Work

Impacts of Portable Air Purifiers on the Oxidative Potential and Sources of Organic Matter in Indoor PM2.5

Year: 2024

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Organic matter (OM) is a major contributor to the oxidative potential (OP) of indoor PM 2.5 . Portable air purifiers equipped with high-efficiency particulate air (HEPA) filters are known to effectively remove indoor PM 2.5 mass concentrations. However, their impacts on the OP and sources of indoor PM 2.5 OM and whether these impacts could further affect the OP of indoor PM 2.5 metals remain poorly understood. In a crossover trial, each of the 43 asthmatic children underwent a 2-week true filtration (HEPA + activated carbon [AC]) and sham filtration (no HEPA + no AC), with randomized order. PM 2.5 samples, simultaneously collected in participants’ bedrooms and outside their homes, were measured for mass concentration, composition, mass-normalized OP (OP m, OP per mass), and volume-normalized OP (OP v, OP m × mass concentration). Compared to the sham filtration, indoor PM 2.5 OM mass was 34% lower, OP m was 70% lower, and OP v was 80% lower during true filtration. The reduction in OM OP v was largely attributed to removing more reactive outdoor OM and indoor secondary OM. The change in OM composition also contributed to the reduced PM 2.5 metals’ OP m . Our results suggest that indoor air purifiers with HEPA and AC filters efficiently reduce PM 2.5 OP v by removing OM.

Source: ACS ES&T Air

DOI: 10.1021/acsestair.4c00187