Indoor and outdoor air quality in street corner kiosks in a large metropolitan area

Abstract

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 PM_2.5), 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, PM_2.5 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 PM_2.5 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 PM_2.5 (4.7) among all participants was >1. The health risk of exposure to PM₁₀ and PM_2.5 was found to be at moderate hazard levels, although in some cases we observed HQ values higher than 10 due to high PM₁₀ and PM_2.5 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.