Do Face Masks Work?

“Plus ça change, plus c’est la même chose” (the more things change, the more they continue to be the same thing, attributed to Jean-Baptiste Karr).

Introduction to an article from the Journal of the American Medical Association, January 12, 1918

In our current pandemic situation there has been lots of confusion, uncertainty and general ignorance on the subject of face masks and reduction of disease transmission. In the screen capture I show the introductory paragraphs of an article published over one century ago, just as the so-called “Spanish Flu” H1N1 pandemic was probably starting but not yet recognized.

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Coronavirus drifts through the air in microscopic droplets – here’s the science of infectious aerosols

Here’s a nice summary article about aerosol viral transmission, by a mechanical engineering professor.  The physics of aerosols is a foundational concept in air pollution control.

Aerosols are the tiny particles of liquid and material that float around in our environment. When they come from an infected person, they may be a significant source of coronavirus transmission.

Source: Coronavirus drifts through the air in microscopic droplets – here’s the science of infectious aerosols

The Future of Chemical Engineering

Sometimes I see people getting concerned about future prospects for chemical engineering careers, usually because of some downturn in the oil and gas markets. I guess we should never stop emphasizing that chemical engineering is much more than oil, gas, and petrochemicals! There is also food, pharmaceuticals, alternative energy, environment, safety, consumer products, plastics, minerals, metals, paper & fibers, etc….

Actually, the next 30 years is probably going to be a very exciting and technically challenging time to be a chemical engineer. The world needs people with the innovation skills to handle new materials and energy processes more than ever. Why is that? Here are a few quick thoughts…

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Hand Sanitizer Blending

Photo by Anna Shvets on Pexels.com

Soap and water is a preferred choice for hand hygiene and reducing microbial and viral contamination. However this isn’t always convenient or available when out walking or shopping for necessities, so the next best thing is a hand sanitizer formulation. The nice commercial ones are in short supply, but it is relatively easy to blend your own if you can access the ingredients. Blending chemicals safely is another chemical engineering specialty. Here’s a recipe for small volumes for home use, with some discussion on the physical chemistry basis for the various components.

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Online Teaching Experience

The last two weeks of our lectures for the Winter term (last two weeks of March) were all done “online”, since the on-campus activities were shut down. This was an interesting experience, especially since we only had a week to prepare. It took quite a few hours of effort to figure out the online technology and work out different ideas and approaches before starting.

For my Air Pollution Control course, I used Webex to deliver the last two weeks of lectures live, sort of like some Webinars I’ve done in the past. These lectures were also recorded so that students who couldn’t attend “live” could look at them later. I liked the live aspect, so that students could submit questions via the chat function as we went along. I think that the ability to ask and answer questions is important, and you lose something when it can’t be spontaneous.

Luckily for me, the last two weeks of material in my course was relatively easy to adapt for online delivery. It was largely descriptive, not so much mathematical or technical. Some things that I would have normally done on the board in a classroom I had to adapt into a powerpoint deck, but it wasn’t too bad.

Delivering a whole course online is another matter, which my colleagues are scrambling to do for the term starting in May. Doing it really well takes substantial development work and a pedagogical re-think of virtually everything about the course. From what I’ve read, properly developing a truly excellent online course can take many months of preparation, audio/video recording, and editing.

Unfortunately we haven’t had a lot of time to do this, but our instructors seem to be seriously working on it as best as they can. I don’t have any courses to teach in the May-August term, but I’m keeping a close eye on how it’s done in case we are still teaching online in September when I teach another course. The university has developed a website where we can find some suggestions and other resources for online teaching. I hope we can have classroom teaching again in September, but there are some doubts and I guess we have to be prepared for anything at this stage.

N95 Masks and Re-Use

Recent pandemic developments have strained the supply of N95 filtering facepiece respirators (FFRs), which protect users from particles and aerosols in the air that they breathe. Technically, they must filter out at least 95% of 0.3 micrometre particles.

Normally these are meant to be single-use devices, and are removed and disposed of in a secure way to prevent infection transmission. However, with supply shortages people are considering or resorting to re-using these FFRs, possibly with some sort of chemical or physical disinfection process. Disinfection processes are never 100% effective, so this is not a great option, but I guess it’s better than having no protection.

One disinfection method that I’m very familiar with is UV-C disinfection, having done research in the area of photochemical processes for several decades. There is published literature available demonstrating reasonable disinfection success for UV when applied to N95 FFRs, so this may be an approach to consider if necessary.

I’m working on an overview of this literature (draft version now available at this link), but I’m happy to consult (pro bono) with health care institutions that are considering UV applications to deal with their situations (wanderson@uwaterloo.ca).

Applying to University: Done Your Homework Yet?

For those applying to university for Fall 2020 admission, there is some homework you should have done, or at least started by now. Arguably, this is probably the most important homework that you have, even if no one has explicitly assigned it or told you to do it. Properly done, this homework will make success in university more likely. So what is this homework?

