Holding breath may increase the risk of contracting the SARS-CoV-2 virus, according to a study carried out by researchers at the Indian Institute of Technology, Madras (IITM).
The researchers noted in their study, published in the journal Physics of Fluids, that the process of virus-laden droplets being transported into the deep lungs increases with a fall in breathing frequency.
For the study, the research team modelled the breathing frequency in a laboratory and found that low breathing frequency increases the time of residence of the virus. Therefore, it increases the chances of deposition and consequently the risk of infection.
Lung structure
Also, the multiscale lung structure has a significant effect on a person’s susceptibility to Covid-19.
Lead author Prof Mahesh Panchagnula, Department of Applied Mechanics, IIT Madras, explained: “Covid-19 has opened a gap in our understanding of deep pulmonological systemic diseases. Our study unravels the mystery behind how particles are transported and deposited in the deep lung. The study demonstrates the physical process by which aerosol particles are transported into the deep generations of the lung.”
Panchagnula and the team worked to gain a deeper understanding of how the rate of flow of droplets laden with virus determines the deposition of the virus in the lungs.
Virus deposition
In their research, the team reported that holding breath and having a low breathing rate can increase the chances of virus deposition in the lungs.
The IIT Madras research team imitated the droplet dynamics in the lung by studying the movement of droplets in the small capillaries which were of a diameter similar to bronchioles.
They took water mixed with fluorescent particles and generated aerosols from this liquid using a nebulizer. These fluorescent aerosols were used to track the movement and deposition of particles in the capillaries.
The researchers studied the movement of the fluorescent aerosol particles in capillaries of sizes ranging from 0.3 to 2 millimeters which cover the range of bronchiole diameters.
Their findings suggested that the deposition is inversely proportional to the aspect ratio of capillaries, which suggest that the droplets are likely to deposit in longer bronchioles.