2020
Yes
https://www.sciencedirect.com/science/article/pii/S0048969720318738
Kumar, Prashant
Europe
Experimental
High School (9-12)
Carbon Dioxide (CO2)
Particulate Matter (PM)
Citizen science
Smart citizen kids
Community engagement
Air pollution exposure
Iscape project
Based on the findings of this exercise, the following conclusions are drawn:
•
Fine particles were found to be the dominant size fraction in the school environment. The line source owing to cars' queuing affected all the SPs, where PM2.5 concentrations during MP hours were 1.5–2.6 times higher than OP hours. The average fine to coarse particle concentration ratios were always >2 at all SPs, indicating that the exhaust emissions from idling cars elevated the base PM2.5 concentrations.
•
The time series of fine and coarse particles during MP and EP hours showed a pattern with a strong association with traffic congestion hours. Children are exposed to much higher levels of PM2.5 during drop-off than pick-up hours, partly also the drop-off point is closer to the school doorstep than the pick-up point. The average concentrations of PM2.5 were about 3-times higher than those during OP and EP hours.
•
Dust re-suspension was a probable reason for the substantial contribution of coarse particles in the school playground where the ratio of SP5/SP1 was >1. However, the school playground was impacted by PM2.5 from the local traffic during drop-off hours, which is alarming for daily outdoor activities. The study showed that the concentration of fine particles at the playground was equal to the Epsom Road (SP1) during MP hours. Significantly lower PM2.5 ratios were observed at the playground during OP (12%) and EP (24%) hours compared to MP hours. Additional barriers in the adjoining road should be considered to tackle vehicular emissions.
•
Inadequate fresh air supply is a characteristic of naturally ventilated classrooms, which rely on the status of doors/windows and occupancies. In the case of PM2.5 concentration, the correlation of 0.58 and 0.67 was found between in-class air quality and the ambient environment during drop-off/pick-up hours, respectively. This indicated that IAQ in the naturally ventilated classroom is correlated to varying degrees with unfiltered outdoor air.
•
I/O PM2.5 concentration ratio was less than one during drop-off hours. This could be due to the release of fresh PM2.5 from idling vehicles at drop-off zone, PM2.5 ingress through intermittent opening of the door towards the drop-off zone; and the absence of indoor sources (seldom occupancy during drop-off hours). The study revealed that there is a trade-off between controlling infiltration of vehicular PM2.5 and maintaining thermal comfort during class occupancy in a naturally ventilated classroom. Among the three monitored periods during the school hours, EP recorded the highest average I/O ratio for CO2 (2.8 ± 0.4), followed by OP (2.7 ± 0.6) and then MP (1.7 ± 0.5) hours. These results imply that ingress of exhaust PM emissions from idling cars via the external door and windows during drop-off/pick-up hours could be avoided, possibly by keeping the door and windows on that exposed side of the room closed as much as possible during MP and EP hours and making better use of the internal door and windows in the adjoining corridor space which can draw on relatively cleaner air from the other side of the classroom block which faces away from the road and drop-off point.
•
Fine particles were found to be the dominant size fraction in the school environment. The line source owing to cars' queuing affected all the SPs, where PM2.5 concentrations during MP hours were 1.5–2.6 times higher than OP hours. The average fine to coarse particle concentration ratios were always >2 at all SPs, indicating that the exhaust emissions from idling cars elevated the base PM2.5 concentrations.
•
The time series of fine and coarse particles during MP and EP hours showed a pattern with a strong association with traffic congestion hours. Children are exposed to much higher levels of PM2.5 during drop-off than pick-up hours, partly also the drop-off point is closer to the school doorstep than the pick-up point. The average concentrations of PM2.5 were about 3-times higher than those during OP and EP hours.
•
Dust re-suspension was a probable reason for the substantial contribution of coarse particles in the school playground where the ratio of SP5/SP1 was >1. However, the school playground was impacted by PM2.5 from the local traffic during drop-off hours, which is alarming for daily outdoor activities. The study showed that the concentration of fine particles at the playground was equal to the Epsom Road (SP1) during MP hours. Significantly lower PM2.5 ratios were observed at the playground during OP (12%) and EP (24%) hours compared to MP hours. Additional barriers in the adjoining road should be considered to tackle vehicular emissions.
•
Inadequate fresh air supply is a characteristic of naturally ventilated classrooms, which rely on the status of doors/windows and occupancies. In the case of PM2.5 concentration, the correlation of 0.58 and 0.67 was found between in-class air quality and the ambient environment during drop-off/pick-up hours, respectively. This indicated that IAQ in the naturally ventilated classroom is correlated to varying degrees with unfiltered outdoor air.
•
I/O PM2.5 concentration ratio was less than one during drop-off hours. This could be due to the release of fresh PM2.5 from idling vehicles at drop-off zone, PM2.5 ingress through intermittent opening of the door towards the drop-off zone; and the absence of indoor sources (seldom occupancy during drop-off hours). The study revealed that there is a trade-off between controlling infiltration of vehicular PM2.5 and maintaining thermal comfort during class occupancy in a naturally ventilated classroom. Among the three monitored periods during the school hours, EP recorded the highest average I/O ratio for CO2 (2.8 ± 0.4), followed by OP (2.7 ± 0.6) and then MP (1.7 ± 0.5) hours. These results imply that ingress of exhaust PM emissions from idling cars via the external door and windows during drop-off/pick-up hours could be avoided, possibly by keeping the door and windows on that exposed side of the room closed as much as possible during MP and EP hours and making better use of the internal door and windows in the adjoining corridor space which can draw on relatively cleaner air from the other side of the classroom block which faces away from the road and drop-off point.