Negative ions offset cardiorespiratory benefits of PM2.5 reduction from residential use of negative ion air purifiers.
Indoor Air
; 31(1): 220-228, 2021 01.
Article
em En
| MEDLINE
| ID: mdl-32757287
ABSTRACT
Negative ion air purifiers (NIAPs), as a less costly alternative to the HEPA filtration, have been increasingly deployed in China and potentially elsewhere. While reducing indoor concentrations of fine particulate matter (PM2.5 ), NIAPs generate massive amounts of negative ions that may be of health concern. We performed week-long interventions with NIAPs in the dormitories of 56 healthy college students living in Beijing. In a randomized order, each student underwent a true and a sham NIAP session. Cardiorespiratory outcomes were measured before and after each session. The use of true NIAPs reduced indoor PM2.5 concentrations significantly, while notably increased negative ion levels. Increases in PM2.5 and negative ion (NI) exposure were independently associated with increased urinary concentration of malondialdehyde, a biomarker of systemic oxidative stress, resulting in a null net effect of NIAP on malondialdehyde. Likewise, no significant net effects of NIAPs were observed for other outcomes indicative of lung function, vascular tone, arterial stiffness, and inflammation. Our findings suggest that negative ions, possibly along with their reaction products with the room air constituents, adversely affect health. The downsides do not support the use of NIAPs as a health-based mitigation strategy to reduce PM2.5 exposure, especially in residences with PM2.5 concentrations that are not extremely high.
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Base de dados:
MEDLINE
Assunto principal:
Monitoramento Ambiental
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Poluição do Ar em Ambientes Fechados
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Material Particulado
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Filtros de Ar
Tipo de estudo:
Clinical_trials
Limite:
Adult
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Humans
País como assunto:
Asia
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article