Author Archives: hansaem jung

Replacing UV Lights with a “Green” Alternative

With summer just around the corner, it’s nearing that time of year where we start slapping on sunscreen to protect ourselves. After all, it’s well known that ultraviolet (UV) rays from the sun can damage our DNA. Despite this, UV light is still used for all sorts of applications – ranging from UV lamps at nail salons, to the hardening of resins.

A UV lamp in action. Source: cottonbro, Pexel.

The question remains: is it necessary to use UV light in these processes?

Good news: no!

Alternatives to UV light for similar processes have been recently identified by researchers. One such researcher is Taylor Wright, a graduate student at the University of British Columbia. In 2020, Wright developed a safe, low-cost method which uses harmless green LED lights instead of UV light. Wanting to learn more about this research, we sat down for an interview with Wright.

Into the details of cross-linking

The previously mentioned applications (UV lamps, resin hardening) are examples of a process called cross-linking. For an explanation of cross-linking, as well as a walkthrough of Wright’s cross-linking method of a material called polydimethylsiloxane (PDMS), please refer to the following video:

Okay… why should I care about this?

As we’ve previously said, frequent use of UV light in cross-linking processes poses a health risk to workers. By substituting with green LEDs, Wright’s newly developed method could help eliminate potential health complications in workers who deal with cross-linking processes.

But wait, there’s more! This research can also be applied to the biomedical field, through making antimicrobial fabrics. Turns out, by slightly altering the chemical properties of PDMS, we can give PDMS antimicrobial properties. By dipping a piece of fabric into liquid PDMS, then cross-linking to produce a solid PDMS coating, we can produce antimicrobial fabrics! The diagram below helps visualize the process.

Step-by-step walkthrough of making the antimicrobial fabric. Source: Wright’s 3MT

This would have important implications for reducing the rate of infections in high-risk settings, such as hospitals. In the US alone, there are approximately 100,000 deaths resulting from infections acquired in a healthcare setting. Considering the COVID-19 pandemic that we’ve been in for a whole year now, this application has never been more relevant. Wright’s low-cost, simple, and safe method of producing antimicrobial fabrics could be crucial in reducing the impacts of any future pandemics.

Beyond the research

Although we learned much about his research during our interview with Wright, we were also able to get a glimpse into the person behind the science. To hear about his journey that resulted in the person he is today, listen to this week’s episode of Vancity Science, a podcast run by one of our members, Chie!

Audio sources: Blue Dot Sessions, Free To Use Sound – Royalty Free Sound Effects, Kyster, SnakeBarney, dobroide, KelliesKitchen, ZyryTSounds, ShadyDave, InspectorJ

 

Special thanks to Taylor Wright – we are excited to see further innovations by scientists with unique perspectives that can make the world a safer and better place!

– Sam Jung, Chie Nakayama, Madeline Filewych

Reusable Grocery Bags… It’s Complicated

I hope you don’t like your groceries in a plastic bag, because that may be a thing of the past very soon! As the world looks to reduce plastic waste, many countries have banned the use of single-use plastic bags – with Vancouver to follow suit by 2021. Greener alternatives—biodegradable or compostable (BoC) plastic bags, paper bags, reusable plastic bags, and cotton totes—have been steadily becoming more popular for many shoppers.

Some alternatives to single-use plastic bags. Adapted from Plastic Education.

But what’s really the truth? How much better are these so-called greener alternatives?

What if I told you that the chic tote you bought for yourself is actually much, much worse for the environment than a plastic bag?

What’s it take to make these bags?

To get a good grasp of the environmental impact these bags can have, we need to look at the full picture. Turns out, the bulk of the environmental impact of these bags come from the production stage. Let’s have a quick overview of how each type of bag is made.

The single-use plastic bag—in all of its environmentally unfriendly glory—is produced from petroleum. The thicker, reusable plastic bags are also made from petroleum, except they require quite more. On the other hand, we make BoC plastic bags from plant-based materials such as starch! Wood pulp is required for paper bags, and of course, cotton (which requires loads of resources) is needed to make cotton totes.

A cotton field. Source: Jimmy Smith, Flickr

So how does this play into the environmental impact?

There are many studies called life cycle assessments (LCA) which examine how a product is made, used, then disposed of. In 2018, the Denmark Environmental Protection Agency conducted a LCA of the different types of grocery bags. For each type, they looked at the total environmental impact (greenhouse gas release, ozone depletion, water depletion, toxicity, and more).

“Greener alternative”… well, no, not really.

The big question is, how many times do you need to use your reusable bags in order to have less impact than if you used single-use plastic bags?

You might want to hold onto your seat. For the total environmental impact, you’d want to use your BoC plastic bags, paper bags, and reusable plastic bags at least 40 times in order to beat single-use plastic bags. And for the cotton tote? You would need to reuse it 7100 times. It’s even higher for organic cotton, since organic crop yields are lower: try 20000 times. If you use your tote three times a week, it would take 45 years (128 if organic) to break even with single-use plastic bags!

It’s intuitive to think that the greener alternatives would be better for the environment. Single-use plastic bags do not break down, and end up in landfills, whereas alternatives could be either biodegradable or used many, many times before they break and become unusable. It goes to show that it’s important to consider not just the disposal of a product, but also the production and resources that go into making it.

For more information, check out this video from SciShow!

