Science Inventory

HEPA filtration intervention in classrooms may improve some students' asthma

Citation:

Vesper, S., L. Wymer, B. Coull, P. Koutrakis, A. Cunningham, C. Petty, N. Metwali, W. Sheehan, J. Gaffin, P. Permaul, P. Lai, L. Bartnikas, M. Hauptman, D. Gold, S. Baxi, AND W. Phipatanakul. HEPA filtration intervention in classrooms may improve some students' asthma. Journal of Asthma. Informa Healthcare, London, Uk, 60(3):479-486, (2023). https://doi.org/10.1080/02770903.2022.2059672

Impact/Purpose:

Asthma is the most common chronic disease of children in the US. Mold exposures have been linked to asthma development and exacerbation. In this study, mold levels in students' classroom and their home were compared. High-efficiency particulate (HEPA) filtration was used in classrooms to reduce mold levels. If the mold levels in the classroom was greater than in the home, HEPA filtration in the classroom resulted in improvements to the students' asthma symptoms. Reducing childhood mold exposures can result in reducing asthma symptoms. EPA's Office of Children's Health protection might be interested in these results. It is hoped that parents and schools might be able to apply the lessons learned,

Description:

Objective: The School Inner-City Asthma Intervention Study 2 (SICAS 2) tested interventions to reduce exposures in classrooms of students with asthma. The objective of this post-hoc analysis was limited to evaluating the effect of high-efficiency particulate (HEPA) filtration interventions on mold levels as quantified using the Environmental Relative Moldiness Index (ERMI) and the possible improvement in the students' asthma, as quantified by spirometry testing. Methods: Pre-intervention dust samples were collected at the beginning of the school year from classrooms and corresponding homes of students with asthma (n = 150). Follow-up dust samples were collected in the classrooms at the end of the HEPA or Sham intervention. For each dust sample, ERMI values and the Group 1 and Group 2 mold levels (components of the ERMI metric) were quantified. In addition, each student's lung function was evaluated by spirometry testing, specifically the percentage predicted forced expiratory volume at 1 sec (FEV1%), before and at the end of the intervention. Results: For those students with a higher Group 1 mold level in their pre-intervention classroom than home (n = 94), the FEV1% results for those students was significantly (p < 0.05) inversely correlated with the Group 1 level in their classrooms. After the HEPA intervention, the average Group 1 and ERMI values were significantly lowered, and the average FEV1% test results significantly increased by an average of 4.22% for students in HEPA compared to Sham classrooms. Conclusions: HEPA intervention in classrooms reduced Group 1 and ERMI values, which corresponded to improvements in the students' FEV1% test results.