Investigation of air pollution mitigation measures, ventilation, and indoor air quality at three schools in London

In UK urban areas, due to ease of accessibility and convenience, many schools are located close to main busy roads. This often results in pollution hotspots around schools due to on-road vehicular pollutant emissions, especially during drop-off and pick-up times of students to and from schools. As well as being exposed to air pollutants in the school grounds, students are also exposed indoors. Thus, the need for scientific investigations focusing on mitigation of air pollution exposure indoors and outdoors for schools has significantly increased. The main objectives of the present study were therefore to: 1) obtain a clearer understanding of the extent of the air pollution problem inside and around schools and the factors that affect it; and 2) determine how it may be mitigated effectively using a range of interventions. These were achieved by carrying out monitoring of air pollution and associated parameters in and around three primary schools in London, UK. The study investigated the exposure reduction potential of various interventions, such as green screens, air purifiers, and school streets. A good understanding was obtained of the improvement in air quality that was achieved by the interventions both inside and outside the classrooms in the three schools. A green screen along the fences of the school reduced PM concentration by up to 44% in the playground. Installing air purifiers in a classroom resulted in lowering in PM concentration of about 57%. The school street initiative decreased PM concentration by about 36% in front of the school during pick up time. From the overall findings, practical recommendations have been included, as far as has been possible, that will enable formal guidance to be produced to help improve air quality in and around UK schools.