For the Next Heat Wave - or Smoke Wave

Our heat wave of three days of 90+ along with high humidity is over. Of course another occurrence is possible this summer. Likewise for wildfire smoke. Here’s a roundup of tips for the summer, including some ideas you won’t find anywhere else.

Photo of thermostat

Power Outages and A/C

With high heat comes high electricity demand for air conditioning, and coupled with thunder and lightning, we have a recipe for possible power outages. If you are running A/C in your house when an outage might be coming, it’s better to run it at a constant temperature all day, even if you’re gone, instead of letting the house overheat and then blasting on the A/C when you get home. This way, your house will already be cool at the start of a power outage, and you won’t be adding to the late afternoon power demand by running the A/C at 100%.

And that constant temperature doesn’t need to be 72F or lower! I have seen it reported online, as if it’s breaking news (and maybe it is), that people can be comfortable at 77F. Shocking but true. We in the building comfort industry have been preaching this for 50 years. I remember presenting a technical paper in 1978 that explained that the new-fangled oil-saving setpoints of 68F for heating and 78F for cooling can actually be comfortable, based on decades of human comfort research. 

There are at least six factors affecting human comfort, and the trick for being flexible in your comfort zone is to modify the factors under your control. For most people to be comfortable at 77 or 78F, you simply need to wear lighter-weight clothing, have a bit of a breeze from your A/C system or a small fan, and not be at a very high level of muscle activity. People also report that they like not having such a huge difference between inside and outside temperatures when going in and out.

And remember—even though you are running the A/C, you STILL need fresh air! See our blog post of July 6th, 2023 for how to make the fresh air be clean air.

Photo of N100 mask

Another Summer of Smoke?

After last summer, there has been quite a bit of research on the health effects of wildfire smoke. The results are not good. The small particles of smoke and toxic chemicals can be inhaled deep into the lungs and cause lasting effects for people, particularly those already vulnerable. See, for example:

https://www.ehn.org/people-should-take-wildfire-smoke-more-seriously

Fortunately, we have many good technologies to avoid breathing the smoke. If you HAVE to be outside, masks refined for covid-19 are very effective. See Oct. 19th, 2023 blog post.

The key trick for the simplest masks is that you do NOT have to be rebreathing your stale and CO2-laden exhaled air, since you are not protecting others from exhaled viruses. So always get a mask with an exhalation valve. This valve opens to let your exhaled air escape easily, and closes to force the incoming air to pass through the filter material. Especially if you breathe a bit deeper and slower, the valve clears out most of your exhaled breath before the next incoming breath.

The weather services are doing more now for giving air quality warnings, and good information is available via the internet, as discussed in our June 8th, 2023 blog post.

If you want your own ability to monitor your local air quality, inexpensive meters are available and reliable. I like the ones that give you a simple green-yellow-red color code (instead of the six confusing colors from the government!). My current favorite meter is: https://www.amazon.com/dp/B0CLCL9HH4

Photo of Air Quality Monitor meter

Enjoy a wonderful and safe summer in the great outdoors!


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Health in the Workplace

Here is our revised company policy on the support of employee health. It’s been a year and a half since any of us had covid-19, but here in our New England community, this spring we have seen coughs that linger for weeks, a rash of stomach flu, and air quality warnings for ozone (a new thing for us!). We made a few updates to our policy.

In Support of Employee Health

In the workplace:

• fresh air levels above 30 cfm/person (CO2 below 800 ppm)

• HEPA air purifiers above 60 cfm/person

• HEPA air filtration of incoming fresh air when there is hazardous wildfire smoke

• humidification in winter to maintain 40% RH minimum (see Dec. 1st, 2022 post)

• air conditioning, which includes dehumidification, in summer

 • masks always allowed at each person’s discretion

Blueair air purifier

Out of the workplace:

• we all take appropriate precautions depending on our risk criteria, age, vulnerability, and social needs

• we all sometimes check CO2 levels when going into questionable buildings, and want to be “in the green”

• the company provides a variety of masks for employee use to combat infectious diseases, wildfire smoke, pollen, dust, etc.

Small belt CO2 meter

COVID-19 testing:

• The company provides InBios antigen tests for use by employees before coming into the office when (1) local virus levels are above the “low” level, or (2) there has been exposure to someone with covid-19, or (3) we feel we are starting to come down with a communicable disease.

