Mashhad metro wagon had a significant relationship with WHO and US EPA and national standards, and its value was higher than the standards (p < 0.05). The average particle concentrations of PM1, PM2.5, and PM10 were equal to 40.46, 42.61, and 48.31 µg/m3. CONCLUSION: According to the results of the pollution detected in this study, COVID-19 may be transmitted by air and environmental surfaces. Our study emphasizes the need for continuous assessment of the presence of the virus in public transportation. Detection of viral RNA in subways indicates the necessity of adequate disinfection in public settings, strictness in disinfection methods, strengthening of educational activities for sanitary measures, physical spacing plan, and increasing ventilation of wagons.

Sequential SEM-EDS, PLM, and MRS Microanalysis of Individual Atmospheric Particles: A Useful Tool for Assigning Emission Sources.

In this work, the particulate matter (PM) from three different monitoring stations in the Monterrey Metropolitan Area in Mexico were investigated for their compositional, morphological, and optical properties. The main aim of the research was to decipher the different sources of the particles. The methodology involved the ex situ sequential analysis of individual particles by three analytical techniques: scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), polarized light microscopy (PLM), and micro-Raman spectroscopy (MRS). The microanalysis was performed on samples of total suspended particles. Different morphologies were observed for particles rich in the same element, including prismatic, spherical, spheroidal, and irregular morphologies. The sequential microanalysis by SEM-EDS/PLM/MRS revealed that Fe-rich particles with spherical and irregular morphologies were derived from anthopogenic sources, such as emissions from the metallurgical industry and the wear of automobile parts, respectively. In contrast, Fe-rich particles with prismatic morphologies were associated with natural sources. In relation to carbon (C), the methodology was able to distinguish between the C-rich particles that came from different anthopogenic sources-such as the burning of fossil fuels, biomass, or charcoal-and the metallurgical industry. The optical properties of the Si-rich particles depended, to a greater extent, on their chemical composition than on their morphology, which made it possible to quickly and accurately differentiate aluminosilicates from quartz. The methodology demonstrated in this study was useful for performing the speciation of the particles rich in different elements. This differentiation helped to assign their possible emission sources.

Comparative mutagenic activity of atmospheric particulate matter from limeira, stockholm, and kyoto.

Atmospheric particulate matter (PM) organic fractions from urban centers are frequently mutagenic for the Salmonella/microsome assay. This mutagenicity is related to both primary and secondary pollutants, and meteorological conditions have great influence on the secondary pollutant's formation. Our objective was to compare the mutagenicity of atmospheric total suspended particulates (TSP) from three cities with marked different meteorological conditions and TSP concentrations: Limeira (Brazil) with 99.0 µg/m3 , Stockholm (Sweden) with 6.2 µg/m3 , and Kyoto (Japan) with 28.0 µg/m3 . For comparison, we used the same batch of filters, sample extraction method, and Salmonella/microsome testing protocol with 11 strains of Salmonella with and without metabolic activation. Samples were collected during winter and pooled into one single extract representing each city. All samples were mutagenic for all tested strains, except for TA102. Based on the strain's selectivity, nitroarenes, polycyclic aromatic hydrocarbons, and aromatic amines play a predominant role in the mutagenicity of these samples. The mutagenic potencies expressed by mass of extracted organic material (EOM; revertants/µg EOM) were similar (~twofold difference) among the cities, despite differences in meteorological conditions and pollution sources. In contrast, the mutagenic potencies expressed by air volume (rev/m3 ) varied ~20-fold, with Limeira > Kyoto ≈ Stockholm. These results are the first systematic assessment of air mutagenicity from cities on three continents using the same protocols. The results confirm that the mutagenic potency expressed by EOM mass is similar regardless of continent of origin, whereas the mutagenic potency expressed by air volume can vary by orders of magnitude. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.

Chemical composition modulates the adverse effects of particles on the mucociliary epithelium

