A teacher opens the windows in a classroom at IES Rosalia de Castro in the center of Santiago OSCAR CORRAL
To the Presidency of the Government of Spain, Autonomous Governments and other public positions with responsibilities in health matters:
One year of this situation has already been completed of emergency, of terrible consequences. Its solution will still require great efforts and the involvement of all. Therefore, first of all and as scientists and experts in various disciplines, we want to offer our disinterested collaboration in any task that may contribute to achieving this solution as a common goal.
In this document, and based on a detailed analysis of the latest scientific results, we put forward a series of action proposals that we believe would be very beneficial in the fight against the pandemic .
During this year an intense research activity has been developed and an enormous amount of information has been generated, which have allowed progress in the knowledge about the transmission routes and the most effective prevention measures. In particular, the reports published by the Ministries of Science and Health , prepared by top-level scientists and specialists, highlight the great importance of the transmission of SARS-CoV-2 by aerosols and its dominant role in indoor contagion (both at short distances such as sharing the air in a room). As clearly it indicated in these documents and in prestigious scientific publications, it is necessary to rethink prevention recommendations. In particular, there is already broad agreement to reduce the emphasis and save resources on some measures (such as surface cleaning) and give top priority to reducing the risk of infection by inhalation of the virus. The WHO has also published very clear recommendations to ensure sufficient ventilation in interior spaces, as a very effective measure to reduce contagion.
Despite the clarity of the scientific conclusions, the implementation of these measures is being extraordinarily slow, and many times it is carried out partially or incorrectly.
However, despite the clarity of the scientific conclusions, the implementation of these measures is being extraordinarily slow, and many times it is carried out partially or incorrectly. The WHO has warned Spain that it is at risk of a rebound in cases and asks that it continue the effort to limit transmission. Given the seriousness of the situation, we believe that it is urgent to take advantage of the available knowledge and promote from the administrations the necessary prevention measures to reduce the risk of contagion of COVID-19 by inhalation. We are convinced that the benefits will be enormous. Of course, in terms of the number of infections, saturation of the hospital system, long-term sequelae and deaths. But also to accelerate the long-awaited and necessary recovery of economic activity.
Many of the proposed measures can be applied immediately and in a coordinated manner. Others will require a few weeks, which makes it more necessary to start them as soon as possible. Even with successful vaccination plans, it will not be easy to achieve widespread immunization by the end of the summer, to which is added the uncertainty associated with new, more transmissible variants of the virus. There are only a few months to go, but we believe that there is still time to ensure a widespread deployment of the prevention measures available before next autumn. Otherwise, we think, it would be difficult to justify
For all these reasons, we request coordinated and urgent action by all competent administrations to address as a priority the transmission of SARS-CoV-2 by inhalation of aerosols, given its central role in indoor contagion, as has been widely demonstrated and recognized in studies.
We believe that there is still time to guarantee a generalized deployment of the available prevention measures
The eight lines of action that we consider priority are proposed below. It is an intentionally brief description, but we are at your disposal for a much more detailed analysis.
1) Masks are one of the most effective prevention tools, both for the general population and for more exposed workers. However, a determined intervention by the administration is necessary to increase its effectiveness:
Clear and concrete information on the efficacy and recommendations for use of the different masks. Identification and urgent recall of 'masks' that do not provide real protection (for example, mesh or semi-transparent, or with poor fit) and, in general, those that lack certification by a national or European body. and fit are critical. We estimate that the defects in the actual use of masks are reducing their effectiveness to less than half , which translates into a huge number of infections that could be avoided. This situation can be corrected with massive information campaigns.Require the use of masks indoors in workplaces, where indoor air is shared for many hours, even if the safety distance of two meters is maintained.
2) Since the probability of contagion outdoors is at least twenty times less than indoors, activities outside should be promoted and some measures that are counterproductive should be reviewed
Keep parks and gardens open, where the risk of contagion is very low. In addition to being a beneficial measure for the population, it will reduce indoor meetings where the probability of contagion is much higher.Promote outdoor activities when possible, for example family gatherings, work, schools, etc. There is great potential to take advantage of this reduction in contagions with the arrival of good weather. Review regulations and be vigilant with terrace spaces with enclosures that prevent ventilation, since they can be worse than traditional interiors
3) No one doubts anymore of the critical importance of outside air ventilation to reduce indoor transmission. However, the information available is incomplete and often confusing, and it is a verifiable reality that many of the activities are being carried out with incorrect or non-existent ventilation
Ventilation with sufficient outdoor air, using natural or mechanical ventilation or a combination of both , must be established as an essential measure in all activities carried out in interior spaces of all kinds, whether public or private. Ventilation must be carried out continuously . In the case of natural ventilation, it must be crossed and distributed, to guarantee its effectiveness. The ventilation rates that must be maintained must be defined. These recommendations can be expressed in terms of maximum levels of carbon dioxide (CO₂) or air flow
4) The measurement of CO₂ is the best, if not the only, low-cost technological solution available to verify at all times if ventilation is sufficient or if necessary increase it. It also allows optimizing ventilation, avoiding excessive air currents or unnecessary air conditioning consumption. In addition, it has a very low cost and constitutes a totally viable solution in any activity, public or private. Therefore, we consider its urgent and widespread implementation necessary.