InBios Covid-19 Antigen Self-Test

During an illness:

• we stay home if we feel we might be infectious to others, and work from home if appropriate

• while we are home, we check for a fever, and we take a covid-19 antigen test every other day for the first ten days if our symptoms fit a possible covid-19 infection (for a current symptoms list, see below)

• if it’s covid-19, we encourage reducing the risk of spreading it to other family members by following the advice of this blog (see Feb. 9th, 2023 post)

We return after an illness:

• for most illnesses, after 24 hours of feeling good and with no fever, and

• for norovirus (or any type of stomach flu), 48 hours after symptoms resolve for the employee. (Note that we are treating all stomach flu as norovirus, which the CDC says is responsible for 60% of U.S. cases.) If the employee has not gotten sick, then wait 48 hours after all household members are recovered (since the incubation period is 12-48 hours), and

• if it was covid-19, after two negative antigen tests, 24 hours apart, and

• when we think we are done with transmissible symptoms, which is tricky. Per my nurse friend, and updated for covid-19 variant KP-2 (May 2024): transmissible symptoms for all illnesses include
        * fever or chills,
        * cough,
        * sinus congestion,
        * scratchy or sore throat,
        * runny nose,
        * chest congestion,
        * shortness of breath (difficulty breathing),
        * headache,
        * diarrhea,
        * nausea or vomiting.

Loss of taste/smell, fatigue, brain fog, or loss of appetite do not qualify as transmissible symptoms, nor does a lingering cough after 72 hours. However, if we think a lingering cough might mean we are contagious, we are welcome to be in the office with an N95 or better mask.

A Good Reference for Communicable Diseases

Here is a very handy chart with all the basic information. We had some contact with these folks a few years ago to suggest some covid-19 revisions.

VDH Communicable Disease Reference Chart

Meadow with flowers and sunshine

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Where We Are - And Where We Need To Go

A Graphical Perspective

For those of you into graphs, Biobot has a new Year-Over-Year option, with 2024 being in orange. You can see that the orange curve is pretty flat over the last few weeks, and is closely following last year’s curve (lime green). If we continue on this path, we’ll be at low levels of the virus for a few months. Enjoy!

A Mathematical Perspective

Last time, we shared calculations that about one of every 100 people is currently contagious with covid-19. In the Northeast, this hasn’t changed much. In the rest of the country, it’s dropped lower — now more like one of every 200 people. 

Let’s use the Northeast for an example, and expand the math. If you are having a haircut with one barber and you two are the only ones there, clearly there is a 1% chance that the barber is currently contagious. If you are having a bridge party with two tables, the odds are 8% that one or more of the eight of you are contagious. With 100 people in your grocery store, there is a 63% chance at least one person is contagious. And with 450 people or more, the odds are at least 99%.

Given this information, you can adjust your covid safety practices to suit.

A Ventilation Perspective

As you know, great fresh air ventilation can cut your risk of covid-19 and other airborne diseases by 80% or more! Yet, this convenient remedy (no vaccinations or masks required!) is almost universally ignored. If you had a choice of stores for your shopping, would you favor one with a big sign on the door that said

Welcome — Come In To
Certified and Monitored
HEALTHY FRESH AIR

and had a nice picture on the door, and a big bold meter inside showing off the “green zone” fresh air?

There are some important voices joining in this message. Here is a sampling:

- Some truth from the World Health Organization: They assembled fifty experts and produced a document recognizing the obvious — that most respiratory infections, including Covid-19, influenza and measles, are spread by aerosols that stay suspended in the air for hours, and NOT by large droplets that magically fall to the ground and don’t infect persons more that three feet away. For readers of this blog, this is not news (see Mar. 21st, 2022 blog post). “The change puts fresh emphasis on the need to improve ventilation indoors.” Now the question is whether the CDC and the rest of America will follow suit.

https://www.nbcnews.com/health/health-news/who-airborne-disease-cdc-updated-guidelines-rcna149843

- Canada is taking good air quality seriously. Here is an excellent article directed toward schools. It includes quotes from numerous experts. Epidemiologist Colin Furness said

“It won’t be cheap to improve ventilation in thousands of classrooms. But even if you don’t think protecting kids is important, you should still get behind this from a dollars and cents perspective. Consider the difference in cost between disease prevention and disease treatment. When some kids get COVID or the flu at school and come home, grandpa and grandma end up in the intensive care unit. A couple of stays in the ICU might pay for all the ventilation upgrades needed for a school.”

