The Effects of Negative Ion Indoor Air Filtration on Selected Biomarkers in Healthy Adults: A Randomized Double-Blind Crossover Trial

Abstract

Air pollution is a significant challenge in environmental health. According to the World Health Organization (WHO), about 91% of world’s population live in areas where WHO’s air quality guidelines were not met. Ambient air pollution causes approximately 4.2 million premature deaths worldwide. While outdoor ambient air quality is associated with global mortality, indoor air pollution also possesses a significant challenge to people’s health and well-being. In countries with less desirable air quality, the use of air filtration devices is common. Despite the rise of negative ion air filtration device usage, the purification efficiency and health effects of these devices remain unclear. The goal of this project is to evaluate health impacts of indoor negative ion air filtration intervention in healthy young adults. The intervention is hypothesized to reduce indoor fine particulate matter exposure and reduce adverse health effects associated with indoor PM2.5 pollution. We conducted a randomized, double-blind, cross-over study with two specific aims: first, to evaluate the effectiveness of PM2.5 removal by negative ion air filtration device; second, to evaluate differences in health endpoints associated with PM2.5 exposure between the two interventions. Fifty-five healthy adults participated in this study. Each participant received a random sequence of true and sham filtration intervention, with two weeks of washout period in between. Before and after each intervention period, these participants provided biological samples so we could measure specific biomarkers of interest to assess health impacts of each intervention. My project only assessed urinary biomarkers. Overall, only one out of the five biomarkers selected has statistically significant result. No significant difference between true and sham intervention is observed for urinary fMDA and (biomarkers of lipid peroxidation, reflecting cell membrane damage), 8-OHdG (a biomarker of oxidative damage to DNA), and 11-OHTXB1 (a biomarker of platelet activation, reflecting thrombosis risk). The findings indicate that the negative ion filtration did not lead to significant changes in biomarkers expected to be associated with fine particle exposure reduction. More research is needed to investigate other health endpoints and long-term changes associated with the use of negative ion air filtration device.