WO3/Pt photocatalyst supported by ceramic filter for indoor air purification under visible light irradiation DOI Creative Commons
Sudipto Pal,

Amruth Kaitheri,

Sanosh Kunjalukkal Padmanabhan

и другие.

Environmental Science Advances, Год журнала: 2024, Номер 3(12), С. 1775 - 1787

Опубликована: Янв. 1, 2024

Household air pollution exposure can lead to various chronic health issues, photocatalytic purification could improve the indoor quality.

Язык: Английский

Ozone Generation from a Germicidal Ultraviolet Lamp with Peak Emission at 222 nm DOI
Michael F. Link, Andrew Shore, Behrang H. Hamadani

и другие.

Environmental Science & Technology Letters, Год журнала: 2023, Номер 10(8), С. 675 - 679

Опубликована: Июль 24, 2023

Recent interest in commercial devices containing germicidal ultraviolet lamps with a peak emission wavelength at 222 nm (GUV222) has focused on mitigating virus transmission indoors while posing minimum risk to human tissue. However, light can produce ozone (O3) air. O3 is an undesirable component of indoor air because health impacts from acute chronic exposure and its ability degrade quality through oxidation chemistry. In seven 4 h experiments, we measured the production single filtered GUV222 lamp 31.5 m3 stainless steel chamber. Using model, determined generation rate 19.4 ppbv h–1 ± 0.3 (equivalent 1.22 mg 0.02 h–1). We estimated fluence using two methods: (1) chemical actinometry tetrachloroethylene (actinometry) (2) geometric projection irradiance field radial angular distribution measurements (irradiance). rates 2.2 μW cm–2 3.2 (irradiance), predicted our chamber within 20% average mixing ratio. Future studies should evaluate technologies.

Язык: Английский

Процитировано

30

Far-UVC disinfection of airborne and surface virus in indoor environments: Laboratory experiments and numerical simulations DOI

Kangqi Guo,

Yue Pan,

Hoi Fung Ronaldo Chan

и другие.

Building and Environment, Год журнала: 2023, Номер 245, С. 110900 - 110900

Опубликована: Окт. 7, 2023

Язык: Английский

Процитировано

18

Effects of 222 nm Germicidal Ultraviolet Light on Aerosol and VOC Formation from Limonene DOI Creative Commons
Olivia J. Jenks, Zhe Peng, Melinda K. Schueneman

и другие.

ACS ES&T Air, Год журнала: 2024, Номер 1(7), С. 725 - 733

Опубликована: Май 4, 2024

Since the 1930s, germicidal ultraviolet (GUV) irradiation has been used indoors to prevent transmission of airborne diseases, such as tuberculosis and measles. Recently, it received renewed attention due COVID-19 pandemic. While GUV radiation shown be effective in inactivating bacteria viruses, few studies on impact indoor air quality have published. In this work, we evaluate effects GUV222 (GUV at 222 nm) chemistry a common volatile organic compound (VOC), limonene. We found that production O3 by lamps caused formation particulate matter (PM) oxygenated compounds (VOCs). also proceeds through ozonolysis limonene well reaction with secondary OH, presence light led observable but small perturbations chemistry. Understanding is important evaluating safety these devices.

Язык: Английский

Процитировано

7

Effectiveness, Safety, and Challenges of UVC Irradiation in Indoor Environments: A Decade of Review and Prospects DOI

Chaofan Lin,

Junzhou He,

Zhijian Liu

и другие.

Building and Environment, Год журнала: 2025, Номер unknown, С. 112868 - 112868

Опубликована: Март 1, 2025

Язык: Английский

Процитировано

1

Reducing Transmission of Airborne Respiratory Pathogens: A New Beginning as the COVID-19 Emergency Ends DOI Creative Commons
Linsey C. Marr, Jonathan M. Samet

Environmental Health Perspectives, Год журнала: 2024, Номер 132(5)

Опубликована: Май 1, 2024

In response to the COVID-19 pandemic, new evidence-based strategies have emerged for reducing transmission of respiratory infections through management indoor air.

Язык: Английский

Процитировано

6

Ozone generation and chemistry from 222 nm germicidal ultraviolet light in a fragrant restroom DOI
Michael F. Link,

Rileigh L. Robertson,

Andrew Shore

и другие.

Environmental Science Processes & Impacts, Год журнала: 2024, Номер 26(6), С. 1090 - 1106

Опубликована: Янв. 1, 2024

Devices using 222 nm germicidal ultraviolet light (GUV222) have been marketed to reduce virus transmission indoors. However, GUV222 generates ozone which can react with gases and surfaces create undesirable air byproducts.

