Friday, 15 May 2015

Careers In Chemistry: Forensic Science

Hi again, everyone! Now we're through all of our unit posts, it is time to take a look at what options are out there for those interested in pursuing chemistry as a career. Hopefully the posts on this blog and all the others, have inspired you to realize how multi-faceted chemistry is and how much behind the scenes work it plays in our daily lives. So unsurprisingly, there are a lot of jobs out there concerning chemistry! Today we're going to highlight forensic scientists - specifically forensic chemists - and why their job is awesome!

Read on to find out WHAT forensic science is, WHO is doing it, WHY it's an awesome chemistry career, HOW to get a job doing it, and WHERE to study.

So what is forensic science? Forensic science is the study and analysis of physical evidence and samples to help law enforcement solve crimes. Using a variety of techniques and processes, forensic chemists unravel and reconstruct what actually happened at a crime scene based on evidence provided. A well trained, advanced forensic chemist should be able to determine the composition and nature of materials, predict the source, and match sample to sample. Forensic science encompasses organic and inorganic analysis, toxicology, arson investigation, and serology. Most of the time, samples are not handed over as pure substances, but rather often mixed in with dirt or other gross stuff. One of the toughest and most exciting parts of forensic science is separating out these individual components and figuring out what went where (Massey, 2009). Pretty cool, huh?

Who are the notable players in the field of forensic science? Any Canadians up in there? Professor Tracy Rogers, director of the forensic science program at the University of Toronto, is one of the leading forensic scientists in the world. She is the lead forensic anthropologist at the Pickton pig farm in B.C, the largest crime site in Canada and also worked on the Tim Bosma mystery case. She works on the identification of unknown skeletal remains, skeletal sex determination, skeletal techniques for assessing the ancestry/biogeographical origin of the deceased, and the positive identification of decomposing human remains. She also researches the application of new technologies to the analysis of outdoor crime scenes and hidden graves (University of Toronto, 2012).

Why is the world of forensic science a good career option for those interested in chemistry? Forensic science encompasses many scientific disciplines, including chemistry, biology, physics, and anthropology. It's a study that demands excellence, intelligence and innovation (Maclean's, 2011). It's rigorous and demanding work, for sure, but extremely rewarding. You're literally helping to catch criminals and solve major crimes! For example, some of Dr. Tracy Roger's work at the Pickton pig farm involved 'trawling' for remains over a 14 hectare site and a 16 hectare, sorting out human bones from animal, those relevant to the case, etc...She went in looking for around 69 sets of bones! Then she had to distinguish between whose bones were belonged to which individual. It can be very grim or even disgusting to some people, when dealing with cadavers or decomposing organisms. But how rewarding would it be, returning bones to their rightful owners, giving families back their children? You may even find yourself applying some of the lessons we learned in this course; qualitative analysis comes to mind for sure - figuring out what components are in a substance.

How do you get a job in the field of forensic science? Interestingly, TV shows such as Bones and CSI have popularized the once considered 'gruesome' profession. This means fierce competition for positions. Typically, forensic scientists will work in tandem with a government agency such as CSIS or the FBI, or in an independent forensic lab, in a medical examiner's office, hospitals, or teach at universities or colleges. Most institutions require at least a masters degree, but to teach or direct at a crime site, a doctorate is required. The typical career path of a forensic scientists is as follows:
- B.SC in biology, biochemistry, chemistry, or any other science discipline
* a degree in forensic science is not necessarily required, but would be an asset
- A Master's science degree
- A PhD in a certain discipline of science
All of these steps are not necessary for all jobs, but to reach the highest pay level and most responsibility it is recommended.

Finally, where should you study? Is there some kind of accredited school on how to be a dead people doctor? The short answer, is NOPE! As stated above, a degree in forensic science is not necessarily required, though a strong science background is. Pretty much every university in Canada offers a myriad of cool undergrad science courses and any one of those would be great. For example, doing your Bachelor of Science in Microbiology at Carleton, or your Bachelor of Science in Organic Chemistry at Queens...there are plenty of options. If you want a more specific look at forensic science, there are a few faculties that offer a dedicated program. University of Toronto, for example, is one of the few. They offer courses at the undergrad, masters, and post doctorate level.

Hopefully this post educated you on the field of forensic science! Who knows, maybe you two will experience some chemistry (haha). I hope you enjoyed reading through some of my posts on our curriculum this year, and thank you for getting through it with me. I encourage you to continue on the science path to post secondary and even further!

Good luck out there, kiddos!

Friday, 8 May 2015

Unit 5: Go Local...or Maybe Not?

In Unit 5 of our Gr. 11 chemistry course we explored gases and atmospheric chemistry. We learned about the dangers an excess of carbon dioxide has on our environment. We are the main producers of carbon dioxide, which is one of the main contributors to climate change.

The local food movement has really taken off in the past 10 or so years. It's claimed benefits are driving health and environmentally conscious consumers away from the aisles of their local Loblaws and down the gravelly paths of their neighbourhood Farmer's Market. An Iowa based study, led by Dr. Rich Pirog, found that, on average, produce travelled about 1,500 miles before reaching dinner plates. Conversely, locally sourced food was found to typically travel less than 50 miles from farm to table (Pirog, 2008). Really, the concept of 'eating local' seems pretty common sense. Produce is fresher and riper, local farms are supported, gas emissions from transportation are drastically reduced, and everyone is happier. In fact, a Canadian study estimated that replacing imported food with locally grown/produced items would save nearly 50,000 tons of transport related carbon dioxide emissions - or taking over 15,000 cars off the road for good (World Watch Institute, 2013).

But WHAT is actually local food? Are green peppers grown in Kingston local to us in Ottawa? They're a lot closer than California, that's for sure - but what does that mean? This is one issue with trying to figure out whether or not the green food movement actually is greener - there is no long standing definition of what local food really is. Since the publishing of the '100 Mile Diet' and other such books, 100 miles or just over 150 km is seen as the typical boundary. "A 100-mile radius is large enough to reach beyond a big city and small enough to truly feel local. And it rolls of the tongue much more easily than the 160-kilometer diet" (Alisa Smith, 2009). This seems like a perfectly valid way to think about local food, but it doesn't have much to do with environmental costs and benefits.

Food miles, in some cases, don't actually determine how environmentally friendly the product may be. For example, trains are 10 times more efficient at transporting cargo than freight trucks. So eating potatoes from 100 miles away transporting by truck, or eating potatoes from 1000 miles away transporting by train have pretty much the same amount of emissions. It's also important to note how a foods are grown and what impacts that process may have. Swedes, in fact, are better off eating tomatoes grown in Spain than down the street, because Spanish tomatoes are grown in open air fields, while their own must be grown in fossil fuel heated greenhouses (Annika Carlsson-Kanyama, 2012).

Or maybe not? 

To get a true, comprehensive scope of the environmental impacts caused by our food system, you have to track the greenhouse gas emissions through all phases of the food's production, transportation and consumption. This method was created by two scientists, Weber and Matthews, from Carnegie Mellon University, who coined the process 'life cycle analysis'. They weaved together data from environmental agencies, trucking call sheets, and a variety of other US government sources to discover that the actual transportation accounts for only 11% of the total emissions. The two found that the most emissions actually occur before the food even leaves the 'farm' gate - over 83% of emissions occur from agricultural production (Drs. Weber and Matthews, 2009)!

Another clear pattern that emerges, according to Dr. Garnett from MIT, is that the type of food in question can have a big impact. In fact, the emissions generating from the meat and dairy industries account for more 53% of all food related emissions worldwide (World Watch Institute, 2012) and much more than all transport emissions globally. "Broadly speaking, eating fewer meat and dairy products and consuming more plant foods in their place is probably the single most helpful behavioural shift one can make to reduce food-related greenhouse gas emissions" says Garnett. Weber and Matthews point out that even if food miles were reduced to 0 - an almost impossible goal, by the way - this would only reduce emissions by 5 - 11%, but replacing red meat and dairy with fish, eggs, or even chicken one day a week   is the equivalent of saving 760 miles of driving emissions. Even better, replacing meat or dairy with veggies one night a week would be like driving 1, 160 miles less. Wow!

Now, all of that said, let's return to this concept of 'eating local'. What we didn't discuss earlier are some un-food mile related benefits that locavore eating can bring about. Local foods are often seasonal and much less processed, both of which are associated with lower green house gas emissions than conventional foods. Local foods found at farmer's markets or from CSAs are also often organic, which typical is greener, as the emissions produced by the creation, transportation and application of chemical fertilizers are eliminated. Organic food also has some other benefits; less use of toxic anti-pesticides and other chemicals is much easier on ecosystems and encourages greater biodiversity, organic fields require less irrigation (normally). Additionally, local farmers are typically smaller scale and can therefore adopt more sustainable practices to meet market need (Wolfe, 2003). Let's not forget about the relationships and community eating local can foster either - knowing where you food is coming from and meeting the grower face to face is quite remarkable.

As local food is so often discussed only in terms of it's mileage, we tend to forget about it's other benefits - but as Gail Feenstra says (a food analyst at the University of California), a food's carbon footprint "can't be the only measuring stick of environmental sustainability". According to local food advocate Sage Winn, eating local is about "how those [foods] were farmed, how the farm workers were treated" - a sprawling collection of ecological, societal and economic factors combine to form true sustainability (Winn, 2003).

In my opinion, eating local is a pretty cool thing to do. Going vegetarian or vegan, even one night or two a week, is also a fabulous option for reducing your carbon footprint. My Mom and I actually shop at our local farmer's market every Sunday morning - for the yummy foods, the sense of community, and honestly, how much fun it is! As Canadians, going local is a little harder in the winter, when our only 'local' produce are pretty much potatoes and last season's apples!


1. Would you go local? Why or why not?

2. What's your opinion on food miles? Do YOU think they're important?

3. Explain why carbon dioxide emissions are so bad for the environment? Carbon dioxide seems pretty normal, right?

Wednesday, 29 April 2015

Unit 4: Nano Particle Solubility and the Environment

 Okay, hold up, what the heck are nano particles?! How do they relate to solubility?? Well, nano particles are microscopic particles where at least one dimension is less than 100 nanometers (nanometers are one billionth of a meter) and they have a narrow size distribution. Basically, they're extremely small bits of stuff. Dr. Ananya Mandal from MIT defines them as "a small object that behaves as a whole unit in terms of its transport and properties." Nano particles are used in multiple different ways, primarily in the biomedical, optical and electronic fields - but also in some ways you'd never expect!

Applications of nanoparticles 

One cool way that nano particles are used is within your own clothing! Silver nano particles are often added to fabrics due to their ability to kill bacteria. They are also commonly found in cosmetics, soaps, personal care products, etc. When oxidized, the nano particles shed toxic silver ions, which knock off any bacteria. Theses charged ions of silver can interfere with important processes in living cells. As a result, key populations of bacteria and microorganisms could be severely damaged or mutated in soils and aquatic environments. This is concerning because when these ions reach the environment and dissolve, they could have harmful effects on the ecosystems upon which our food system depends. And as our global population grows, the release of silver ions into the environment is also expected to expand, via waste treatment and industrial processes.
Pathways by which man made particles are released into the environment. 

As well, bacteria aren't the only species at risk from the dissolution of silver ions. Larger creatures could directly or indirectly ingest them as well, for example, through the gills of a fish or the skin of a frog. We ingest them as well, through our food but also absorb them through our skin and breath them into our lungs. For larger animals however, the effects of silver ions has not been thoroughly studied and most likely varies based on mass, species and numerous other variables. As such, further research is needed to truly asses the dangers of silver ions on our environment.

Some ways nano particles can affect our bodies

Recently, scientists Peter Vikesland and Ronald Kent from the Virginia Polytechnic Institute have developed a new technique to study how nano materials dissolve in aqueous solutions. The goal is to help other scientists predict the effects of these nano particles on the environment and design safer materials. Other studies have examined the effects of groupings of nano particles, but not the singularly. Seems like it wouldn't matter, but think about it this way: a single snowflake melts a lot faster than a shovelful of snow. Their new technique focuses on how the particles dissolve alone to figure out how fast each individual one could shed ions. The biggest advantage to the procedure is that it allows the particles to be studied at similar concentrations found in the environment. Their conclusions will then be much more useful in the "real world".

The researchers fix silver nanoparticles at intervals along a glass surface, then expose them to different concentrations of sodium chlorides for two weeks. Then they examined changes to their size and shape. Their results suggest that chloride speeds up the shedding of silver ions from the particles, without forming sodium chloride. Dr. Bernd Nowack, a chemical engineer from the Swiss Federal Laboratory for Materials Science and Technology, says he can "envisage it eventually being used directly in the environment, in rivers or wastewater, for instance."

In my opinion, as dry as it sounds, this new technique seems to be pretty interesting! Especially with our growing global population and increasing pollution levels, understanding the effects of the materials we're using is very important. I find it pretty hard to believe that all these substances, not just including nano particles, are currently used without a comprehensive analysis of their long term environmental or health consequences. I also believe that more research is needed to fully understand nano particles and the effects of silver ions on the environment. Further studies are also needed to explore the effects on other basic forms of marine life; algae for example, or water fleas, as some experiments on them have shown that the individual coatings on different nano particles could be a 'driving factor of the toxicity'.

My questions to you: 

1. Why do you think silver nano particles would shed ions? What is this process called?

2. Can you think of any other applications of nano particle research? Why is this field so important?

3. Why does it matter if some bacteria get a little mutated or die off? We don't eat bacteria, right? So why should we care?

4. What would you tell someone who didn't believe in the risks of silver ions?

Monday, 27 April 2015

Unit 3 - Airbags: Friend or Foe?

Welcome back! In Unit 3 of chemistry course, we delved into the exciting world of stoichiometry, mole calculations, percent composition, percent yield, and all sorts of other new ways to calculate stuff. Today we're going to discuss a real world application of stoichometry (quantities in chemical reactions) and take a look at why this stuff matters outside a lab.

Airbags save thousands of lives each year in the States and here in Canada. But even after more than 2 decades after they've become mandatory in most cars, the auto industry still struggles to master the complex systems that must work flawlessly in less than a second. The recent recall of Takata air bags and General Motor's recall of their ignition switches highlights the problems that can occur when airbags actually deploy and when they don't.

A rundown of what actually occurs when airbags expand
Airbags are known for being extremely delicate and complex systems. The bag itself is made of thin nylon, which is folded into the steering wheel, dashboard, seat, or door. The sensor, typically located inside the dashboard, tells the device when to inflate. This happens only when the sensor detects collision force equal to running into a brick wall between 16 - 24km/hr. When this occurs, the airbag system ignites a solid propellant (similar to a rocket booster), which burns very quickly to produce huge volume of gas (ammonium nitrate). The gas then fills the nylon bag and literally bursts from its storage place into the vehicle at over 200mph.

Takata airbags, found in many new cars on the market today, have been recently recalled after new evidence came to light about the dangers they pose to drivers and passengers. Over 100 injuries and 5 deaths have been due to the airbags, who send metal shrapnel flying when deployed. Despite extensive research, a single cause has not been identified. Some suspect the ammonium nitrate itself, only recently used in their airbags, and hailed as a "new technological edge" by a company engineer (Paresh Khandhadia, 2009).

According to experts, ammonium nitrate breaks down over time and is very sensitive to temperature changes and moisture. Under these conditions, they say, it can combust violently (Hiroko Tabuchi, 2014). Interestingly, it becomes unstable at about 100 degrees. The inside of a car in summer may get as warm as 140 degrees! But it's cheap. Unbelievably so. Some say the switch from sodium azide (as seen in the inflation device diagram) to ammonium nitrate in 1998 was not for cost reasons, but for the environment. Ammonium nitrate produced gas much more efficiently with fewer emissions in their trials, says Alby Berman, a spokesperson for the brand. Either way, the company continues to use ammonium nitrate in their replacement air bags.

Another theorized issue is the quantity of ammonium nitrate involved in the equation. The New York Times published a video in 2014 depicting scenes of dropped air bag 'kits' and other mishaps on the assembly line. Sources who wished to remain anonymous told the newspaper that there was such enormous pressure to keep with demand, that sending potentially defective or damaged product back was not popular with management. If the amount of ammonium nitrate varied even a little from bag to bag, this could severely impact the resulting chemical reaction. As studied in stoichiometry, a change in the amount of reactants can completely alter the reaction itself. These unknown changes are not something you want coming at your face or your family's faces at 200 mph.

In my opinion, Takata is playing with fire. Using ammonium nitrate may be cheaper and 'produce less emissions', but at what cost? It seems almost crass to continue using the compound when it may or may not be involved in many deaths and injuries. Personally, I'm grateful neither of my parents cars use Takata airbags. Even though we've never been in an accident, it's still much better to know we won't have shrapnel coming at us inside our own car. I hope as much effort as possible is put into researching the cause of these malfunctions and correcting it. At the very least, ensuring quality product off the assembly line is a good first step.

My questions to you:
1. Do the benefits of ammonium nitrate outweigh the costs, in your opinion? After all, they don't ALL explode.
2. Should Takata have recalled only the airbags from cars registered in more humid/warm cities? Why or why not?
3. Compare sodium azide to ammonium nitrate. Why is sodium azide purportedly safer?
4. If you could give a piece of advice to the CEO of Takata, what would it be?

Sunday, 19 April 2015

Unit 2: Chemical Reactions within the Human Body

Unit Two of our Gr.11 chemistry course examines the different kinds of chemical reactions and how they may be used in variety of applications. Little do we notice, but these kinds of chemical reactions occur constantly within our very cells. These reactions keep us alive, maintain our pH, digest our food, and produce lots of energy.

Here we'll discuss step one in cellular respiration for eukaryotic (or more highly evolved) organisms, which is often the only step of cellular respiration in prokaryotic organisms. Cellular respiration is process of oxidizing molecules of glucose and trapping the energy produced in ATP. ATP, or adenine triphosphate, is basically the molecular currency of energy transfer. It's phosphorylated (sticking another phosphate on) from ADP (adenine diphosphate), storing energy in that chemical bond.

Before describing the series of chemical reactions that take place in glycolysis, step one of cellular respiration, let's talk about the two ways cells convert chemical potential energy from one form into a new one.

1. Substrate-level phosphorylation:
This happens directly in an enzyme catalyzed reaction, when ADP is phosphorylated into ATP, as explained above. During the process, about 31kJ/mol of potential energy is also transferred.

2. Oxidative phosphorylation:
This happens indirectly through a series of sequential redox reactions. It's a lot more complex than substrate-level and gives up plenty more ATP. The steps in the actual reaction are numerous and pretty complicated, so we won't get into them here.

An overview of the processes involved in cellular respiration and their location within the cell. 
Glycolysis is an ancient process that is believed to have evolved millions of years ago in single celled organisms, like yeast and some bacterium. It occurs in the cytoplasm of your cells. If you think about, its name tells you exactly what it does. Glyco - sugar, lysis - splitting/breaking. Basically, glycolysis takes a molecule of glucose, which has 6 carbons, and splits in half, producing two 3 carbon sugars, then later pyruvate and some ATP. This occurs in 10 enzyme-catalyzed steps. The first four steps essentially are composed of re-arrangement of molecules. Glucose is rearranged into fructose, etc. Steps 6 - 10 occur twice, once per 3 carbon sugar. The end result is pyruvate and some ATP.

After glycolysis, three other processes occur to round out cellular respiration. We won't get into them all here, as that's pretty much a whole unit of biology, but I encourage you to continue taking Bio and learn more about cellular processes. Photosynthesis is also covered, which is super cool as well. If you think you might be interested in this kind of material, but in greater depth, you should definitely think about continuing in biology or biochem. 

This information is mainly biology based, but it is pretty cool to see how the two sciences intersect. We've got a lot of organic chemistry going on here too! I find it can be hard to think on such a tiny level - within a cell, within an organelle, within a particular part of an organelle! Crazy. I also think that it is important to understand what processes occur in your body, where and why. Learning more about the body's complexity makes me even more in awe of how amazing they are and gives me an even deeper respect for them. 