And he is on board with letting people know about the air quality.

“Dangerous air isn’t noticeable. Politicians, like everyone else, need to be able to see a problem to be motivated to do something about it. To help us get there, I would like to see mandated air quality sensors in public rooms and spaces. That way people could see when they board a train or bus, or go into an office or a classroom, what the air quality is actually like. If we want to have a serious conversation about air quality, we need to bring people to a certain level of literacy and awareness. To solve invisible problems, you really gotta make them visible first.”

https://healthydebate.ca/2023/11/topic/structures-are-sick-clean-air-schools/

- In the US, on CBS, 60 Minutes had a segment on ventilation in October of last year. They interviewed people who had suffered from poor ventilation, as well as several experts, including Harvard’s Joe Allen, who said

“Think about the public health gains we've made over the past hundred years. We've made improvements to water quality, outdoor air pollution, our food safety, we've made improvements to sanitation: absolute basics of public health. Where has indoor air been in that conversation? It's totally forgotten about. And the pandemic showed what a glaring mistake that was.”

https://www.cbsnews.com/news/indoor-air-quality-healthy-buildings-60-minutes-transcript/ 


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Entering the Summer Slowdown (It’s A Good Thing!)

The Summer Slowdown

If this year is like last year, we have now begun a few months with low levels of the covid-19 virus circulating in our communities. The data come from sampling sewage, and I’ve translated that into how many people are contagious with covid-19 out of every 100 people. I’ll show you the math below.

If 1 of every 100 people (or fewer) is currently contagious with covid-19, I’m going to call that a “low” level in the community. For the Northeast region (one of Biobot’s four regions), we got into the low range on March 30th. The rest of the country is even lower. 

Last year, as a national average, we were at this low level from March 11th to August 5th, as shown below in the graphs from Biobot. 

Biobot Graph of March 11th and August 5th

After that, the levels went back up as people closed up buildings to run air conditioning, and then went back to school. I expect the same thing will happen this year.

And for now, it’s encouraging that we have low levels and can gather safely in the ways in which I’ve described in earlier blogs.

Here Is the Math Summary

Several covid-19 modelers made translations from sewage sampling to case rates. I’m using the work of modeler JP Weiland, who had national new cases about 1,100 times the average copies/mL. I calculated this from the three points shown with arrows in the chart below, and correlated them with the Biobot data.

9/22/23, Biobot—640 copies, Weiland—718,367 new infections. (x 1122)
6/17/23, Biobot—168 copies, Weiland—185,204 new infections. (x 1102)
12/13/22, Biobot—1,160 copies, Weiland—1,302,041 new infections. (x 1122)

These are new infections, and we need to multiply these by the average number of days a person is contagious. There’s no easy answer, but I’m using 7 days, based in part on the chart below. 

Abbott BinaxNOW Covid-19 symptom graph

Now we can find the sewage sampling rate that leads to the figure of 1 in 100 people being contagious. It turns out to be 432 copies.

432 x 1100 = about 475,000 new infections 

divided by 333 million people in the U.S. =

about 1 in every 700 people infected today and

divided by 7 days = 1 in 100 contagious today.

Note that individual sampling sites will vary and cannot be directly compared. That is, the absolute numbers may be different, so the 1100 factor will not apply, but overall shapes of the curves will probably be similar, with perhaps even lower points to come in the next few months by a factor of two three.


