Risk reduction:

Staying safe - COVID choices and cautions

A current major concern is safe return to school. This will be addressed first. With the Oregon governor's decision to leave the choice of how to return up to school districts, we enter a time of increased pressure to return for variety of reasons. It is clear that we will return before CoVid-19 is eliminated so hopefully the goals will include:

To use science to determine the optimum time to return, balancing physical risk of returning with the economic, educational and emotional risk of staying at home.

When any type of face to face interaction happens, to practice extreme risk reduction measures to both prevent illness in students and staff and to reduce the inevitable spread in the community.

Exposure to COVID can be reduced by
Reducing the number of particles emitted into a room
Increasing the removal of particles from the room
Increasing the distance from the emitter
Blocking particles from reaching you
Limiting the length of time of exposure

COVID is spread both through near-field aerosols and droplets (within 6 feet) and far-field aerosols (from 6 feet to more than 25 feet). Under the right circumstances, aerosols (small particles such as COVID virus) may remain suspended in the air for many hours.

The primary means to stay safe is to reduce the amount and time of exposure to the virus. To do this:

Wear an effective mask at all possible times both to protect both you and others
Avoid crowded places
If indoors, increase effective ventilation to at least 5 air exchanges an hour in a room
Keep time of exposure to a minimum

PREPARATION FOR REOPENING

I am first going to focus on the risk reduction measures that could be used on school return. It is essential that we work immediately on having these available. By the time we return to school, it will be too late to get all of these in place. interventions include:use of effective masks, good ventilation, social distancing, schedule revision, habit change. Re-opening schools with relative safety requires all of these be implemented

Require masks for everyone: When everyone wears an effective mask, the risk is significantly reduced. This depends on how well the mask filters and fits. See below for a discussion of different types of masks. The challenges of mask wearing in a school setting will be discussed below under Habit Change and Schedule Revision.

Improve ventilation: Summarizing from an excellent podcast on how ventilation affects COVID spread, the goal is to increase the number of air exchanges an hour - ideally to 10 but more realistically to 5 air exchanges an hour. The standard for schools is now 3 per hour, but this is frequently not met.

Ways to increase ventilation are:

Bring in more outside air - easiest is to open a window when this is possible, or to tune ventilation systems so that they admit more outside air
Increase the filtering capacity of the HVAC system - the most attainable is to use MERV 13 filters - but many systems can't handle these. There are a variety of other things being tried such as UV sterilization and bipolar ionization, but there is little good research on their use in a school setting and the cost is significant.
Use HEPA portable air cleaners in the classroom.

As a clinical psychologist who has worked extensively in the schools and as a scientist, I am trying to channel the best science in advocating for measures that might reduce risk. At the end of this article, I will give a brief summary of some of the research I have found and also links to read further on your own.

PREPARATION FOR REOPENING

I am first going to focus on the risk reduction measures that could be used on school return. It is essential that we work immediately on having these available. By the time we return to school, it will be too late to get all of these in place. interventions include: good ventilation, use of effective masks, social distancing, schedule revision, habit change.

Ventilation: Summarizing from an excellent podcast on how ventilation affects COVID spread, the goal is to increase the number of air exchanges an hour - ideally to 10 but more realistically to 5 air exchanges an hour. The standard for schools is now 3 per hour, but this is frequently not met.

Ways to increase ventilation are:

Bring in more outside air - easiest is to open a window when this is possible, or to tune ventilation systems so that they admit more outside air
Increase the filtering capacity of the HVAC system - the most attainable is to use MERV 13 filters - but many systems can't handle these. There are a variety of other things being tried such as UV sterilization and bipolar ionization, but there is little good research on their use in a school setting and the cost is significant.
Use HEPA portable air cleaners in the classroom.

The first two interventions are limited by the design of the school and the outside temperature. The use of portable air cleaners is an effective way to reduce risk in the individual classroom. I am advocating for these to be available to every teacher returning to school. They are relatively inexpensive, more than one can be used in a classroom to meet the need, and they have a significant impact on air quality.

A good resource for more detail on practical measures to prepare is: https://www.health.state.mn.us/diseases/coronavirus/schools/vent.html

Return: A good set of questions for parents (and staff) to ask before return is offered by

I have been reading

London School of Hygiene and Tropical Medicine and UCL on testing and contact tracing in order to reopen schools:
https://www.lshtm.ac.uk/newsevents/news/2020/effective-testing-and-contact-tracing-essential-schools-safely-open-during

No increase in covid and less severe illnesses of all types in households with children through August: https://www.medrxiv.org/content/10.1101/2020.11.01.20222315v1

New strain affects children as much as adults maybe: https://www .dailymail.co.uk/news/article-9088561/Super-infectious-mutant-strain-coronavirus-likely-affect-children-claims-study.html