Quick Links

Feed aggregator

Hazard and risk

Our OSS Blog - Thu, 11/26/2015 - 19:19

If you watched the news, read newspapers or surfed the web recently you will have been inundated with pictures of bacon and headlines describing it as carcinogenic. That’s because the International Agency for Research on Cancer (IARC) classified processed meats as being carcinogenic, placing them in the same category as tobacco smoke, asbestos, oral contraceptives, alcohol, sunshine, X-rays, polluted air, and inhaled sand. However, it is critical to understand that the classification is based on hazard as opposed to risk. Hazard can be defined as a potential source of harm or adverse health effect. Risk is the likelihood that exposure to a hazard causes harm or some adverse effect. If a substance is placed in IARC’s Group 1, it means that there is strong evidence that the substance can cause cancer, but it says nothing about how likely it is to do so. That likelihood depends on several factors including innate carcinogenicity, extent of exposure and personal liability. Ultraviolet light, a component of sunlight, is a good example to illustrate the difference between hazard and risk

Light can be thought of as being composed of packets of energy called photons. When a photon impacts a molecule of DNA it can damage it, triggering an irregular multiplication of cells, in other words, cancer. X-rays are also made up of photons, but these are more energetic than the photons of ultraviolet light so they are more likely to damage DNA. Although both sunlight and X-rays are in Group 1, X-rays are clearly more capable of triggering cancer than sunlight. But exposure matters. A single chest X-ray is not a problem but repeated baking in the sun is. More photons of lower energy can have a greater effect than fewer photons of greater energy. Then there is individual liability. A person with dark skin is less at risk for developing cancer than someone with pale skin even at the same ultraviolet light exposure. Inhaled sand is also listed in Group 1. That’s because studies have shown that workers engaged in occupations that can result in inhaling sand show a significantly increased risk of cancer. But this doesn’t mean that going to the beach and frolicking in the sand is a risky business. Tobacco smoke is also in Group 1because there is no doubt that it causes lung cancer. In fact about ninety percent of all lung cancer cases can be attributed to smoking. Alcohol is also in this category because it is known to increase the risk of oral cancers as well as breast cancer, yet nobody worries about drinking a glass of wine. Listing processed meat in IARC’s Group 1 just says that like alcohol, like tobacco, like sunshine, and some 180 other chemicals, mixtures and exposure circumstances, it is capable of causing cancer. It does not mean that if you have a bacon lettuce and tomato sandwich you are putting yourself at risk. Let’s clarify what is meant by processed meat. Grinding meat into hamburger does not result in processed meat. But smoking, fermenting or adding chemicals such as salt or nitrites to either extend the product’s shelf life or change its taste does. We’re talking about bacon, sausages, hot dogs, salami, corned beef, beef jerky and ham as well as canned meat and often meat-based sauces. The evidence that these tasty morsels are linked to cancer comes from observational studies, which of course do not prove cause and effect. But they are quite consistent in demonstrating that populations that consume lots of processed meats have higher cancer rates, particularly colorectal cancer, even when corrections are made for smoking, other foods eaten and activity levels. Furthermore, there are theoretical and experimental foundations for declaring some components found in processed meat, like polycyclic aromatics, heterocyclic amines, nitrites, insulin-like growth factor and heme-iron, carcinogenic. The evidence is certainly not ironclad, but science rarely is. It comes down to making educated guesses and evaluating the downside of such guesses. There is no significant downside to limiting processed meat, especially if it is replaced by plant products.But the significant question to ask is how much can we reduce our risk of colorectal cancer by robbing our taste buds of the taste of bacon and such? The risk of this cancer in the general population is roughly six in a hundred. After poring through some 800 peer-reviewed publications, IARC estimates that eating 50 grams of processed meat every day over a lifetime increases risk by about 18%. In other words, if a hundred people follow such a regimen over a lifetime, there will be seven cases of colorectal cancer instead of six. So for an individual, the chance of getting colon cancer because of eating processed meats is about 1 in 100. That is a very small risk, but because there may well be millions of people following such a diet, the impact on the population can be significant, in IARC’s estimate, about 34,000 cases a year.

What do we do with this information? A one in a hundred chance is not insignificant and it makes sense to try to reduce it. That means consuming less than 50 grams of processed meat a day on average. To do that we need to keep some numbers in mind. Two to three strips of bacon add up to 50 grams, as do two slices of ham, 4 slices of salami or one hot dog. Remember though that we are talking averages here. Certainly a couple of hot dogs, a salami sandwich and a couple of bacon and egg breakfasts a week is not a great risk. But if you have a smoked meat sandwich, well, you have used up your weekly allotment. But remember that all these numbers are estimates, basically educated guesses, and are not based on hard evidence.

Read more

“No day shall erase you from the memory of time”

Our OSS Blog - Tue, 11/24/2015 - 14:35

The city that never sleeps; where dreams are made and realized, (and probably more often than not, discarded); the possibilities endless. I was strolling through the streets and making my way down to the Financial District where I was set to have a tour of the 9/11 Museum.

The day, I was soon told by our guide, was similar to that horrific September 11th morning – where, according to air traffic control, skies were an “extreme clear” – where in a matter of minutes, the world, as we knew it, would change forever. The Museum is relatively new, only opening its doors to the public in 2014. And although I Iived in NYC last year, I never ended up making my way to the museum. I knew there were two pools, where each of the towers stood, but that was about it. Of course I also knew there was much consultation with the families of the victims as to what the museum should include and how its artifacts presented. With whatever unknown I went in with, I did know that I would feel much of the same emotions I felt on that Tuesday September morning where, in Mr. Moore’s English class, we were told that a plane had crashed into the World Trade Center. Read more

Chemistry Lesson for Food Babe #5

Our OSS Blog - Tue, 11/17/2015 - 19:18

Just about everyone now knows something about DNA ( with some obvious notable exceptions). The term “template of life” has been repeatedly used in the press to describe this molecule. That is quite accurate because DNA is like a library of information which tells our cells which proteins to synthesize. Proteins are the key to life because they make up important structures of the body as well as hormones and the enzymes that govern the body’s numerous chemical reactions. DNA is a nucleic acid, a "polymer" composed of pieces called nucleotides strung together like beads on a necklace.

Each of these nucleotides is made up of a sugar called deoxyribose, a phosphate group and a molecule commonly referred to as a “base.” It is the sequence of the bases along the nucleic acid chain that holds genetic information. There are four such bases: adenine, thymine, cytosine and guanine. They are named after the source from which they were isolated. Adenine from the Greek word for gland because it was first isolated from the pancreas, thymine from the thymus, cytosine from cells and guanine from bird guano, the technical name for bird poop.

Yes Ms. Hari, every one of your cells contains the same chemical that is found in bird excrement. This is as relevant as finding azodicarbonamide, the chemical that was used in Subway rolls in yoga mats. (I'm including the molecular structures of the four nucleotides although I'm quite confident they will be meaningless to our intended pupil. I have no idea what she thinks of molecular structures, but given that she thinks that multisyllabic names make a chemical dangerous, she probably doesn't look on them favourably.)

Read more

Food Babe Lesson #4

Our OSS Blog - Tue, 11/17/2015 - 19:15

Rotting apples release ethylene gas, which is a natural hormone produced by fruits to stimulate ripening. A rotten apple is just an overly ripe apple, producing enough ethylene to "ripen" the rest of the apples in the barrel. The process is usually initiated by physical damage to an apple. The skin becomes bruised, releasing nutritious juice which is very inviting to air-borne molds. When molds set up shop on the apple, ethylene production increases, ripening other apples, inviting more mold! The answer of course is to remove the rotten apple!

Although in this instance the reaction is not desirable, the use of ethylene gas often allows fruit to be picked "green" and to be subsequently ripened during transport in tank cars under an atmosphere of ethylene. This is especially useful in the case of bananas, the most widely consumed fresh fruit in North America. Bananas bruise very easily and could not survive shipping if they were picked when ripe. Green bananas are much more hearty and stand up well during transport. If they are still green when purchased you can ripen the bananas by putting them in a plastic bag with an over-ripe apple!

