School Environmental Intervention to Reduce Particulate Pollutant Exposures for Children with Asthma

Abstract

Background Home-based interventions to improve indoor air quality have demonstrated benefits for asthma morbidity, yet little is known about the effect of environmental interventions in the school setting. Objective We piloted the feasibility and effectiveness of a classroom-based air cleaner intervention to reduce particulate pollutants in classrooms of children with asthma. Methods In this pilot randomized controlled trial, we assessed the effect of air cleaners on indoor air particulate pollutant concentrations in 18 classrooms (9 control, 9 intervention) in 3 urban elementary schools. We enrolled 25 asthmatic children (13 control, 12 intervention) aged 6–10 years old. Classroom air pollutant measurements and spirometry were completed once prior to and twice after randomization. Asthma symptoms were surveyed every 3 months. Results Baseline classroom levels of fine particulate matter (PM2.5) and black carbon (BC) were 6.3 μg/m3 and 0.41 μg/m3, respectively. When comparing the intervention to the control group, classroom PM2.5 levels were reduced by 49% and 42%, and BC levels were reduced by 58% and 55% in the first and second follow-up periods, respectively (p < 0.05 for all comparisons). When comparing the children randomized to intervention and control classrooms, there was a modest improvement in peak flow, but no significant changes in forced expiratory volume in 1 second (FEV1) and asthma symptoms. Conclusion In this pilot study, a classroom-based air cleaner intervention led to significant reductions in PM2.5 and BC. Future large-scale studies should comprehensively evaluate the effect of school-based environmental interventions on pediatric asthma morbidity.

The School Inner-City Asthma Intervention Study: Design, rationale, methods, and lessons learned

“…[5] We then piloted in a school-based setting that we could feasibly bring down asthma-based triggers in schools. [16] This utilized classroom-suitable HEPA air filters[16] specifically adapted to maximize flow while minimizing noise.…”

“…To achieve maximum effectiveness with an acceptable noise level (52db), custom modification was made to get a dust-free air delivery rate (CADR) of 106 ft[3]/min (CFM). The air filtration system is designed for rooms up to 400 ft,[2] was effective in reducing particles in our Pilot (4 filters/classroom),[16] and was well-received in the classroom/school setting.…”

“…[14,15] We then demonstrated that we could effectively decrease classroom-specific toxic exposures during the academic school year by utilizing classroom-suitable High Efficiency Particulate Air (HEPA) air filters specifically adapted to maximize flow while minimizing noise. [16]…”

Advances in environmental and occupational disorders in 2016

“…Finally, there is opportunity for environmental intervention studies outside of the home. Jhun et al(78) demonstrated that classroom-based air cleaners led to significant reductions in PM 2.5 and black carbon when compared to control classrooms. This highlights the school as a location for future environmental intervention studies aimed at improving asthma in children.…”

NIAID, NIEHS, NHLBI, and MCAN Workshop Report: The indoor environment and childhood asthma—implications for home environmental intervention in asthma prevention and management

“…(61) Other than replacement of gas stoves with electric stoves, fewer methods are currently available for indoor NO 2 reduction of indoor or outdoor origin. (62, 63) In homes with smokers, recent home and school-based intervention trials in children report significant reductions in particulate matter with HEPA filter use, (64–66) but without reduction in indoor gases, without consistent reductions in markers of cigarette smoke, and with mixed success in improving child asthma symptoms. The efficacy in reducing indoor pollutants is dependent on room dimensions and building structure and conditions.…”