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How To Find the Good Air

Readers of this blog know how important it is to spend your indoor time in places with good fresh air ventilation, which equals less virus and air contaminants of all kinds. At your indoor workplace and at your home, you have some control of the amount of fresh air, but what about all the other places you go? You can choose to frequent places with good fresh air! Here are some tips:

Fresh Air Meters

Of course, the most accurate way to tell is with a Safetulator Fresh Air Meter (see Apr. 29, 2022 blog post). These devices measure carbon dioxide (CO2) in the air. This odorless gas exists in the atmosphere in a concentration of about 0.04%, but it is in our exhaled breath at levels 100 times higher! The CO2 levels in a room come to a balance point between the high CO2 levels exhaled from people and the very low CO2 level coming in with the fresh air ventilation. The balance point - the measured concentration - can tell us the amount of fresh air per person. This is exactly what we want to know, since the more fresh air coming in (and exhaust air going out), the more this air dilutes the amount of viruses and other contaminants in the air. The Safetulator meters give simple color-coded results, and if it’s “in the green” then the air is meeting the fresh air safety standards.

The Nose Knows

If you don’t have a meter, most people can detect high air contaminant levels just by the smell. Poorly-ventilated spaces include a hardware store with a smell of pesticides, and an airplane cabin with an artificial chemical smell. Strong good smells also indicate poor ventilation, as in a restaurant with strong cooking smells, and a leather store with a strong and wonderful smell of leather.

Photo of leather store

Restaurants

Restaurants can have very good or very bad fresh air, or anywhere in between. Here is how restaurant ventilation works: Every restaurant that cooks food has a large exhaust hood over the cooking equipment. The fans in this hood system exhaust a large amount of air from the kitchen, as required by the building codes. If air goes out, air must come in, and this outdoor make-up air sometimes comes in directly to the kitchen. If this is the case, it tells us nothing about the amount of fresh air in the dining area full of people. In other restaurants, most or all of the make-up air comes directly into the dining area, and then some of the dining room air goes into the kitchen to make up for the exhaust air. In this case, the dining area can have excellent fresh air. The bigger the hood, and the smaller the dining area, the better will be the fresh air.

The Chipotle chain of restaurants is an example of the second, good fresh air design. They typically have these funky big round “nozzles” blowing fresh air into the dining area, and the CO2 levels are in the green.

Photo of Chipotle restaurant

Urgent Care Centers

Given any type of building, some will be good, some not so good for fresh air. Urgent care centers are examples. You might think that any health care operation would have good air, but that is not the case! One of our local urgent care centers has a crowded waiting room with CO2 levels that I have never measured in the green. Another one, Convenient MD, has a discrete CO2 sensor on the waiting room wall which probably means they are continuously regulating the amount of fresh air to give more fresh air when there are more people waiting, and vice versa. I have been there a couple of times, and the CO2 was in the green or right on the edge. In addition, they have an air purifier in each room, so the overall air quality that I have measured has always been well into the green. Now that’s more like it!

Photo of air purifier

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Getting Close to the Edge of the Woods

March 11th marked four years since the World Health Organization declared the “novel coronavirus” to be a world-wide pandemic. We’ll have future stories on this history and the lessons learned, or not learned, from the past four years, but for now, here is a current status report.

People walking in the woods

It’s been four years, and yet, still more than a thousand people a week in the U.S. are dying of the disease (2% of all deaths), (https://covid.cdc.gov/covid-data-tracker/#datatracker-home). The vast majority of these deaths are from the 65 million people who are either 65 and older, or those whose immune system is compromised. And among those surviving their experiences with covid-19 and vaccinations, there are at least 17 million Americans who suffer from “Long Covid”. https://www.theguardian.com/world/2024/mar/15/long-covid-symptoms-cdc

There now is a predictable pattern of increased disease during the typical winter, when people spend more time indoors (and we STILL don’t have enough improved fresh air ventilation to make a noticeable dent in the spread of airborne pathogens). People who choose to reduce their risk of another covid-19 infection continue to have good tools available (see Jan. 25, 2024 blog post).

And on the positive side, we can look forward to reduced levels of the virus in circulation, and reduced protective measures needed, starting as soon as the next few weeks.

We still have ongoing good sampling of wastewater for monitoring the levels of covid-19 and other viruses.  In New Hampshire, the graphs for Keene (brown) and Manchester (blue) show that we were at a low level last spring and summer from April through July (below the red line). So maybe only a few more weeks till we get similar conditions in both the locations shown!

And on the national level, the graphs for the Northeast (gold), Midwest (purple), South (red), and West (green) show a similar pattern of medium levels currently, and will probably continue to head downward. 

In the meantime, at whatever the levels are, keep the fresh air flowing for reduced airborne illnesses of all kinds!


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