Язык: Английский

Процитировано

6

Pentagon Found Daily, Metagenomic Detection of Novel Bioaerosol Threats to Be Cost-Prohibitive: Can Virtualization and AI Make It Cost-Effective? DOI Creative Commons
Devabhaktuni Srikrishna

Health Security, Год журнала: 2024, Номер 22(2), С. 108 - 129

Опубликована: Апрель 1, 2024

In 2022, the Pentagon Force Protection Agency found threat agnostic detection of novel bioaerosol threats to be "not feasible for daily operations" due cost reagents used metagenomics, sequencing instruments, and labor subject matter experts analyze bioinformatics. Similar operational difficulties might extend many 280,000 buildings (totaling 2.3 billion square feet) at 5,000 secure US Department Defense military sites, 250 Navy ships, as well civilian buildings. These economic barriers can still addressed in a manner by dynamically pooling samples from dry filter units, called spike-triggered virtualization, whereby depth are automatically modulated based on biothreats output. By running high average factor, annual per unit reduced 10 100 times depending chosen trigger thresholds. Artificial intelligence further enhance sensitivity virtualization. The risk infection during 12- 24-hour window between incident its remains, but some cases it 80% or more with high-speed indoor air cleaning exceeding 12 changes hour, which is similar rate passenger airplanes flight. That level hour higher likely cost-prohibitive using central heating ventilation conditioning systems, achieved economically portable filtration rooms typical ceiling heights (less than approximately $0.50 $1 foot do-it-yourself units $2 $5 high-efficiency particulate filters.

Язык: Английский

Процитировано

4

Quantification of Byproduct Formation from Portable Air Cleaners Using a Proposed Standard Test Method DOI
Michael F. Link,

Rileigh Robertson,

Megan S. Claflin

и другие.

Environmental Science & Technology, Год журнала: 2024, Номер 58(18), С. 7916 - 7923

Опубликована: Апрель 29, 2024

In response to the COVID-19 pandemic, air cleaning technologies were promoted as useful tools for disinfecting public spaces and combating airborne pathogen transmission. However, no standard method exists assess potentially harmful byproduct formation from cleaners. Through a consensus development process, draft test portable cleaner performance was developed, suite of cleaners employing seven different tested. The quantifies not only removal efficiency challenge chemical ultrafine particulate matter but also formation. Clean delivery rates (CADRs) are used quantify particle efficiencies, an emission rate framework is formaldehyde, ozone, other volatile organic compounds. We find that tested photocatalytic oxidation germicidal ultraviolet light (GUV) produced highest levels aldehyde byproducts having 202 243 μg h

Язык: Английский

Процитировано

4

Formation and Transport of Secondary Contaminants Associated with Germicidal Ultraviolet Light Systems in an Occupied Classroom DOI
Seongjun Park, Youngbo Won, Donghyun Rim

и другие.

Environmental Science & Technology, Год журнала: 2024, Номер 58(27), С. 12051 - 12061

Опубликована: Июнь 26, 2024

Germicidal ultraviolet light (GUV) systems are designed to control airborne pathogen transmission in buildings. However, it is important acknowledge that certain conditions and system configurations may lead GUV produce air contaminants including oxidants secondary organic aerosols (SOA). In this study, we modeled the formation dispersion of generated by operation employing C 254 222 nm. Using a three-dimensional computational fluid dynamics model, examined breathing zone concentrations chemical species an occupied classroom. Our findings indicate operating leads approximate increase 10 ppb O3 concentration 5.2 μg·m–3 SOA compared condition without operation, while increases about 1.2 μg·m–3, with minimal impact on concentration. Furthermore, increasing UV fluence rate from 1 5 μW·cm–2 results up 80% concentrations. For 254, elevating 30 50 or doubling radiating volume 50% Note indoor airflow patterns, particularly buoyancy-driven (or displacement ventilation), 15–45% lower well-mixed airflow. The also reveal when ventilation below 2 h–1, has smaller human exposure than 222. generate more at high levels (>15 ppb). These suggest design should consider room conditions.

Язык: Английский

Процитировано

4

Influence of Germicidal UV (222 nm) Lamps on Ozone, Ultrafine Particles, and Volatile Organic Compounds in Indoor Office Spaces DOI Creative Commons
Sara Bjerre Sørensen, Frederik R. Dalby, Søren Bøye Olsen

и другие.

Environmental Science & Technology, Год журнала: 2024, Номер 58(45), С. 20073 - 20080

Опубликована: Окт. 28, 2024

Germicidal ultraviolet lamps with a peak emission at 222 nm (GUV222) are gaining prominence as safe and effective solution to reduce disease transmission in occupied indoor environments. While previous studies have reported O

Язык: Английский

Процитировано

4