Where are we with ventilation in closed anti Covid environments?
Studies, opinions and criticisms on what has been (or has not been) done in Italy for indoor ventilation as an anti Covid tool
Whatever people say, the anti Covid vaccines, according to various studies and data , are making a difference in the number of infections, hospitalizations and deaths. The less a population is immunized, the more cases increase, the possibility that variants will emerge as a result of mutations of the virus and, in some cases, that more restrictive measures, or even lockdowns, will be imposed.
But we are sure that we have tried all ways to decrease the pressure on hospitals and avoid running into restrictions that damage everyone, from the social life of children and young people, but also the older ones, to businesses forced to close or having to make sacrifices to the common good?
TWO STREETS NOT STILL BEATEN: TRACKING + FILTERS AND CONTROLLED MECHANICAL VENTILATION
Professor Luca Ricolfi, political scientist and sociologist as well as president of the Hume Foundation, wrote in Repubblica that the path taken by Italy and most of Europe, that is "vaccines + restrictions" is not the right one "to keep the 'epidemic".
The fact that summer gives us "the illusion of taming the virus" and then "vanishes with autumn", explains the sociologist, should make us reflect on the possibility that there are also alternatives "beyond perpetual vaccination ".
“In reality”, writes Ricolfi, “alternatives other than the vaccination + sacrifice dyad exist, and have been indicated several times, not only by scholars”.
Among these, the two most significant are electronic tracking – “abandoned after the failure of the Immuni app” – and “securing closed environments, starting with schools, offices, subways, with filters and controlled mechanical ventilation”.
WHAT (VA) GIMBE SAYS
The alternative routes proposed by Ricolfi are nothing new, yet they continue to not be adequately put into practice. It was December 5, 2020 when a report by the Gimbe Foundation, published on Start , stated that, according to a Cnr-Isac study, virus particles "abound in environments devoid of solar radiation" and are favored "by dry and cold conditions".
Gimbe therefore recommended "to maintain adequate humidification of the indoor air (in the range 40-60%), especially where there are temperatures below 20 ° C, the use of air purifiers, a adequate mechanical ventilation even in winter and the measurement of the concentration of carbon dioxide (CO2) in the air ".
Almost a year later, in October 2021 , the Foundation wrote in another report: "Despite the evidence showing that the transmission of Sars-Cov-2 occurs mainly by aerosols, too many resources continue to be invested in the disinfection procedures of surfaces and very few in the aeration and ventilation systems ".
WHAT WAS IN THE DISTRIBUTION DECREE
The Division Decree , which assigned 350 million euros to schools – reads the report – provided for the purchase of "tools for ventilation", but this intended use is not specified in Legislative Decree 73/2021 which only refers to minor maintenance interventions.
Consequently, aeration and ventilation are entrusted to keeping the windows open, the effectiveness of which depends on the sensitization of the school staff and on the continuous ventilation of the rooms during the activities, which cannot fail to be conditioned by the weather conditions.
THE STUDY OF THE CNR
According to a study conducted for the first time in Italy , by the Institutes of Atmospheric and Climate Sciences and Polar Sciences of the Cnr, Ca 'Foscari University of Venice and the Experimental Zooprophylactic Institute of Puglia and Basilicata, published in Environmental Science and Pollution Research , with mask, spacing and air exchange, in indoor public places the risk of transmission in the air of Sars-Cov-2 was lower than the minimum detectable.
The research, which took place between November and December 2020, during the maximum spread of the second wave of the pandemic in Italy, analyzed the concentration of viral particles in the air in different community environments operating even during the restrictions: the railway station Mestre and two supermarkets in the metropolitan area of Venice; the Cnr canteen of the research area of Bologna; a shopping center, a pharmacy, and a hairdressing salon in Lecce. The data collected therefore affected areas of the country with significantly different spread of the virus and atmospheric conditions.
THE RESULTS
"All the [aerosol, ed ] samples collected were negative and no differences were observed in opening hours, presence of people and closures of the environments", said Daniele Contini of the Institute of Atmospheric and Climate Sciences. of the Cnr-Isac of Lecce.
"This reinforces the importance of observing the rules on masks, spacing and controls in closed environments, increasing ventilation as much as possible", stressed Franco Belosi of Cnr-Isac.
"A greater risk could in fact occur in poorly ventilated indoor environments, where respiratory droplets can remain in suspension for longer times and deposit on surfaces, increasing the possibility of contamination by indirect contact (mediated by surfaces) compared to direct contact between individuals ”, added Andrea Gambaro, lecturer at the Ca 'Foscari University.
THE PROPOSALS
For a more precise definition of the risk, the CNR informs, it is therefore extremely important to answer the questions about the role of airborne transmission in specific indoor community environments, such as schools, supermarkets, restaurants, public transport.
For the engineer Giorgio Buonanno, we read in an article with Ricolfi in Repubblica , "the virus spreads almost exclusively by aerosols and not with droplets (droplets) or surfaces" and "the risk of inhaling a sufficient dose of viral load suspended in the air, on the other hand, is significant in closed environments without intervening on the environment ".
Despite this scientific evidence, according to the expert, the error of the authorities lies in the fact that they relied "only on the vaccine, without involving the engineers". Without their involvement, in fact, says Buonanno, in addition to possible continuing social tensions, it is "probable that the feared closures will occur with serious consequences on the health and economic level".
Reason why, he suggests, "an endless summer".
This is a machine translation from Italian language of a post published on Start Magazine at the URL https://www.startmag.it/sanita/a-che-punto-siamo-con-la-ventilazione-negli-ambienti-chiusi-anti-covid/ on Wed, 08 Dec 2021 07:15:54 +0000.