Negative Ion Purifier Effects on Indoor Particulate Dosage to Small Airways

Abstract

Indoor air quality is an important health factor as we spend more than 80% of our time indoors. The primary type of indoor pollutant is particulate matter, high levels of which increase respiratory disease risk. Therefore, air purifiers are a common choice for addressing indoor air pollution. Compared with traditional filtration purifiers, negative ion air purifiers (NIAPs) have gained popularity due to their energy efficiency and lack of noise. Although some studies have shown that negative ions may offset the cardiorespiratory benefits of air purifiers, the underlying mechanism is still unclear. In this study, we conducted a full-scale experiment using an in vitro airway model connected to a breathing simulator to mimic inhalation. The model was constructed using computed tomography scans of human airways and 3D-printing technology. We then quantified the effects of NIAPs on the administered dose of 0.5–2.5 μm particles in the small airway. Compared with the filtration purifier, the NIAP had a better dilution effect after a 1-h exposure and the cumulative administered dose to the small airway was reduced by 20%. In addition, increasing the negative ion concentration helped reduce the small airway exposure risk. NIAPs were found to be an energy-efficient air purification intervention that can effectively reduce the small airway particle exposure when a sufficient negative ion concentration is maintained.

Negative air ions through the action of antioxidation, anti-inflammation, anti-apoptosis and angiogenesis ameliorate lipopolysaccharide induced acute lung injury and promote diabetic wound healing in rat

“…They found that the increased NAIs associated with the decreased PM improved respiratory function mainly by eight pathways including promoting energy production, anti-inflammation and anti-oxidation capacity [ 31 ]. NAIs were also observed to be an energy-efficient air purification intervention that can effectively reduce the small airway particle exposure when a sufficient NAIs concentration is obtained [ 32 ]. ALI is a syndrome of pulmonary inflammation and permeability characterized by gas exchange dysfunction associated with pathological features like pulmonary capillary endothelial cell damage, alveolar epithelial cell injury, extensive aqualung, tiny pulmonary atelectasis, microthrombi and microcirculation disturbance [ 10 ].…”

Protocol of a randomised controlled trial to assess medical staff’s inhalation exposure to infectious particles exhaled by patients during oesophagogastroduodenoscopy and the efficacy of surgical masks in this context

“…All of the rooms will be ventilated in a manner similar to that used in our previous study (such as in terms of relative parameters, airflow organisation and the location of the diffusers and purifier). 46 The specific environments of rooms will be adjusted to suit the actual conditions of this RCT.…”

“…The anthropomorphic model will be placed at a fixed position beside the participant to simulate an endoscopist. The distance from the oral cavity of the participant to the oral cavity of the anthropomorphic model will be 0.8±0.1 m,45 46 and the anthropomorphic model will wear or not wear a surgical mask, according to the group allocation of the participant being examined.…”

“…The slices were processed with commercial software (Intrasense Myrian V1.12, France) to extract and restore the three-dimensional regions of interest. Please see our previous studies for detailed processes and model information 45 46. The facial mucosal deposition dosage and small airway inhalation dosage to infectious particles can be collected and sampled.…”

Optimization of COVID-19 prevention and control with low building energy consumption

“…People use various non-pharmaceutical interventions (NPI) (e.g. indoor ventilation, air purifiers, ultraviolet, and masking) to reduce the infection risk of COVID-19, with increasing the fresh air exchange rate being the most popular intervention [ [6] , [7] , [8] , [9] ]. However, excessive ventilation inevitably wastes energy, particularly on hot or cold days.…”