Our such bases: adenine, thymine, cytosine and guanine. They are named after the source from which they were isolated. Adenine from the Greek word for gland because it was first isolated from the pancreas, thymine from the thymus, cytosine from cells and guanine from bird guano, the technical name for bird poop.

Yes Ms. Hari, every one of your cells contains the same chemical that is found in bird excrement. This is as relevant as finding azodicarbonamide, the chemical that was used in Subway rolls in yoga mats. (I'm including the molecular structures of the four nucleotides although I'm quite confident they will be meaningless to our intended pupil. I have no idea what she thinks of molecular structures, but given that she thinks that multisyllabic names make a chemical dangerous, she probably doesn't look on them favourably.)

P.S. Vani's take on this would likely be: Do you want a chemical that is used to make pig balls in your bananas?

(Ethylene is used to make polyethylene which is used to make "pig balls" that are thrown into pig pens to give the animals something to play with instead of nibbling on each others' ears and tails.)

Read more

Cleaning the air with jeans

Our OSS Blog - Tue, 11/17/2015 - 19:02
You may want them in your jeans, but you probably want to keep them away from your genes. They’re “nano” particles of titanium dioxide, about ten billionths of a meter in diameter that can exhibit beneficial properties not possessed by their larger cousins, but they may also have a darker side.   There are more jeans in the world than people. That stat sparked an idea in the mind of University of Sheffield chemist Tony Ryan. Why not use people’s penchant for wearing denim to help purify the air? After all, the International Agency for Research on Cancer (IARC) classifies outdoor air pollution in Group 1, reserved for substances that are known to cause cancer in humans. It estimates that there are up to seven million premature deaths in the world every year as a result of air pollution.   With thoughts of reducing pollutants such as the nitrogen oxides and volatile organic compounds emitted by vehicles, power plants, residential heating, cooking and various consumer products, Ryan, in partnership with former fashion designer Helen Storey, came up with the concept of “Catalytic Clothing.”   “Catalytic” apparel uses fabric impregnated with nano-sized particles of titanium dioxide to degrade air pollutants. “Nano” means small. So small that the combined surface area of the nanoparticles that are distributed through any fabric is immense. And that matters because the action takes place on the surface of the particles.   Titanium dioxide is a “photocatalyst,” meaning that it can make chemical reactions happen when exposed to the right wavelength of light, in this case ultraviolet. The light energy causes it to release electrons that then target water molecules in the air, breaking them apart to form extremely reactive hydroxyl radicals that then chop up organic compounds into simple molecules such as carbon dioxide and convert nitrogen oxides into water soluble nitric acid. This is not just theory, it is well established technology that already has commercial application, for example in “self-cleaning glass.” A thin layer of titanium dioxide ends window cleaning worries, as long as the climate provides for sufficient sunshine and rain. The chemical can even be mixed into concrete, resulting in self-cleaning buildings such as the Jubilee Church in Rome.   Thanks to titanium dioxide we may never have to confront yellow urinals again. Coating the ceramic with a layer of titanium dioxide, about a fiftieth the thickness of human hair, prevents stains from forming. The technology also has potential in operating rooms where bacteria on floor and wall tiles can be destroyed with fluorescent light, common in hospitals, furnishing enough of the right wavelengths. And how about self-cleaning tiles for the kitchen and bathroom?   Clearly, titanium dioxide photocatalysis is sound technology. But can wearing jeans treated with this chemical actually have an impact on air pollution? According to Professor Ryan, yes. He calculates that that if a third of a million people in Sheffield wore such jeans, nitrogen oxide levels could be significantly reduced. And there is no need to buy special jeans. Titanium dioxide particles stick readily to the fabric so the idea is to add a formulation of the chemical to the water when the jeans are being laundered. The nano particles will stick until the fabric degrades.   As is often the case in science, there is a “but.” What happens if nanoparticles enter the bloodstream? What tissues might they affect? Titanium dioxide has the potential to damage DNA, but to do that it has to enter cells. That is a possibility since nanoparticles are smaller than cells. In the lab, nano titanium dioxide has been shown to damage DNA in human intestinal cells, but only at doses far higher than what could ever be ingested.   In any case, people will not be dining on their treated jeans. But they may be gulping donuts, or a vast array of other foods such as Gobstoppers, M&Ms, pastries or soy milk that have titanium dioxide added to them to provide a more pleasing whitened appearance. Only about 5% of the titanium dioxide is made of nano sized particles, but that has raised concern because IARC has classified titanium dioxide as possibly carcinogenic to humans (Group 2B). This classification is based on inhalation of titanium dioxide dust in an occupational setting, quite a different exposure than eating a donut with a titanium dioxide enhanced white sugar coating. Nevertheless consumer activism has resulted in Dunkin Donuts removing titanium dioxide from the powdered sugar coating on its products. Maybe it can be redirected into catalyst jeans. We really don’t need to make junk food look more appealing, do we? Read more

