UV light dosage distribution over irregular respirator surfaces. Methods and implications for safety

Autor: Julio Cortiñas, Maria Teresa Flores-Arias, Justo Arines, Ramon Vilanova, C. Bao-Varela, Aurora Baluja
Rok vydání: 2020
Předmět:
2019-20 coronavirus outbreak
business.product_category
Materials science
Coronavirus disease 2019 (COVID-19)
Ultraviolet Rays
Electromagnetic spectrum
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
Pneumonia
Viral
Irradiance
Grating
010501 environmental sciences
Radiation Dosage
01 natural sciences
Betacoronavirus
03 medical and health sciences
Optics
0302 clinical medicine
Equipment Reuse
Humans
Dosimetry
Respiratory Protective Devices
Respirator
Pandemics
Personal protective equipment
Decontamination
0105 earth and related environmental sciences
Spectrometer
SARS-CoV-2
business.industry
Public Health
Environmental and Occupational Health
COVID-19
030210 environmental & occupational health
Wavelength
Angle of incidence (optics)
Coronavirus Infections
business
Biomedical engineering
Zdroj: Journal of Occupational and Environmental Hygiene. 17:390-397
ISSN: 1545-9632
1545-9624
DOI: 10.1080/15459624.2020.1786576
Popis: Background and ObjectivesThe SARS-CoV-2 pandemic has led to a global decrease in personal protective equipment (PPE), especially filtering facepiece respirators (FFRs). Ultraviolet-C wavelength is a promising way of decontamination, however adequate dosimetry is needed to ensure balance between over and underexposed areas and provide reliable results. Our study demonstrates that UVGI light irradiance varies significantly on different respirator angles and propose a method to decontaminate several masks at once ensuring appropriate dosage in shaded zones.MethodsAn UVGI irradiator was built with internal dimensions of 69.5 × 55 × 33 cm with three 15W UV lamps. Inside, a grating of 58 × 41 × 15 cm was placed to hold the masks. Two different flat fold respirator models were used to assess irradiance, four of model Aura 9322 3M of dimensions 17 × 9 × 4cm (tri-fold), and two of model SAFE 231FFP3NR (bi-fold) with dimensions 17 × 6 × 5 cm. A spectrometer STN-SilverNova was employed to verify wavelength spectrum and surface irradiance. A simulation was performed to find the irradiance pattern inside the box and the six masks placed inside. These simulations were carried out using the software DIALUX EVO 8.2.ResultsThe data obtained reveal that the irradiance received inside the manufactured UVGI-irradiator depends not only on the distance between the lamps plane and the base of the respirators but also on the orientation and shape of the masks. This point becomes relevant in order to assure that all the respirators inside the chamber receive the correct dosage.ConclusionIrradiance over FFR surfaces depend on several factors such as distance and angle of incidence of the light source. Careful irradiance measurement and simulation can ensure reliable dosage in the whole mask surface, balancing overexposure. Closed box systems might provide a more reliable, reproducible UVGI dosage than open settings.
Databáze: OpenAIRE
Externí odkaz: