Indoor air filtration could lead to increased airborne endotoxin levels

[Display omitted] •Airborne endotoxins increased in the air filtered through a previously used HEPA-air-purifier.•Replacement of HEPA helped to mitigate the risk of increased endotoxins in larger size.•Broken bacteria on the HEPA contributed to the increase of endotoxins. Stand-alone portable air pu...

Full description

Saved in:
Bibliographic Details
Published in:Environment international 2020-09, Vol.142, p.105878, Article 105878
Main Authors: Niu, Mutong, Shen, Fangxia, Zhou, Feng, Zhu, Tianle, Zheng, Yunhao, Yang, Yi, Sun, Ye, Li, Xinghua, Wu, Yan, Fu, Pingqing, Tao, Shu
Format: Article
Language:English
Subjects:
Air Filters
Air Pollution, Indoor - analysis
Air purifier
Bacteria
Bioaerosols
Dust
Endotoxins
Health effects
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •Airborne endotoxins increased in the air filtered through a previously used HEPA-air-purifier.•Replacement of HEPA helped to mitigate the risk of increased endotoxins in larger size.•Broken bacteria on the HEPA contributed to the increase of endotoxins. Stand-alone portable air purifiers (APs) have become an increasingly popular method of controlling individual inhalation exposure. Exposure to bacterial endotoxins has a causative role in respiratory inhalation health. Here, we studied the changes in endotoxin levels in indoor air before and after purification by a portable AP equipped with HEPA (high-efficiency particulate air) filters. An increase in endotoxins was observed when a previously used AP was turned on to clean the air. Replacing the HEPA filters in the AP helped to mitigate the increase in endotoxins of larger sizes but not endotoxins of smaller sizes. Consequently, the use of APs could lead to increased endotoxin deposition in airways, especially in the alveolar region. The endotoxin concentrations on the HEPA filters were well correlated with the free DNA concentrations on the HEPA filters. This correlation indicates that the disrupted bacteria, which released free DNA, could also release endotoxins, thus making HEPA filters a source of indoor airborne endotoxins. Our results illustrate a potential endotoxin inhalation risk associated with HEPA-APs as an air cleaning strategy and highlight the importance of composition-specific air cleaning while reducing the particle number/mass.
ISSN:0160-4120
1873-6750
DOI:10.1016/j.envint.2020.105878