Poor indoor air quality is an important issue for public and occupational health worldwide. Location, air-tightness of the building, ventilation rate and resident activities play an important role on the concentration of indoor pollutants and subsequently on their effects on human health. While indoor air pollution in working environments has been widely studied, the association between specific pollutants and Sick Building Syndrome (SBS) symptoms is still not clear. The objective of this study is to explore the association between PM2.5 and BC with SBS symptoms reported by employees working in a public building in the center of Athens, Greece. Continuous indoor air quality measurements were carried out from March until May 2016 (24 h, 7 days per week), including days during a Saharan dust event in March 2016. The measurements took place in four different types of spaces, including an office, a printer room and two archiving rooms, representing both high and low exposure environments. Indoor PM2.5 and BC concentrations in the office ranged from 5.9 to 14.3 μg/m3 and 1.1–1.9 μg/m3, respectively, whereas outdoor PM2.5 and BC concentrations were in the range of 6.5–21.7 μg/m3 and 1.4–2.6 μg/m3, respectively. We observed diurnal variations in indoor/outdoor ratios of PM2.5 and BC in most rooms that were >1 during working hours, that subsequently fell to below unity after working hours. Data collected via a questionnaire to 73 employees showed that the most commonly reported SBS symptoms were irritation of the eyes, a stuffy or runny nose, headache and drowsiness. Female employees were more likely to report SBS symptoms than male employees, especially nonspecific symptoms, including “unusual tiredness or fatigue” and “feeling depressed”.@en

The use of disc diffusion susceptibility tests to determine the antibacterial activity of engineered nanoparticles (ENPs) is questionable because their low diffusivity practically prevents them from penetrating through the culture media. In this study, we investigate the ability of such a test, namely the Kirby-Bauer disc diffusion test, to determine the antimicrobial activity of Au and Ag ENPs having diameters from 10 to 40 nm on Escherichia coli cultures. As anticipated, the tests did not show any antibacterial effects of Au nanoparticles (NPs) as a result of their negligible diffusivity through the culture media. Ag NPs on the other hand exhibited a strong antimicrobial activity that was independent of their size. Considering that Ag, in contrast to Au, dissolves upon oxidation and dilution in aqueous solutions, the apparent antibacterial behavior of Ag NPs is attributed to the ions they release. The Kirby-Bauer method, and other similar tests, can therefore be employed to probe the antimicrobial activity of ENPs related to their ability to release ions rather than to their unique size-dependent properties. [Figure not available: see fulltext.].@en

Poor air quality in workplaces constitutes a great concern on human health as a good fraction of our time is spent at work. In Greece, very unique workplaces are the street corner kiosks, which are freestanding boxes placed on sidewalks next to city streets and vehicular traffic, where one can find many consumer goods. As such, its employees are exposed to both outdoor and indoor air pollutants. Very few studies have examined the occupational exposure of kiosk workers to air pollutants, and thus the magnitude of this unique indoor and outdoor exposure remains unknown. The objective of this study is to investigate and compare the levels of indoor and outdoor particulate matter (PM10 and PM2.5), ultrafine particles (UFPs) and black carbon (BC) in different kiosks located in Athens, Greece, in urban-traffic and urban-background environments. Continuous measurements of the above-mentioned pollutants were carried out on a 24-h basis over 7 consecutive days at three kiosks from September to October 2019. Indoor PM10 concentrations in the urban kiosk ranged from 19.0 to 44.0 μg/m3, PM2.5 values ranged from 14.0 to 33.0 μg/m3, whereas BC concentrations ranged from 1.2 to 7.0 μg/m3 and UFPs from almost 9.5 to 47.0 × 103 pt/cm3. Outdoor PM10 and PM2.5 measurements ranged from 29.0 to 59.0 μg/m3 and from 22.0 to 39.0 μg/m3, respectively. BC outdoor concentrations ranged from 1.1 to 2.2 μg/m3. The mean hazard quotient (HQ) for PM10 (4.9) and PM2.5 (4.7) among all participants was >1. The health risk of exposure to PM10 and PM2.5 was found to be at moderate hazard levels, although in some cases we observed HQ values higher than 10 due to high PM10 and PM2.5 concentrations in the kiosks. Overall our study indicates that people working at kiosks can be exposed to very high concentrations on particulate pollution depending on a number of factors including the traffic that strongly depends on location and the time of the day.@en

As a growing percentage of the population is working in office buildings worldwide, air quality in these indoor environments is becoming of particular importance for assessing health impacts from exposure to different pollutants. Apart from the common indoor air pollution sources, the presence of a variety of electronics such as printers, copier machines and other equipment in office buildings may present a high health risk because of their emissions of gases and particles. The aim of this study is to review and compare available measurements of the most commonly reported indoor particulate matter (PM) fractions in office environments and the methodological approaches that were used for the assessment of air quality and associated health effects. Data from forty-nine studies conducted in twenty-four countries around the world were included in this review. Half of these studies report measurements of indoor air pollution concentrations at a fixed point, with half of those using portable devices for assessing the personal exposure of employees in a direct way. The results showed that indoor concentrations for all air pollutants were higher than those measured outdoors, and that they increased during working hours. The average PM levels in offices ranged from 14 to 333 μg/m 3 for particles having diameters up to 10 μm (PM 10 ), and 4–227.44 μg/m 3 for particles having diameters up to 2.5 μm (PM 2.5 ). Results also showed that many health effects like eye irritation, dry throat, runny nose, sneezing, cough, tiredness, irritability, difficulty concentrating, headache, dizziness, and skin irritation reported through questionnaires by employees were associated with these pollutants, while being influenced by gender and environmental factors such as temperature and relative humidity. @en

As a growing percentage of the population is working in office buildings worldwide, air quality in these indoor environments is becoming of particular importance for assessing health impacts from exposure to different pollutants. Apart from the common indoor air pollution sources, the presence of a variety of electronics such as printers, copier machines and other equipment in office buildings may present a high health risk because of their emissions of gases and particles. The aim of this study is to review and compare available measurements of the most commonly reported indoor particulate matter (PM) fractions in office environments and the methodological approaches that were used for the assessment of air quality and associated health effects. Data from forty-nine studies conducted in twenty-four countries around the world were included in this review. Half of these studies report measurements of indoor air pollution concentrations at a fixed point, with half of those using portable devices for assessing the personal exposure of employees in a direct way. The results showed that indoor concentrations for all air pollutants were higher than those measured outdoors, and that they increased during working hours. The average PM levels in offices ranged from 14 to 333 μg/m 3 for particles having diameters up to 10 μm (PM 10 ), and 4–227.44 μg/m 3 for particles having diameters up to 2.5 μm (PM 2.5 ). Results also showed that many health effects like eye irritation, dry throat, runny nose, sneezing, cough, tiredness, irritability, difficulty concentrating, headache, dizziness, and skin irritation reported through questionnaires by employees were associated with these pollutants, while being influenced by gender and environmental factors such as temperature and relative humidity. @en

The authors would like to replace <14. W03.31.000 > with <N075-15-2021-574> in the acknowledgement. We apologise for any inconvenience caused.@en

The increasing penetration of nano-products to the market is raising big concerns about the potential toxic and environmental effects of their constituent engineered nanoparticles (ENPs). Contradictory toxicity test results reported in the literature thus far can be explained by differences in the ENP production methods, which can strongly affect nanoparticle purity and therefore the outcome of the tests. In this paper we investigate the toxicity of Ag nanoparticles (AgNPs) produced by spark ablation - a gas-phase technique that can deliver well-defined nanoparticles of high purity - on Lemna minor. Our results show that AgNPs exhibit a toxic behavior at concentrations as low as 5 μg L−1, which is considerably lower compared to the threshold concentrations reported in other studies. This difference can be attributed to the purity of the ENPs used in our measurements, which can release higher concentrations of toxic Ag+ ions upon dilution in the test solutions.@en