Publications

Engineering infection controls include a wide range of interventions used indoors to reduce occupants’ exposure to respiratory pathogens.

Germicidal ultraviolet light (GUV) is gaining attention for air disinfection, particularly following the COVID-19 pandemic. GUV air cleaning devices use 222 or 254 nm light to remove airborne and surface pathogens from indoor environments, although their impact on indoor chemistry has received limited attention.

COVID-19 highlighted the challenges of public acceptance of public health measures, including mask-wearing and vaccination. which has spurred interest in engineered approaches to reduce infections. Germicidal Ultraviolet (GUV) Energy has been used for decades in hospital rooms to limit TB transmission, but it is expensive to install in the upper part of rooms where it may be used safely

In this case study, we describe a well-resourced private school in New York City that implemented COVID-19mitigation measures based on public health expert guidance and the lessons learned from this process

Improving indoor air quality (IAQ) will diminish routine exposure to airborne diseases,^1,2 limit outbreaks or epidemics,³ and lower risks of noninfectious respiratory conditions like asthma that affect the health of millions each year.⁴ Improving IAQ is also cost-effective. Proper ventilation and filtration in crowded public indoor settings can significantly reduce the costs of illness at a benefit-cost ratio ranging from 3:1 to 100:1,⁵ exceeding similar ratios for most other public health interventions.⁶

The Johns Hopkins Center for Health Security hosted a meeting, “National Strategy for Improving Indoor Air Quality,” in Washington, DC, on September 8, 2022. The meeting featured a keynote speaker and four expert panels focused on the importance of indoor air quality (IAQ), challenges to providing healthy indoor air across the United States, international perspectives and strategies for healthy air improvements, and catalyzing needed science and technology innovation in the IAQ field. Dr. Ashish Jha, White House COVID-19 Response Coordinator, opened the meeting by reiterating the importance of IAQ to the Biden-Harris Administration. 

Ventilation is of primary concern for maintaining healthy indoor air quality and reducing the spread of airborne infectious disease, including COVID-19. In addition to building-level guidelines, increased attention is being placed on room-level ventilation. However, for many universities and schools, ventilation data on a room-by-room basis are not available for classrooms and other key spaces. We present an overview of approaches for measuring ventilation along with their advantages and disadvantages. We also present data from recent case studies for a variety of institutions across the United States, with various building ages, types, locations, and climates, highlighting their commonalities and differences, and examples of the use of this data to support decision making.

Many kindergarten through 12th grade (K-12) schools in the United States do not have good ventilation. This is a longstanding problem with demonstrably negative effects on student learning. We can and should act to fix this to ensure good indoor air quality for all students, educators, and school staff. During the COVID-19 pandemic, it is even more important that ventilation problems in K-12 schools be addressed now. Along with other mitigation measures, improvements in ventilation in K-12 schools can decrease the risk of SARS-CoV-2 spread.

Coordination of efforts to assess the challenges and pain points felt by industries from around the globe working to reduce COVID-19 transmission in the indoor environment as well as innovative solutions applied to meet these challenges is mandatory. Indoor infectious viral disease transmission (such as coronavirus, norovirus, influenza) is a complex problem that needs better integration of knowledge. Critical to providing a reduction in transmission is to map the four core technical areas of environmental microbiology, transmission science, building science, and social science. To that end a three-stage science and innovation Summit was held to gather information on current standards, policies and procedures applied to reduce transmission in built spaces, as well as the technical challenges, science needs, and research priorities. The Summit elucidated steps than can be taken to reduce transmission of SARS-CoV-2 indoors and calls for significant investments in research to develop knowledge of viral pathogen persistence and transport in the built environment, risk assessment and mitigation strategy considerations including such as processes and procedures to reduce the risk of exposure and infection including building systems operations, biosurveillance capacity, communication, leadership, and stakeholder engagement for optimal response. The findings reflect the effective application of existing knowledge and standards, emerging science, and lessons-learned from current efforts to confront SARS-CoV-2.