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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MP HC sets up judicial commission to probe water contamination in Indore
Indore (PTI): The Indore bench of Madhya Pradesh High Court on Tuesday set up a commission of inquiry comprising a former HC judge to probe the issue of water contamination in city's Bhagirathpura, saying the matter requires probe by an independent, credible authority and "urgent judicial scrutiny".
It also directed the commission to submit an interim report after four weeks from the date of commencement of proceedings.
A division bench of Justices Vijay Kumar Shukla and Alok Awasthi constituted the commission while hearing several public interest litigations (PILs) filed simultaneously regarding the deaths of several people in Bhagirathpura due to the consumption of contaminated water.
The HC reserved the order after hearing all the parties during the day, and released it late at night.
The state government on Tuesday told the HC that the deaths of 16 people in Indore's Bhagirathpura area was possibly linked to a month-long outbreak of vomiting and diarrhoea caused by contaminated drinking water.
The government presented an audit report of 23 deaths from the current gastroenteritis epidemic in Bhagirathpura before the bench, suggesting that 16 of these fatalities may have been linked to the outbreak of vomiting and diarrhoea caused by contaminated drinking water.
The report, prepared by a committee of five experts from the city's Government Mahatma Gandhi Memorial Medical College, stated that the deaths of four people in Bhagirathpura were unrelated to the outbreak, while no conclusion could be reached regarding the cause of death of three other people in the area.
During the hearing, the high court sought to know from the state government the scientific basis behind its report.
The division bench also expressed surprise at the state government's use of the term "verbal autopsy" in relation to the report, sarcastically stating that it had heard the term for the first time.
The HC expressed concern over the Bhagirathpura case, stating that the situation was "alarming," and noted that cases of people falling ill due to contaminated drinking water have also been reported in Mhow, near Indore.
In its order, the HC said the serious issue concerning contamination of the drinking water supply in Bhagirathpura area allegedly resulted in widespread health hazards to residents, including children and elderly persons.
According to the petitioners and media reports, death toll is about 30 till today, but the report depicts only 16 without any basis or record, it said.
It is averred that sewage mixing, leakage in the pipeline, and failure of civic authorities to maintain potable water standards have led to the outbreak of water-borne diseases. Photographs, medical reports, and complaints submitted to the authorities prima facie indicate a matter requiring urgent judicial scrutiny, the HC said.
"Considering the gravity of the allegation and affecting the right to life under Article 21 of the Constitution of India and the need for an independent fact-finding exercise, the Court is of the opinion that the matter requires investigation by an independent, credible authority," it said.
"Accordingly, we appoint Justice Sushil Kumar Gupta, former judge of the Madhya Pradesh High Court, a one-man commission of inquiry into the issues relating to water contamination in Bhagirathpura, Indore, and its impact on other areas of the city," the HC added.
As per the order, the commission shall inquire into and submit a report on the cause of contamination -- whether the drinking water supplied to Bhagirathpura was contaminated; and the source and nature of contamination (sewage ingress, industrial discharge, pipeline damage etc).
The panel will also probe the number of actual deaths of affected residents on account of contaminated water; find out the nature of disease reported and adequacy of medical response and preventive measures; suggest immediate steps required to ensure safe drinking water as well as long-term infrastructural and monitoring reforms.
It will also identify and fix responsibility upon the officers and officials found prima facie responsible for the Bhagirathpura water contamination incident, and suggest guidelines for compensation to affected residents, particularly vulnerable sections.
The commission shall have powers of a civil court for the purpose of summoning officials and witnesses; calling up records from the government department, hospitals, laboratories and civic bodies; ordering water quality testing through accredited laboratories; conducting spot inspections.
All state authorities involving district administration, Indore Municipal Corporation, public health engineering department and Madhya Pradesh Pollution Control Board shall extend full co-operation and provide records as sought by the commission, it said.
The state government shall provide office space, staff, and logistical support to the commission, it said.
During the hearing in the day, the state government also presented a status report to the court in this matter.
According to reports, a total of 454 patients were admitted to local hospitals during the vomiting and diarrhea outbreak, of whom 441 have been discharged after treatment, and 11 are currently hospitalised.
According to officials, due to a leak in the municipal drinking water pipeline in Bhagirathpura, sewage from a toilet was also mixed in the water.
