Indian scientists find N95 masks to be most effective at stopping COVID-19 spread
New Delhi: N95 masks may be the most effective at reducing the spread of the novel coronavirus, according to a study by researchers, including those from the Indian Space Research Organisation (ISRO), which suggests that any mask is better than no mask at preventing COVID-19.
The researchers noted that airborne transmission by respiratory aerosol droplets produced during coughing and sneezing is the dominant mode of spreading for infectious diseases such as COVID-19.
Padmanabha Prasanna Simha, from ISRO, and Prasanna Simha Mohan Rao, from the Sri Jayadeva Institute of Cardiovascular Sciences and Research in Karnataka, experimentally visualised the flow fields of coughs under various common mouth covering scenarios.
The, study published in the journal Physics of Fluids, found N95 masks to be the most effective at reducing the horizontal spread of a cough.
The N95 masks reduced a cough's initial velocity by up to a factor of 10, and limit its spread to between 0.1 and 0.25 meters, the researchers said.
An uncovered cough, in contrast, can travel up to three metres, but even a simple disposable mask can bring this all the way down to 0.5 metres, they said.
"If a person can reduce the extent of how much they contaminate the environment by mitigating the spread, it's a far better situation for other healthy individuals who may enter places that have such contaminated areas," Simha said.
Rao and Simha noted that density and temperature are intricately related, and coughs tend to be warmer than their surrounding area.
They utilised a technique called schlieren imaging, which visualises changes in density, to capture pictures of voluntary coughs from five test subjects.
By tracking the motion of a cough over successive images, the team estimated velocity and spread of the expelled droplets. N95 masks have the best effectiveness and completely contain the horizontal spread to between 0.1 and 0.25 metres, researchers said.
A disposable surgical mask greatly reduces this distance to between 0.5 and 1.5 metres, they said.
"Even if a mask does not filter out all the particles, if we can prevent clouds of such particles from traveling very far, it's better than not doing anything," said Simha.
"In situations where sophisticated masks are not available, any mask is better than no mask at all for the general public in slowing the spread of infection," said Simha.
The researchers also contradict the generally accepted notion that using an elbow to cover up a cough is a good alternative. The found that unless covered by a sleeve, a bare arm cannot form the proper seal against the nose necessary to obstruct airflow.
The researchers added that a cough is able to leak through any openings and propagate in many directions.
Simha and Rao hope their findings will put to rest the argument that regular cloth masks are ineffective, but they emphasise that masks must continue to be used in conjunction with social distancing.
"Adequate distancing is something that must not be ignored, since masks are not foolproof," Simha added.
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89 killed as storm, rain batter UP; relief work underway
Lucknow (PTI): At least 89 people were killed after a strong storm and heavy rain pounded several districts of Uttar Pradesh, uprooting trees and electric poles and damaging houses, according to the Relief Commissioner's office.
Chief Minister Yogi Adityanath took cognisance of the loss of lives and damage caused by the unseasonal rain, thunderstorms and lightning on Wednesday and directed officials to ensure relief reaches the affected families within 24 hours.
In a post on X on Thursday, the Relief Commissioner's office said, "Due to bad weather on May 13, including storms, rain, hailstorm and lightning, reports of 89 deaths, 53 injured persons, 114 livestock losses and damage to 87 houses have been received in the state, which has been taken cognisance of by the Hon'ble Chief Minister."
It said the chief minister has directed all divisional commissioners and district magistrates to verify the incidents "with full sensitivity" and ensure financial assistance is distributed to affected families within 24 hours while establishing direct communication with them and extending other necessary help.
The Relief Commissioner's office said it is continuously monitoring the situation through direct coordination with district officials and necessary funds are being made available to districts.
According to a list issued by the Prayagraj district administration, seven deaths were reported in the Handia area, four in Phulpur, three in Soraon, two in Meja and one in Sadar due to the storm and rain.
In Bhadohi, district administration sources said at least 16 people died in storm-related incidents.
Additional District Magistrate Kunwar Virendra Kumar Maurya said trees and electric poles were uprooted in several areas while many houses were damaged in the storm.
Fatehpur Additional District Magistrate Avinash Tripathi said nine people were killed and 16 injured in storm-related incidents in the district.
"Eight people, including five women, died in Khaga tehsil, while a woman died after a wall of a house collapsed in Sadar tehsil," he said.
In Pratapgarh, four people died in separate incidents of wall and cemented shed collapses and lightning strikes amid strong winds and rain, officials said.
Superintendent of Police Deepak Bhukar said Bhim Yadav (25) died after he was trapped under the debris of a cemented shed that collapsed in Ojha Ka Purwa village in the Lalganj Kotwali area.
He said Bhushan Pandey (56) died after a wall collapsed in Sari Swami village under the Baghrai police station area.
Bhukar said Shanti Devi (46) of Narangpur village and Lal Bahadur (44) of Chhatrapur Shivala Raghna village also died in storm-related incidents.
In Kanpur Dehat district, two persons died in rain-related incidents, the officials said.
Police sources said a 19-year-old woman, Ruchi, died after being struck by lightning in Bhauthari village under the Rasulabad area while standing under a neem tree with goats during heavy rain. Several goats also died in the incident.
A 60-year-old man standing nearby was injured, they added.
Additional District Magistrate (Finance and Revenue) Dushyant Kumar said reports regarding human and livestock losses have been sought from local officials and financial assistance will be provided as per government rules.
In Deoria, Komal Yadav (62), a resident of Bhimpur Gaura village, died after being struck by lightning, district administration sources said. Two others were injured in the incident.
In another incident, Ramnath Prasad (65), a resident of Neruari village, died in a lightning strike.
In Sonbhadra district, Madhav Singh (38) died after being trapped under a tree uprooted during the rain and the storm.
Adityanath directed the district magistrates and officials of various departments to visit the affected areas and provide all possible assistance to the victims and their families.
He also instructed the officials to remain alert and ordered the revenue and agriculture departments, along with insurance companies, to conduct a survey of the damage and submit a report to the government.