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HHT Awareness Month

Every day, week and month has a charitable or other cause associated with it. June is apparently Stroke Awareness Month in Canada, which is a good thing to be aware of because so many people are affected by stroke at some point, directly or otherwise. June is also HHT Awareness Month, although not many people have heard of it. That’s mainly because HHT is one of those less common conditions listed as a “rare disease” in the NIH GARD database and elsewhere. It is actually not technically that “rare” as it is believed to affect about 1 in 5,000 people, although possibly less than half of them know it.

HHT is Hereditary (i.e. genetic) Hemorrhagic (i.e. bleeding) Telangiectasia (i.e. small blood vessel malformations in the skin and mucosal linings), also known as Osler-Weber-Rendu Syndrome after the Canadian-German-French physicians who described it in more detail in the late nineteenth and early twentieth centuries.

The most common and noticeable symptom is frequent and spontaneous nosebleeds. Other complications include gastro-intestinal bleeding, chronic iron-deficiency anemia, stroke, heart and/or liver failure, and oxygen deficiency. The underlying reason is that a genetic mutation creates a problem with one of the proteins involved in blood vessel formation, leading to malformations in the skin, nose, liver, lungs, brain, intestines and elsewhere. This mutation is autosomal dominant, meaning that there is a 50% chance of passing it on to a child.

Although it is incurable, the symptoms and complications can be managed in a variety of ways, depending on the extent and degree of severity. There are HHT treatment centres scattered across North America and Europe, as listed on a website. The trick is recognizing that someone might have HHT, as many family physicians have never seen it and may not recognize the symptoms if they do see it. This is one reason why fewer than half know that they have it. Therefore the need for awareness, so that people can be diagnosed and treated before serious complications occur. In Ontario, there is an HHT Treatment Centre at St. Michael’s Hospital in Toronto (you need a referral from your family physician).

So if you or someone you know has frequent nosebleeds for no obvious reason, or unexplained iron-deficiency, check out the curehht website and consider following up with your physician, especially if it seems to run in the family.

Spending the Carbon Budget

Everyone is familiar with the idea of a “budget”.  It’s the amount you can afford to spend or allocate on certain things.  Once it’s all spent, that’s about it unless you overspend and are prepared to face the consequences like debt or bankruptcy.

The Paris Climate Accord seeks to limit global average temperature rise to 2°C, or even better 1.5°C (it’s already risen about 1°C).  One way of looking at it is to estimate (from the physics of climate) how much more carbon dioxide we can afford to emit into the atmosphere.  That’s our “carbon budget”, and if we overspend this budget the laws of physics will make it impossible to keep the temperature rise below our desired target.

One research institute in Germany has created a nice carbon budget clock.  It shows, based on the remaining budget and the rate of “spending” (i.e. emissions), how much time we have left until the temperature target becomes an impossibility. Here is a recent screen-shot of the countdown clock (click on the link for a live version).

https://www.mcc-berlin.net/en/research/co2-budget.html
Carbon budget remaining for 1.5C target, as of May 14, 2019.

Unfortunately, there is less than 9 years until we blow the 1.5°C budget.  This doesn’t mean the global average temperature rise will suddenly jump to 1.5°C, but it means that it will eventually rise that high and there is essentially nothing that will stop it.  Like with gravity, the laws of climate physics can’t be broken.   However, if we can slow down the spending (emissions), we can stretch our budget out over a longer time.  So far that hasn’t been happening, as seen below in the emissions graph from the past 20 years.

Engineers and others have the knowledge and ideas to reduce the carbon emissions rate.  We just need the collective societal will and government leadership to do so.  Hopefully well before the carbon budget is already spent, because it will take time.  Here is a rough estimate of where the temperature is heading over the next couple of decades based on current rates.

Very rough estimate of future global average temperature rise, from Berkeley Earth project.

It looks like we will reach 1.5°C around 2040, and 2°C around 2060, unless emission rates drop significantly and soon. That won’t stop the rise, only delay it somewhat. Achieving net-zero emissions is the only way to stop the rise. Unfortunately with the current leaders (and prospective leaders) in Canada and around the world the hope for emissions reductions seems dim. So, prepare for the continuing consequences.

Waterloo Engineering is Now 529 Eligible

I’m told by our Registrar that the University Waterloo is has recently been approved by the US Department of Education.  For US residents interested in our engineering programs, this means that they will be able to use their 529 plans for tuition and some other eligible expenses at Waterloo. (For Canadians readers, this is like our RESP investments, although I’m sure there are various differences.)

We were aware that this lack of ability to use 529 plans was a bit of a barrier to some prospective US students.  I’m glad we were eventually able to remove this barrier for the future. (Thanks to our administration, as I understand this takes significant effort and time to meet all the US government documentation requirements!)

The one continuing issue is that US students in engineering will still not be eligible for US federal financial aid, because their rules don’t permit online learning as part of a program.  Our co-op engineering programs employ a work-integrated experiential learning model, where students do some small online courses during their work terms in industry.  So for now, US federal financial aid is out for engineering, but 529 plans are OK.  With the income from our paid co-op work placements,  students might not qualify for much (if any) financial aid after first year anyway.

(P.S.  all of Waterloo’s other regular programs probably qualify for US federal financial aid purposes.  It’s just our co-op programs, like engineering, that don’t at this time.)