OBJECTIVE:We compared the adverse effects of two types of real ambient particles; i.e., total suspended particles from an electrostatic precipitator of a steel mill and fine air particles from an urban ambient particulate matter of 2.5 µm, on mucociliary clearance.METHOD:Mucociliary function was quantified by mucociliary transport, ciliary beating frequency and the amount of acid and neutral mucous in epithelial cells through morphometry of frog palate preparations. The palates were immersed in one of the following solutions: total suspended particles (0.1 mg/mL), particulate matter 2.5 µm 0.1 mg/mL (PM0.1) or 3.0 mg/mL (PM3.0) and amphibian Ringer’s solution (control). Particle chemical compositions were determined by X-ray fluorescence and gas chromatography/mass spectrometry.RESULTS:Exposure to total suspended particles and PM3.0 decreased mucociliary transport. Ciliary beating frequency was diminished by total suspended particles at all times during exposure, while particulate matter of 2.5 µm did not elicit changes. Particulate matter of 2.5 µm reduced epithelial mucous and epithelium thickness, while total suspended particles behaved similarly to the control group. Total suspended particles exhibited a predominance of Fe and no organic compounds, while the particulate matter 2.5 µm contained predominant amounts of S, Fe, Si and, to a lesser extent, Cu, Ni, V, Zn and organic compounds.CONCLUSION:Our results showed that different compositions of particles induced different airway epithelial responses, emphasizing that knowledge of their individual characteristics may help to establish policies aimed at controlling air pollution.

Informing effective smokefree policies in Argentina: air quality monitoring study in 15 cities (2007-2009) / Políticas efectivas de ambientes libres de humo de tabaco en Argentina: estudio de monitoreo de calidad del aire en 15 ciudades (2007-2009)

Objective. To evaluate indoor air pollution in hospitality venues in Argentina. Material and Methods. PM2.5 levels were measured in a convenience sample of venues in 15 cities with different legislative contexts following a protocol developed by Roswell Park Cancer Institute. Results. 554 samples were collected. Across all 5 smokefree cities the mean PM2.5 level was lower during daytime vs. evening hours, 24 vs. 98 PM2.5 respectively (p=.012). In the three cities evaluated before and after legislation, PM2.5 levels decreased dramatically (p<0.001 each). Overall, PM2.5 levels were 5 times higher in cities with no legislation vs. smokefree cities (p<0.001). In cities with designated smoking areas, PM2.5 levels were not statistically different between smoking and non-smoking areas (p=0.272). Non-smoking areas had significantly higher PM2.5 levels compared to 100 percent smokefree venues in the same city (twofold higher) (p=0.017). Conclusions. Most of the participating cities in this study had significantly lower PM2.5 levels after the implementation of 100 percent smokefree legislation. Hence, it represents a useful tool to promote 100 percent smokefree policies in Argentina.

Objetivo. Evaluar la polución ambiental del sector gastronómico en Argentina. Material y métodos. Se midieron los niveles de partículas respirables (PM2.5) en una muestra por conveniencia de establecimientos de 15 ciudades con diferente legislación, siguiendo un protocolo del Instituto de Cáncer Roswell Park. Resultados. Se recolectaron 554 muestras. En cinco ciudades libres de humo (CLH) la media de PM2.5 durante el día fue baja y menor a la observada durante la noche, 24 vs. 98 PM2.5 respectivamente (p=.012). En las tres ciudades evaluadas antes y después de la legislación, las PM2.5 disminuyeron drásticamente (p<0.001 cada una). Las PM2.5 fueron cinco veces mayores en ciudades sin legislación comparadas con CLH (p<0.001). En ciudades con restricción parcial, no hubo diferencia significativa entre las PM2.5 en el sector fumador y no fumador (p=0.272). Los sectores no fumadores tuvieron niveles PM2.5 significativamente más altos comparados con los lugares 100 por ciento libres de humo de la misma ciudad (p= 0.017). Conclusiones. La mayoría de las ciudades participantes en este estudio tuvieron niveles PM2.5 significativamente más bajos tras la implementación de leyes pro ambientes 100 por ciento libres de humo de tabaco, por lo que representa una herramienta útil para promover legislación 100 por ciento libre de humo en Argentina.

Efectos de la contaminación atmosférica sobre la salud de adultos que laboran en diferentes niveles de exposición / Air pollution and its effects in adults working at different levels of exposure

