Infection risk

Particle concentration and indoor air quality in naturally ventilated patient rooms-A field study in a hospital building in Bucharest, Romania

Submitted by on Mon, 01/13/2025 - 16:12

In response to the COVID-19 pandemic, there has been a significant emphasis on improving indoor air quality (IAQ), particularly within hospital buildings. Despite developments in integrated central advanced mechanical ventilation and filtration technologies in new hospital buildings, challenges persist in installing them in existing and old hospital buildings relying on traditional natural ventilation.

Experimental evaluation of the bidirectional filtration efficiency of respirators and face masks against airborne particles during cyclic breathing

Submitted by on Mon, 01/13/2025 - 15:47

In this work we investigate the bidirectional filtration efficiencies of respirators, such as FFP2 masks and medical masks, under cyclic breathing and different fits. We developed a test bench, which consists of a test chamber with an artificial head, and which is connected to a specially developed artificial breathing function. The exhalation filtration performance of masks can be evaluated by exhaling particle-laden air into the test chamber. Similarly, the inhalation filtration performance can be evaluated by inhalation of particle-laden air from the test chamber.

Can the Wells-Riley model universally assess airborne pathogen infection risk?

Submitted by on Thu, 03/07/2024 - 14:34

Some airborne pathogens can infect susceptible people over long distances in buildings when they are transported in small respiratory particles suspended in the air. The pathogen concentration in air can be decreased using engineering controls, such as ventilation, filtration, or inactivation. To determine their effect, it is common to use the Wells-Riley model to estimate the probability that a susceptible person is infected and is a function of the dose of infectious pathogen received and a Poisson distribution.

Infection risk-based ventilation design method

Submitted by on Thu, 03/02/2023 - 11:47

There is large amount of research on COVID-19 infections including the spread and removal mechanisms of the virus in indoor spaces. Ventilation, air cleaning and air disinfection are the main engineering measures to control the virus spread in buildings. Wells Riley model allows to calculate the infection risk probability for any airborne virus aerosol-based transmission, but this calculation is overcomplicated in the ventilation design because of large amount of input data needed that is not easy to understand to ventilation designers.