Thread by @SMeerbeeck

Why it is important to equip day-care centres and #schools with mobile #air #filters: #Aerosol researchers launch position paper!

The scandal about the still insufficient equipment of day-care centres and #schools with #mobile #air #filters suggests that…
@realBertBlocken
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decision-makers in the ministries and administrations have still not understood how infections with the #coronavirus occur. The Deutsche Forschungsgemeinschaft (#DFG, German Research Foundation) is now countering this
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with an information paper that explains the correlations in simple terms.
It clearly states that it is ⚠️#negligent to rely solely on window ventilation in educational institutions.⚠️
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"The course of the COVID-19 pandemic so far has shown: #Aerosols contribute significantly to the incidence of infection - and blocking these can significantly reduce a resurgence in the number of infections," according to a recent press release from the #DFG @dfg_public
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dfg.de/service/presse…

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"The question of effective protective measures will become acute in autumn at the latest, because seasonal factors, new virus variants, declining immunity after vaccination or lack of willingness to vaccinate mean that there is still a risk of a 4th wave of infection in 🇩🇪."
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Still, only 70% of the citizens in 🇩🇪are informed about the danger of #aerosols - which is why the #DFG has now published an information paper on the subject. The focus is also on #schools and #daycare centres.
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"#Prevention of infection will remain significant in the long term, as the #pandemic cannot be overcome quickly, nor easily, and more infectious viral variants circulate," the paper says. "Current modelling predicts that lasting control of the pandemic cannot be achieved…
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with realistic #vaccination rates only, and measures for sustainable infection control will remain necessary in the long term. Thus, protective #measures against #aerosol dispersal not only reduce the risk of infection with SARS-CoV-2 via exhaled aerosol particles, but…
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also help reduce #infections with other #airborne pathogens (e.g. #influenza viruses)." This is no small matter: according to "Paediatricians on the Net", 16 #children up to the age of 15 died of the flu in 🇩🇪 in 2018 and 12 in 2019.
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kinderaerzte-im-netz.de/krankheiten/gr…

"According to the current state of research, #transmission takes place almost without exception #indoors" - like in #classrooms

The great risk of infection indoors is related to the fact that both 1️⃣direct and
2️⃣indirect infections take place here.
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1️⃣Direct infections are favoured when people talk to each other over a short distance for a long time without moving - like in #school.

2️⃣Indirect infections occur when …
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people stay in a room for a long time - such as in #schools and #daycare centres - and there is a high viral load in the room air due to a lack of #air exchange.

"In addition, it must be taken into account that in poorly ventilated indoor spaces, infection can occur…
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even without a direct encounter if an infectious person has previously stayed there for a longer period of time. Therefore, "#cluster infections" or "#superspreading events" may occur indoors during the COVID-19 pandemic" - including in #schools.
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"Heavy #breathing activities (e.g. #choir and #orchestra rehearsals, heavy #physical work, #gym sports) also increase the risk of 2️⃣indirect infection."

"The indirect risk of infection can be minimised indoors by people only staying there for a short time,…
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by keeping the concentration of infectious #aerosols as low as possible through strong #air #exchange or by wearing particle-filtering #masks. A strong #air exchange can be achieved by window #ventilation, permanently installed ventilation systems or mobile air #purifiers.
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However, practical #problems arise:
👉🏼"Rapid air exchange through window ventilation requires regular cross-ventilation (6 times/h, draft by opening windows on opposite sides of the room, if necessary also in neighbouring rooms)
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👉🏼or equally frequent shock ventilation (by fully opening all existing windows in the room).
👉🏼A fan in the window can further reduce the indirect risk of infection.
👉🏼Permanently installed #ventilation systems should be operated with 100% fresh air…
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(no recirculation) at maximum volume flow.
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Mobile #airpurifiers to reduce viral load if measures are
👉🏼technically impossible (no ventilation systems available, too few windows that can be opened),
👉🏼physically ineffective (no temperature difference between indoors and outdoors,
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insufficient wind in front of the windows)
👉🏼impractical (interruption of work processes),
👉🏼unreasonable (too cold, draughts, too loud outside noise)

Unlike fixed air handling units, high quality, high performance #mobile #air #purifiers can be installed at short notice."
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By combining the #measures, "comprehensive infection #protection is possible indoors" - also in #classrooms.
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Important: "Since window ventilation, ventilation systems and #mobile #air #purifiers only protect against 2️⃣indirect infection, but do not provide protection against 1️⃣direct infection, ⚠️they are NO substitute for #masks of any kind. ⚠️
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However, in combination with #measures that protect against 1️⃣direct infection, such as spacing, surgical masks, good mouth-nose coverings or transparent protective walls, comprehensive #indoor #infection #control is possible."
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Conclusion of the authors: "The best protection is always provided by a COMBINATION of measures to prevent 1️⃣direct infections, i.e.
👉🏼contact avoidance,
👉🏼distance rules,
👉🏼masks
👉🏼protective walls
and….
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measures to prevent 2️⃣indirect infections, i.e.
👉🏼ventilation,
👉🏼ventilation systems,
👉🏼efficient mobile room air cleaners
👉🏼suitable masks".
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According to the experts involved, only regulations that are as free of contradictions and uniform as possible guarantee a high level of safety with as few restrictions as possible in everyday life and quality of life.
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However, there is still a lack of consistent regulations: The federal programme for the promotion of mobile air filters in day-care centres and schools, for example, as is currently evident in the tender conditions (News4teachers reports),…
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only finances the equipment of #classrooms "with limited #ventilation possibilities". [..]not per se suitable for teaching or spending time with groups of #children - if only because of the rising #CO2 levels in the air we breathe, as the Federal Environment Agency states.
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news4teachers.de/2021/08/warum-…

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