Science & Society : @McGillOSS

@McGillOSS - Mon, 11/16/2015 - 12:07
Bubbly and fizzly and ? Oh my! http://bit.ly/1kAtByU 

Science & Society : @McGillOSS

@McGillOSS - Mon, 11/16/2015 - 10:14
Action figures never looked so scientific. The Body of Evidence explains "peer reviews" using little cute men. http://bit.ly/1MMNRYx 

Jonathan Jarry : @crackedscience

@McGillOSS - Mon, 11/16/2015 - 08:05
VIDEO: How does work in ? Playmobil characters to the rescue! http://ow.ly/UG80R  @McGillOSS @CaulfieldTim @DrLabos

Science & Society : @McGillOSS

@McGillOSS - Sun, 11/15/2015 - 16:00
Thank you, @crackedscience, for coming on today’s show! Check out Bodyofevidence.ca for more debunking & intelligent humour.

Science & Society : @McGillOSS

@McGillOSS - Sun, 11/15/2015 - 15:58
“Half of what u shove in your mouth should be a fruit or a vegetable.” @crackedscience references @CaulfieldTim’s “The Cure for Everything”

Science & Society : @McGillOSS

@McGillOSS - Sun, 11/15/2015 - 15:56
“We don’t heal people. People heal themselves.” The legal loophole used by the

Science & Society : @McGillOSS

@McGillOSS - Sun, 11/15/2015 - 15:41
, & all that bunk. Give Dr. Joe a call and ask away or share your story. 514-790-0800

Science & Society : @McGillOSS

@McGillOSS - Sun, 11/15/2015 - 15:25
If you eat sprouted vegetables, you’re set for life. @crackedscience recounting ’s message on the key to health.

Science & Society : @McGillOSS

@McGillOSS - Sun, 11/15/2015 - 15:21
The Institute. “So much concentrated in one place,” says @Joeschwarcz. now. http://CJAD.com 

Jonathan Jarry : @crackedscience

@McGillOSS - Sun, 11/15/2015 - 15:06
On @CJAD800 w @joeschwarcz right now.

Timothy Caulfield : @CaulfieldTim

@McGillOSS - Sun, 11/15/2015 - 14:32
.@crackedscience @joeschwarcz Perfect team to tackle the Clement bunk! @CJAD800 Onward science!

Science & Society : @McGillOSS

@McGillOSS - Sun, 11/15/2015 - 12:10
Jonathan Jarry & Dr. Joe chat about the saga 3pm ET. Some background info: http://bit.ly/1iZCW1G 

Science & Society : @McGillOSS

@McGillOSS - Fri, 11/13/2015 - 15:58
Now that's a shame. http://cnn.it/1kuMALc 

Science & Society : @McGillOSS

@McGillOSS - Fri, 11/13/2015 - 14:20
and supplements are touted as . But what if too much of a good thing is bad? @cbcfifth 9pm ET w @DrPaulOffit


Stay Connected with the OSS

Like us on FacebookLike us on Facebook