Woman wearing protective mask goes through a temperature check before going to the office. … [+]
Three new scientific studies published this month show that the COVID-19 virus can spread in more ways than we once knew. Research from different parts of the world considered three separate factors in each study: low humidity, public toilets, and dust in the air. The implications of all three of these studies? Mask up!
Low humidity
A study just published in Border and emerging diseases confirms a previous study conducted in Greater Sydney, Australia in the early stages of the pandemic that reported a link between low humidity and the spread of the COVID-19 community. The new research led by Dr Michael Ward at the Sydney School of Veterinary Science adds to the growing body of evidence that low humidity is a major factor in the spread of the coronavirus. The scientists estimate that for a 1% decrease in relative humidity, COVID-19 cases increase by 7 to 8%. The same switch was not found in other weather patterns such as precipitation, temperature or wind.
According to Ward, dry air favors the spread of the virus: “” When the humidity is lower, the air is drier and it makes the aerosols smaller, “he said, adding that aerosols are smaller than droplets. cough, the smaller infectious aerosols can stay in the air longer. That increases the exposure to other people. When the air is humid and the aerosols are larger and heavier, they fall and reach surfaces more quickly. ”These findings add to a growing body of research that recommends wearing a mask.
Public toilets
A second study conducted by Chinese researchers from Yangzhou University reported that playing in a public toilet as a urinary cloud can release virus-laden aerosols that can be inhaled, posing a serious public health challenge. The scientists simulated and tracked movements with virus-laden particles while flushing toilets and urinals. They discovered that play involved an interaction between gas and liquid, which resulted in a large dispersal of aerosol particles.
The disturbing results showed that the trajectory of the particles extinct out of coil showed that more than 57% of the particles left the urinal. The researchers further pointed out that when men use urinals in a public restroom, these small particles can reach their thigh within 5.5 seconds compared to the toilet flush, which takes 35 seconds to reach slightly higher. “From our work it can be deduced that flushing of urnial indeed promotes the spread of bacteria and viruses,” said Xiang-Dong Liu, one of the study’s authors. “Wearing a mask should be mandatory in public restrooms during the pandemic, and anti-diffusion enhancements are urgently needed to prevent the spread of COVID-19.”
Airborne dust
A third study from the University of California, Davis and the Icahn School of Medicine at Mt. Sinai reported that airborne viruses can spread to dust, fibers, and other microscopic particles. Until now, scientists assumed that the transmission of air occurred mainly due to respiratory drops through coughing, sneezing or talking.
The scientists investigated whether spicy, non-respiratory particles could carry a flu between guinea pigs. Using an automatic particle sensor to count the particles of air, they found that non-infected guinea pigs produce spikes of up to 1,000 particles per second as they move around the cage. Particles emitted by the animals’ breathing were at a constant but lower rate. Immune guinea pigs with flu virus painted on their fur could transmit the virus through the air to other, susceptible guinea pigs, indicating that the virus did not have to come directly from the respiratory tract to be infectious.
Next, the researchers tested whether microscopic fibers of a living thing could carry infected viruses. They treated paper facial tissues with influenza virus, allowed them to dry out and then crawled in front of the automated particle sizer. Crumplings of the tissues released up to 900 particles per second in a large range that could be inhaled. They could also infect cells from these particles released from the virus-infected paper tissues. According to the researchers, the surprising findings that dust can spread viruses have obvious implications for coronavirus transmission and use of masks for protection. Plus, they said, it opens up a whole new field of research on how outbreaks are interpreted.
References
Ji-Xiang Wang, Yun-Yun Li, Xiang-Dong Liu, Xiang Cao. (2020). Virus transmission from urinals. Physics of liquids, 32 (8): 081703 DOI: 10.1063 / 5.0021450
Sima Asadi, Nassima Gaaloul ben Hnia, Ramya S. Barre, Anthony S. Wexler, William D. Ristenpart, Nicole M. Bouvier. (2020). Influenza A virus is transmitted through aerosolized fomites. Nature communication, 11 (1) DOI: 10.1038 / s41467-020-17888-w
Ward, MP, et al., (2020). Humidity is a consistent climatic factor contributing to SARS-CoV-2 transmission. Border and emerging diseases, DOI.org/10.1111/tbed.13766
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