COVID’s Collateral Damage: Germicidal Lamps May Damage Corneas:  South Florida Hospital News

Source: COVID’s Collateral Damage: Germicidal Lamps May Damage Corneas: SF STAT!: South Florida Hospital News

Since the pandemic flared in North America, I’ve had quite a few discussions about UV disinfection with media, companies, hospital staff, and various other interested people.  There are two major concerns I always try to emphasize:  

  1. UV can be an effective disinfection tool IF and ONLY IF it’s used properly (distance, time, power) and at the correct wavelengths (e.g. UV in sunlight, not so good); and
  2. UV disinfection is not safe for the “amateur” user unless it’s been properly designed and engineered into a system that prevents people from exposing their eyes or skin.

Unfortunately, there are many products now out on the market, widely available to the public, that don’t meet concern #1, or #2, or even both! Concern #1 is not so bad for the public. If someone thinks they are disinfecting something but it actually is doing nothing, then it’s more a waste of time and money than a safety issue (as long as they don’t ignore other infection prevention suggestions). Concern #2 (safety) however, is a more serious issue. And now in the media (as in the link above), we start to see reports of people with eye damage due to these inappropriate (and potentially illegal) devices. This is sad, and has potentially long-term consequences for those individuals.

My recommendation: don’t mess around with UV disinfection unless you really know what you are doing. It’s fine in commercial, hospital, and other installations where it has been properly done. I don’t recommend it for home use in rooms or those hand-held devices. For those who contact me, I’m usually happy to provide quick initial impressions on UV devices and their practicality and safety.

Microbiome Engineering

A recent edition of “Chemical Engineering Progress” (a magazine from the American Institute for Chemical Engineers), has an interesting section on “Microbiome Engineering”, as illustrated on the cover. This subject nicely illustrates the diversity of directions that chemical engineers might find in a career path.

A microbiome is essentially a community of various types of microbes that live in an environment. Most of this section discusses the human gut microbiome, those trillions of bacteria that live in our bodies in the digestive tract. Apparently, of all the cells in a human body, about 57% of them are microbial (i.e. bacteria, yeast, etc.), and the rest are human cells.

The microbiome in the gut contains about 3,000 different microbial species. In recent years evidence has been mounting that these microbes play key roles in human nutrition, metabolic diseases (like diabetes), mood disorders, and immune system regulation and disorders. Recent information suggests that people with a poor gut microbiome may be more susceptible to COVID-19 infection and severe complications, for example. There is a lot still to be learned about what constitutes a “good” gut microbiome, and how to manipulate it to improve health.

Of particular interest to chemical engineers is the question of how to manufacture so-called “living biotherapeutic products” (LBPs) that could be implanted or swallowed to modify the gut microbiome and cure diseases. Most pharmaceuticals are either chemicals (single or mixtures) or inactivated (dead) parts of microbes or viruses (as used in vaccines). Producing a living product that can grow and thrive in the gut is a somewhat new challenge, especially if it needs to be a complex mixture of microbes.

Some of these engineering/manufacturing challenges would include issues like:

  • How to shield the manufacturing process and product from oxygen, since many of these gut microbes may be negatively affected by exposure to oxygen (so-called obligate anaerobes).
  • How to get the multiple species of microbes assembled into the LBP. Grow them all separately then mix? Some may grow better in the presence of other species, due to their complex nutritional requirements and symbiotic effects. Growing mixtures of microbes is much more difficult to control if they grow at different rates.
  • How to ensure the final LBP product is consistently the same every time it’s produced. The growth history of microbes can affect their final performance and capabilities, even if they are genetically the same. What we call “process control” in chemical engineering will be crucial to consistency of products.

This area of Living Biotherapeutic Products of quite a new one, although it has certain similarities to existing industrial processes like the production of baker’s yeast or Bifidobacteria for dairy starter cultures. As the medical science evolves and promising new therapeutics are identified, chemical engineers will definitely be involved in translating these developments into manufacturing processes that meet future needs.

Rankings Again

Engineering 6 Building, Chemical Engineering

I’ve written various posts in past years about rankings and the potential problems with them, especially if secondary school students try to use them for choosing a university or program. Often, the rankings are not based on factors that actually impact an undergraduate student’s experience very much. Use the search tool in my blog to find these old posts if you want more information.

However, it’s still fun to look at rankings once in a while, and the U.S. News ones came out recently. I’ll focus on engineering rankings, which can be found at this link.

Waterloo Engineering comes out at #57 overall globally, tied with Caltech in Pasadena California. For comparison, Toronto Engineering is slightly higher at #54, and UBC slightly lower at #63. Essentially all similar, given the vagaries and uncertainties of ranking processes.

On a department level at Waterloo, Chemical Engineering made #87, while Electrical Engineering was #25, Civil Engineering was #73, and Mechanical Engineering was #49 globally. Other departments don’t necessarily show up in rankings because of the way U.S. News categorizes things. However, Waterloo ranks #82 in the “Nanoscience and Nanotechnology” category, which could include various departments in Engineering and Science.

Many of the top ranked engineering programs globally are in China, ranking above the usual U.S. and U.K. schools that you might think of. I haven’t looked at their ranking criteria, so I don’t know why the rankings come out the way they do. Just an interesting observation, and a comment on how much engineering research and activity has grown in China in recent decades.

UV Disinfection Confusion

The pandemic situation has generated a lot of interest and activity in UV disinfection, which has been keeping me busy. Whether it’s for masks, air, surfaces or whatever, there are lots of things getting posted and promoted for using UV. There seem to be an overwhelming number of devices and designs being suggested or sold online. Unfortunately there are also a lot of misconceptions, errors and possibly fraudulent claims being promoted. I’m not going to try and address each and every device (there are too many!), but I can provide some basic ideas that one should know or ask about when considering UV devices. If the supplier can’t readily provide answers or details, then something is possibly wrong. Here are a few key confusing points:

Continue reading

Classroom Air Cleaners?

Schools of all sorts are looking for ways to re-open while minimizing coronavirus transmission risks. Harvard University’s School of Public Health recently issued a downloadable document on “Schools for Health”. In it they suggest a number of administrative and engineering approaches for reducing virus transmission in a classroom and school setting. It’s interesting and worth a look.

Photo by Pixabay on Pexels.com

Since I teach and do research in some aspects of HVAC (Heating Ventilation and Air Conditioning) and indoor air quality, those parts of the report caught my attention. They are suggesting that people consider using portable air cleaners in the classroom, especially in situations where the HVAC is non-existent or poor. They don’t give a lot of numerical detail behind that recommendation, but it’s fairly easy to work it out. So I’ve done some quick calculations to see where air cleaners might be useful from a more quantitative perspective.

Continue reading

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.

Continue reading

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…

Continue reading

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.

Continue reading

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.