Scientists recommend at least 40% humidity in public buildings to curb COVID-19 spread
New Delhi: In addition to measures like social distancing and wearing masks, an Indian-German team of scientists recommend controlling indoor humidity conditions to contain the spread of the novel coronavirus which causes COVID-19.
The researchers, including those from CSIR National Physical Laboratory in New Delhi, said in order to contain the pandemic, it is extremely important to implement standards for indoor air humidity in rooms with many people, such as hospitals, open-plan offices, or public transport.
In their review of studies, published in the journal Aerosol and Air Quality Research, the scientists specifically drew focus on relative humidity, which is a measure of water vapour in the air compared to the total saturation of vapour that can exist in the air at its current temperature.
According to the study, a relative humidity of 40 to 60 percent could reduce the spread of viruses and their absorption through the nasal mucous membrane.
The scientists said tiny drops of five micrometres in diameter, such as those produced when speaking, can float in the air for up to nine minutes.
"In aerosol research, it has long been known that air humidity plays a major role -- The more humid the air is, the more water adheres to the particles and so they can grow faster. So, we were curious -- what studies have already been conducted on this," explained Ajit Ahlawat, a co-author of the study from the Leibniz Institute for Tropospheric Research (TROPOS) in Germany.
According to the scientists, humidity affects the behaviour of microorganisms within the virus droplets, and the survival or inactivation of the virus on the surfaces.
They said it also influences the role of dry indoor air in the airborne transmission of viruses.
"If the relative humidity of indoor air is below 40 per cent, the particles emitted by infected people absorb less water, remain lighter, fly further through the room and are more likely to be inhaled by healthy people," Ahlawat explained.
"In addition, dry air also makes the mucous membranes in our noses dry and more permeable to viruses," he said.
The scientists believe the new findings are particularly important for the upcoming winter season in the northern hemisphere, when millions of people will be staying in heated rooms.
"Heating the fresh air also ensures that it dries. In cold and temperate climate zones, therefore, the indoor climate is usually very dry during the heating season. This could encourage the spread of coronaviruses," said study co-author Alfred Wiedensohler of TROPOS.
At a higher humidity, the scientists said droplets grow faster, fall to the ground earlier, and can be inhaled less by healthy people.
"A humidity level of at least 40 per cent in public buildings and local transport would therefore not only reduce the effects of COVID-19, but also of other viral diseases such as seasonal flu. Authorities should include the humidity factor in future indoor guidelines," added study co-author Sumit Kumar Mishra of CSIR - National Physical Laboratory in New Delhi.
For countries in cool climates, the scientists recommend a minimum indoor humidity.
They said countries in tropical and hot climates, on the other hand, should take care that indoor rooms are not extremely undercooled by air conditioning systems.
When air is extremely cooled, it dries out the air and the particles in it, making people inside the room feel comfortable, but the dry particles will remain in the air for longer duration, the researchers warned.
They added that the measures already known, such as social distancing, having as few people per room as possible, and wearing masks should also be practised to lower the risk of infection.
Let the Truth be known. If you read VB and like VB, please be a VB Supporter and Help us deliver the Truth to one and all.
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.
