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. 2025 Apr;32(20):12360-12371.
doi: 10.1007/s11356-025-36441-0. Epub 2025 Apr 29.

Needle point bipolar ionization: environmental safety and inactivation of airborne bacteria and corona virus

Dila Aydın Aytekin  1 , Nurten Tetik  2 , Ülkü Alver Şahin  3 , Coşkun Ayvaz  1 , Elif Nurtop  4 , Cansel Vatansever  5 , Füsun Can  5   6
Affiliations

Needle point bipolar ionization: environmental safety and inactivation of airborne bacteria and corona virus

Dila Aydın Aytekin et al. Environ Sci Pollut Res Int. 2025 Apr.

Abstract

Although there is an increasing interest after the COVID-19 pandemic, electronic ionization efficiency and impact on indoor air quality are not yet fully understood, and studies are insufficient. Therefore, in this study, the disinfection efficiency for viruses and bacteria and the change of indoor thermal comfort parameters (temperature, humidity, pressure) and air pollutants (CO2, NO2, VOC, O3, CH2O, PM2.5, Particle Number (PN) from 0.3 to 10 µm particle sizes) by a portable indoor air cleaner using the needle point bipolar ionization (NPBI) method were investigated. The highest antibacterial activity was achieved at hour 3 with a 99.8% reduction for Bacillus subtilis, 99.8% for Staphylococcus aureus, 98.8% for Escherichia coli, and 99.4% for Staphylococcus albus, and sustained at hour 4th. The ions had antiviral activity on surfaces with a 94% TCID50 reduction of the HCoV-229E virus after 2 h of NPBI-on. No significant changes were detected in thermal comfort parameters, NO2, and VOC during the NPBI-on. Moreover, it was found that O3 and CH2O were not generated when the NPBI system was operated in the room for 4 h. Consequently, an average particle number removal rate of 60% can be achieved with the NPBI system in much less time than with the natural decay time.

Keywords: Air purification; Antibacterial; COVID-19; Indoor air; Needle point bipolar ionization.

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Conflict of interest statement

Declarations. Ethics approval: The authors declare that the manuscript is not submitted to more than one journal for simultaneous consideration. The manuscript is original and not have been published elsewhere in any form or language (partially or in full), unless the new work concerns an expansion of previous work. The manuscript is not split up into several parts to increase the quantity of submissions and submitted to various journals or to one journal over time. Results are presented clearly, honestly and without fabrication, falsification or inappropriate data manipulation. We adhere to discipline specific rules for acquiring, selecting, and processing data. Human Ethics and Consent to Participate declarations: not applicable. Consent to participate: I consent to participate publish my manuscript entitled “Needle Point Bipolar Ionization: Environmental Safety and Inactivation of Airborne Bacteria and Corona Virus” to the Environmental Science and Pollution Research (ESPR). Consent to publish: I consent to publish my manuscript entitled “Needle Point Bipolar Ionization: Environmental Safety and Inactivation of Airborne Bacteria and Corona Virus” to the Environmental Science and Pollution Research (ESPR). Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
A diagram of the experiment system
Fig. 2
Fig. 2
A) time-dependent LogTCID50 values of HCoV-229E with bipolar ionization treatment. B) Time-dependent % HCoV-229E reduction with bipolar ionization treatment
Fig. 3
Fig. 3
Mean colony counts of different bacterial species within 4 h for natural decay and bacterial recovery during the operation of NPBI device
Fig. 4
Fig. 4
Variation of NO2 and VOC pollutants in the office room before and during the operation of NPBI device. WM1: 2.68 m3/min; WM2: 3.26 m3/min; WM3: 3.88 m3/min
Fig. 5
Fig. 5
Variation of PM2.5 in the office room before and during the operation of NPBI device. WM1: 2.68 m3/min; WM2: 3.26 m3/min; WM3: 3.88 m3/min)
Fig. 6
Fig. 6
Particle number decrease percentage during the NPBI on and off in the office room
See this image and copyright information in PMC

References

    1. Abu-Hammad O, Alnazzawi A, Borzangy SS, Abu-Hammad A, Fayad M, Saadaledin S, Abu-Hammad S, Dar-Odeh N (2020) Factors influencing global variations in COVID-19 cases and fatalities; a review. In Healthcare 8(3):216. 10.3390/healthcare8030216 - PMC - PubMed
    1. Allen JG, Ibrahim AM (2021) Indoor air changes and potential implications for SARS-CoV-2 transmission. JAMA 325(20):2112–2113. 10.1001/jama.2021.5053 - PubMed
    1. ASHRE (2020) Changes in IAQ caused by corona discharge air cleaner. ASHRE J. https://www.ashrae.org/file%20library/technical%20resources/ashrae%20jou.... Accessed 26 Apr 2025
    1. Bari MA, Kindzierski WB, Wheeler AJ, Héroux MÈ, Wallace LA (2015) Source apportionment of indoor and outdoor volatile organic compounds at homes in Edmonton, Canada. Building Environ 90:114–124. 10.1016/j.buildenv.2015.03.023
    1. Baselga M, Alba JJ, Schuhmacher AJ (2023) Impact of needle-point bipolar ionization system in the reduction of bioaerosols in collective transport. Sci Total Environ 855:158965. 10.1016/j.scitotenv.2022.158965 - PMC - PubMed

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