Assessment of Health Risks Associated With the Emission of Reactive Species During Routine Wound Treatment With a Medical Device Based on Cold Atmospheric Plasma

Abstract

Cold atmospheric plasma (CAP) devices are increasingly used in wound therapy due to their antimicrobial and tissue-stimulating effects. However, CAP treatment generates reactive oxygen and nitrogen species (RONS), some of which may escape the treatment site and affect indoor air quality. The objective of this study was to assess potential health risks associated with emissions of long-lived reactive species during routine CAP wound therapy. Emission rates for ozone and nitrogen oxides were experimentally quantified for a dielectric barrier discharge (DBD) CAP source operated on porcine ear tissue as a surrogate for human skin. These rates were inputted into a computational fluid dynamics (CFD) model to predict spatiotemporal ozone concentrations across six indoor scenarios, including single and triple inpatient rooms and a multiple outpatient setting, evaluated with and without air change rate (2 h⁻¹). Simulations covered an 8-h working day and incorporated CAP wound therapy schemes developed with healthcare professionals. Ozone was identified as the dominant long-lived species emitted during CAP operation. Measured ozone emission rates ranged from 0.14 to 1.15 μg s⁻¹, which is notably lower than previously reported rates for operation against metallic surfaces. Nitrogen oxide emissions were negligible, with maximum rates roughly two orders of magnitude lower than those of ozone. CFD simulations indicated that transient ozone concentrations increased locally by up to 7.2 μg m⁻³ at the medical staff position in unventilated scenarios. For 8-h exposures, the maximum CAP-induced relative increase was 3.2 μg m⁻³. Absolute 8-h average ozone concentrations, which include substantial background concentrations, are expected to range from 9.8 to 41.0 μg m⁻³, remaining far below the WHO guideline value of 100 μg m⁻³, even under worst-case conditions. We conclude that routine CAP wound therapy poses no significant health risk to patients or medical staff, as indoor ozone levels are governed predominantly by background concentrations rather than CAP operation.