Objetivo: evaluar las diferencias en las condiciones de salud entre grupos de trabajadores expuestos, no expuestos y menos expuestos a contaminación ambiental en el área metropolitana del valle de Aburrá. Métodos: se realizó una cuidadosa revisión de las mediciones de contaminantes ambientales, precipitación, temperatura y variables demográficas y sociales de los municipios del área metropolitana del Valle del Aburrá y del oriente del departamento de Antioquia (Colombia). Se realizó un estudio transversal de corte. Se seleccionó aleatoriamente una población de 3.500 habitantes. A los individuos seleccionados se les aplicó una encuesta previamente estandarizada y se les estudiaron las pruebas funcionales respiratorias mediante espirometría. Resultados: se realizaron 400 espirometrías. No se encontraron diferencias significativas entre los dos grupos en cuanto a edad, sexo, consumo de cigarrillo y estrato socioeconómico. Las partículas suspendidas totales (PST) están frecuentemente por encima de 100 µg/m³. Igual sucede con material particulado inferior a 10 micras (PM10). Los no expuestos tienen una mejor relación volumen expiratorio forzado en el primer segundo sobre capacidad vital forzada (VEF1/CVF), en 3,1%. Se evidenció un exceso de riesgo de sufrir afecciones obstructivas pulmonares entre los expuestos frente a los no expuestos de 68% RR 1,68 IC (1,19-2,36). Conclusiones: la calidad del aire del área metropolitana del Valle del Aburrá no es buena. Hay un exceso de riesgo en los expuestos a contaminación de sufrir afecciones obstructivas pulmonares.

Objective: to test the differences in health conditions between groups of exposed and non exposed workers to environmental pollution in the metropolitan area of Aburrá Valley. Methods: a careful revision of the measurements of environmental pollution agents, precipitation, temperature and sociodemographic variables of the municipalities of the metropolitan area of Aburrá Valley and the eastern region of the department of Antioquia (Colombia) was accomplished. A cross-sectional study was made. A random selection of a population of 3.500 inhabitants was done. A previously standardized survey was applied to selected individuals and respiratory functional tests were also administered to them by means of spirometry. Results: four hundred spirometries were made. Non significant differences between the two groups were found according to age, sex, smoking habit, consumption and socioeconomic level. Total suspended particles are over 100 µg/m³ and the same applies to the PM10. The workers not exposed have a better relation VEF1/VCF (3.1%). A high risk excess to suffer lung obstructive affections between non exposed workers vs. exposed workers: 68%, RR 1,68 IC (1,19-2,36). Conclusion: air quality in the metropolitan area of Aburrá Valley is not good. There is a risk excess in people exposed to pollution of suffering lung obstructive affections.

Contaminación del aire interior en un proyecto de viviendas con climatización centralizada / Indoor air pollution in a housing project fitted with central air-conditioning

La contaminación del aire interior de las viviendas ejerce una importante influencia sobre la salud de la población y grupos de riesgo, a pesar de lo cual resultan escasos los estudios realizados en Cuba. Se efectuó un estudio descriptivo en un apartamento de un prototipo de edificio típico de viviendas con climatización centralizada. Durante cinco días consecutivos se determinaron las concentraciones sincrónicas horarias de dióxido de nitrógeno (NO2 ) en la cocina y la sala de la vivienda y en el exterior de esta, con la cocina de gas apagada y posteriormente encendida, así como las medias diarias de dióxido de azufre (SO2 ) y partículas en suspensión totales (PST) en la sala y en el exterior. La climatización se mantuvo en la mínima capacidad de enfriamiento y las ventanas cerradas. Las concentraciones medias diarias de SO2 en el interior de la vivienda resultaron superiores a las registradas de forma sincrónica en el exterior, en tanto que para las PST ocurrió lo inverso. En ambos casos los valores observados fueron inferiores a las concentraciones máximas admisibles. Con el encendido de la cocina de gas se produjo un incremento de las concentraciones horarias de NO2 en el interior de la vivienda, las que superaron la concentración máxima admisible. La acumulación de NO2 demostró la insuficiente tasa de renovación del aire interior contaminado por parte del sistema de climatización, el escaso aprovechamiento de la ventilación natural y la dudosa sostenibilidad ambiental del diseño. Se formularon recomendaciones.

Indoor air pollution in dwellings heavily influences the population´s and the risk groups´ health. Despite this, few studies have been conducted on this topic in Cuba. A descriptive study was carried out in an apartment located in a typical building prototype fitted with central air-conditoning. For five days, synchronic hourly nitrogen dioxide (NO2) concentrations were measured in the kitchen and the living room as well as outdoors, with the gas stove out and later ignited whereas daily sulphur dioxide means (SO2) and total suspended particles were determined the living room and outdoors. Air-conditioning was kept at the minimun cooling rating and the windows remained closed. Daily mean concentrations of S02 inside the house exceeded those recorded outdoor whereas it was the opposite in TSP. The estimated values in both cases were lower than the allowable maximum concentrations. The ignition of the gas stove brought about higher hourly N02 concentrations inside the house, which were over the allowable maximum concentrations. Accumulated N02 confirmed the inadequate rate of polluted indoor air exchange by the air-conditioned system, the underutilization of natural ventilation and the unclear environmental sustainability of the design. Finally, recommendations were made.