5) Various air cleaning technologies are available in indoor environments, but there is confusion (even for professionals and experts) about their effectiveness, recommendations for use and possible risks. We consider that administrations must urgently assume active responsibility in this matter, addressing several aspects:
High efficiency filtering (known as HEPA filters) is a proven solution for the elimination of respiratory aerosols. However, it is necessary to clearly define the recommendations for use, the sizing and installation criteria and the specific characteristics of the equipment that the manufacturers must certify. The case of autonomous equipment should be addressed, but also the use of filters in centralized systems Recommendations on the use of other technologies, such as UV-C, photocatalysis, ionization, ozone, etc., should be clearly established. First of all, in terms of its actual effectiveness in removing viruses. But it is also essential to identify the associated risks, due to the generation of toxic substances, and take the necessary measures to protect users (for example, so that episodes of ozone use are not repeated in the presence of students), through clear regulations and the requirement for certifications that guarantee that their use does not generate risks.
6) Educational centers deserve special attention, for various reasons:
These are spaces with a high occupancy density, where the air is shared for many hours a day and most of them only have the resource of natural ventilation through windows. Until now, the centers have received ambiguous and even contradictory information. We consider it essential to implement in a generalized way optimized ventilation strategies with outside air, using CO₂ meters and continuous, cross and distributed ventilation. Both the measures that are implemented and any other training action in this area would have an enormous multiplier effect, by managing to transfer effectively to millions of families reliable information and good practices for the prevention of contagions
7) In order to achieve a generalized and effective implementation of prevention measures, it is necessary to develop criteria, procedures and regulations
Partial and ambiguous information about the Ventilation is causing great confusion and very limited and often incorrect use. It is essential to establish specific and quantitative criteria, either in terms of ventilation flow or CO₂ limits. Specifically, from official instances, the limits of 700-800 ppm (up to 1000 ppm if there is sufficient filtration) proposed in various documents should be established as reference values. It is a necessary measure to resume economic activity without generating new rebounds or the persistence of the virus at significant levels, with the corresponding health, economic and social consequences. Capacity limitations have little technical justification and should be replaced by criteria of effective environmental health interior (for example, in terms of CO₂ levels, in addition to other essential measures such as the use of masks). This must be accompanied by the development of verification and regulatory procedures (or, simply, explicit adoption and adaptation of some already existing ones), as a way to guarantee a low risk of contagion and also to provide companies and freelancers with the concrete frame of reference and stable that they need and have been claiming
8) We propose a strong commitment to dissemination , to effectively communicate the basic ideas about the transmission of SARS-CoV-2 and prevention measures. It is essential that the population understand the logic of the rules that are dictated by the administration and be able to reason what is the ideal behavior in each situation. Some measures that we propose in this line are:
Generate quality, clear and accessible information. Currently, if a person wants to be informed, they are faced with partial, confusing, sometimes too verbose and often incorrect or contradictory information … The way to offer clear, concrete, correct and organized information should be articulated, possibly with different levels of detail, accessible to any person or organization, public or private (for example, educational centers) Disseminate, through different media (social networks, TV, radio, press), institutional spaces where the main ideas are briefly and clearly explained. For example, specific messages about how the virus is transmitted, the correct use of masks or the importance of natural ventilation and how to do it, among others, could have a very positive and immediate effect.Create infographics that specifically include transmission by aerosols and associated prevention measures, for use in countless public and private places (educational centers, hotels, shops, etc.)
We put forward all these proposals after a very detailed analysis of the knowledge available on the subject, from a vocation of public service and with the conviction that its widespread implementation would have a very positive impact. We also want to reiterate our complete availability to provide more detailed information, as well as for any other work in which we can contribute.
Link to the list of signatories: http://bit.ly/Carta_COVID_Medidas