 

-Sam Jung

Need to Sober Up? Just Breathe Out the Booze!

With regards to alcohol, many of us have previously reached the so-called point of no return: a moment where the pleasant buzz is replaced by a throbbing headache (and massive amounts of regret). If only there was a simple way to quickly sober up…

Alcohol! Source: awee_19, Flickr

A simple overview of ethanol breakdown

First, let’s dive into how our bodies break down alcohol. Once ethanol arrives at the stomach and intestines, it is absorbed into the bloodstream. From there, most of the alcohol ends up in the liver. The liver is responsible for detoxifying 90% of the ethanol that we consume; the remaining 10% is eliminated through sweat, urine, and breath.

However, the rate at which the liver breaks down ethanol is zeroth-order: meaning that the breakdown rate is always constant, no matter how much ethanol is in your system. This explains why we haven’t been able to develop techniques to speed up the rate of ethanol breakdown in our livers.

Naturally, the next step would be to see whether we can speed up the elimination of the remaining 10% of ethanol in our bloodstreams. Turns out, we can! Remember how we said that some ethanol is breathed out? This works the same way that we exhale carbon dioxide: diffusion! Since the ethanol concentration in our bloodstream is higher than in the air that we breathe in, some ethanol diffuses into our lungs and we breathe it out!

Diffusion Explained.
Source: Free Animated Education, YouTube

A breathalyzer uses the fact that we breathe out ethanol to determine our blood alcohol concentration (BAC). Source: Dave Shea, Flickr

So can I just hyperventilate until I start to feel sober?

In theory, you could… but you really shouldn’t. Hyperventilating will reduce your ethanol levels, sure, but it will also decrease your CO2 levels: causing your brain’s blood vessels to narrow, and ultimately depriving your brain of oxygen. Thankfully, a recent study has found a simple and effective solution, utilizing isocapnic hyperpnea.

Isocapnic hyperpnea: what is it?

To put it simply, isocapnic hyperpnea (IH) is when you deeply (sometimes rapidly) breathe in air that has an equal concentration of carbon dioxide as in your bloodstream. This lets you breathe out all the nasty ethanol, while your CO2 levels stay steady. In the study, participants drank vodka, then were connected to a device which supplied air which had a CO2 concentration similar to what would be found in normal blood vessels. The results of the study showed that the participants who underwent IH were able to get ethanol out of their system more than three times faster than participants who breathed regular air!

A demonstration of the IH apparatus. Source: UHN

This technology could be widely available in the near future, since IH has already been approved as a treatment for clearing our bodies of other chemicals. IH could help paramedics in clearing the alcohol out of a patient’s system in a timely manner, which could ultimately save their lives. Remember to always drink responsibly!

 

– Sam Jung

Need to Sober Up? Just Breathe Out the Booze!

With regard to alcohol, many of us have previously reached the so-called point of no return: a moment where the pleasant buzz is replaced by a throbbing headache (and massive amounts of regret). If only there was a simple way to quickly sober up…

Alcohol! Source: awee_19, Flickr

A simple overview of ethanol breakdown

First, let’s dive into the details as to how our bodies break down alcohol. Once ethanol arrives at the stomach and small intestine, it is absorbed into the bloodstream. From there, it can travel to various organs in your body, or end up in the liver. The liver is responsible for detoxifying 90% of the ethanol that we consume; the remaining 10% is eliminated through sweat, urine, and breath.

However, the rate at which the liver breaks down ethanol is zeroth-order: meaning that the breakdown rate is always constant, no matter how much ethanol is in your system. This explains why we haven’t been able to develop techniques to speed up the rate of ethanol breakdown in our livers.

The next natural step would be to see whether we can speed up the elimination of the remaining 10% of ethanol in our bloodstreams. Turns out, we can! Remember how we said earlier that some ethanol is removed via breathing? This works the same way that we breathe out carbon dioxide: because the concentration of ethanol in our bloodstream is higher than in the air that we breathe in, some ethanol diffuses into our lungs and we breathe it out!

A breathalyzer uses the fact that we breathe out ethanol to determine our blood alcohol concentration (BAC). Source: Dave Shea, Flickr

So can I just hyperventilate until I start to feel sober?

In theory, you could… but you really shouldn’t. Hyperventilating will reduce your ethanol levels, sure, but it will decrease your CO2 levels as well: causing your brain’s blood vessels to narrow, and ultimately depriving your brain of oxygen. Thankfully, a recent study published just last year has found a simple and effective solution, utilizing isocapnic hyperpnea.

Isocapnic hyperpnea: what is it?

To put it simply, isocapnic hyperpnea (IH) is when you deeply (and sometimes rapidly) breathe in air that has an equal concentration of carbon dioxide as present in your bloodstream. In the study, participants consumed diluted vodka, then were connected to an apparatus which supplied air of CO2 concentration similar to levels found in normal blood vessels. This allowed the subjects to breathe out ethanol at a higher rate while maintaining steady CO2 levels in their blood. The results of the study showed that the participants who underwent IH showed an ethanol elimination rate which was more than three times greater than participants who breathed regularly!

A demonstration of the IH apparatus. Source: UHN

Deaths caused by alcohol poisoning are far too common. In the future, IH could help paramedics in clearing the alcohol out of a patient’s system in a timely manner, which could ultimately save their lives. Remember to always drink responsibly!

 

– Sam Jung