My questions to you: 

1. Identify the type of chemical reaction that occurs in step 4 of glycolysis. How do you know? 
2. What do you think the next step of cellular respiration would be? Why? 
3. Why do we need to 'spend' ATP to get glycolysis going? Is there a way around that? 
4. Explain why catalysts are important throughout glycolysis. What's their purpose? 

Thursday, 26 March 2015

Unit 1: A Link Between Chemicals in Antiperspirants and Breast Cancer?

Unit 1: Chemicals and Breast Cancer?! 

Hi! Welcome to my chemistry blog assignment for Mrs. Casimiro. My name is Kate Reeve.

Unit One of our Gr. 11 Chemistry course discusses the properties of common chemical substances and their impact on our health and our environment. In fact, the chemical compounds studied in class can frequently also be found in household products, such as cleaners, soaps, shampoos, and deodorant. These chemicals, classified as parabens if used as preservatives in cosmetic and pharmaceutical products, are then often absorbed into our skin or breathed into our lungs. Parabens are known to mimic the hormone oestrogen, which can drive the growth of tumours.

Here we'll examine the effects of antiperspirants on breast health. First off, how do antiperspirants even work? Why would they be linked to breast cancer? Well, antiperspirants essentially work by clogging the pores that release sweat under your arms, typically with aluminum salts. These salts account for more than 25% of most antiperspirants. After the product is applied, the chemical is absorbed into breast tissue, often at a rate of 0.012% per application. Seems like nothing, but multiply that by at least one time a day for an entire lifetime and suddenly you've got a staggering amount of aluminum in your boob/bod. Not good, especially as aluminum salts have been proven to act similarly to cancer-causing genes, also known as oncogenes.

Recent research conducted by Dr. Philippa Darbre and later reviewed in the Journal of Applied Toxicology has linked the parabens found in most antiperspirants with an increased risk of breast cancer. This theory (as it has not yet been resolutely proven) hinges on two main points:

1. Breast cancer is on the rise, with more and more cases each year. This corresponds with the societal changes undergone in those same years; namely climbing rates of personal care products containing untested chemicals.

2. The majority of all malignant breast tumours are found in the upper, outer quadrant of the breast; also known as where you apply antiperspirant. As well, more tumours are found in the left breast than the right, which if you think about it, also makes sense. Most people are right-handed, which means they'd likely be able to apply more product to that side than the other unconsciously.

The final evidence is a separate study conducted by Dr. Barr and team, which discovered that ninety-nine percent of breast cancer tissue contains parabens.

However, the authors of the review in the Journal of Applied Toxicology are quick to note that while antiperspirants are a common source of parabens, the source of the parabens cannot be established and that 7 of the 40 patients studied never even used commercial antiperspirants in their lifetime! This means that parabens, regardless of their source, can bioaccumulate in breast tissue.

Think about all the products you use - maybe makeup, moisturizer, deodorant, face wash, hand soap, shower gel, etc. All of those products and applied topically (to your skin), which is, unfortunately, the most efficient way parabens are absorbed. You might be wondering why, if parabens are so bad, are they still being sold to us in simple packages of face soap? Well, believe it or not, the safety of parabens as never actually been proven and the toxic effects of the chemicals on humans has never been thoroughly investigated.

Personally, I find this information to be pretty compelling. It may be circumstantial, but the truth is that there just haven't been enough studies to concretely link parabens and an increased cancer risk. Therefore, in the words of Dr. Harvey and Dr. Everett (two prominent cancer researchers) "[the argument that no evidence linking the two has been proven] provides false assurance by masking the inadequacies of empirical evidence and knowledge." I know antiperspirants can be pretty helpful, but maybe try to use natural, aluminum-free deodorant, for the sake of your health. Even though none of this has been absolutely proven, why risk it?

My questions to you:

A) List some properties of aluminum salts (specifically hydrated ones) and give the chemical formula. Based on what we've learned about chemical properties in class, can you relate any of the properties you found with potential health problems?

B) Why do you think such little research has been done into the relationship between the parabens and cancer?