[MUSIC] Hello. We're going to talk about chemicals in cigarettes today. It's hard to believe that we still need to talk about this topic many years after we've known that the chemicals in cigarettes are harmful. And I'm going to tell you today that there's no such thing as safe tobacco. Some of the harmful chemicals found in tobacco occur naturally in the plant. Others are absorbed from the soil and fertilizers. Some dangerous chemicals are formed when the tobacco is processed, when the cigarettes are manufactured. And when the cigarette burns, new chemicals are created. My name is Joanna Cohen. I'm a faculty member here at the Bloomberg School of Public Health. And I'm director of the Institute for Global Tobacco Control. Over the next few minutes, we're going to talk about the chemicals that we can find in cigarettes and cigarette smoke. I'm going to tell you a story about the fraud of low-tar cigarettes. And we'll touch on the additives and flavorings in tobacco products. Cigarette smoke is a complex mixture of over 7,000 chemicals. And at least 69 of them are cancer-causing, what we call carcinogens. Many of these chemicals that we find in tobacco products are also found in consumer products, but these products have warning labels on them. They warn us about the danger of the poisons in these products. But there's no such warning about the toxins in tobacco smoke. So let me first mention three classes of chemicals that can be found in tobacco smoke. We have carcinogens or cancer-causing chemicals. I've said that there are at least 69 of them, and let me tell you about just a few. We have Formaldehyde, which is used to embalm dead bodies. You can find Benzine, which is found in gasoline. Polonium 210 is radioactive and very toxic, and Vinyl Chloride is used to make pipes. Not the tobacco kind, but pipes in the ground [LAUGH]. And there are also toxic metals. Chromium can be found in steel. Arsenic is used in pesticides. Lead, we know is harmful as used in paints and other materials. And then Cadmium is found in batteries. And there are also lots of poisonous gasses. Carbon Monoxide for example as you know, is found in car exhaust. Hydrogen Cyanide is used in chemical weapons. Ammonia is found in household cleaners. Butane is used in lighter fluid. And Toluene is found in paint thinners. And there are over 500 additives that have been documented to be contained in cigarettes, which we'll describe shortly. Cigarette smokers are exposed to thousands of chemicals in the cigarette smoke. And the amount of exposure and the dose are influenced on how the products are smoked. So, for example, if you take more puffs on your cigarettes, if you inhale more deeply. And I'll tell you later that if you block the ventilation holes on low-tar cigarettes, you're going to be exposed to more of the smoke and more of the chemicals. And there are also additives in tobacco products, particularly in cigarettes, that can help deliver higher doses of nicotine. For example, Ammonia is used in cigarettes to alter the pH of tobacco smoke. And that increases the level of nicotine that a smoker gets. Sort of like freebasing. So, the tobacco companies are very good at controlling the amount of nicotine that's delivered to the smoker because that's why people smoke, the addictive products of nicotine. There are also other chemical constituents like Theobromine that's found in cocoa. And Glycyrrhizin that's found in licorice that expand the alveoli of the lungs and thereby increase the surface area for absorption of the chemicals found in smoke. Cigarettes are engineered to deliver high doses of nicotine. And one of the things that tobacco companies do is alter the pH of tobacco smoke using additives such as Ammonia. And by including Ammonia in the product, it increases the level of nicotine delivered in cigarette smoke. And this is really important because people continue to smoke because of the nicotine and its addictive properties. There are also other constituents in cigarettes such as Theobromine and others that expand the alveoli of the lungs. And thereby, it increases the surface area for absorption of the chemicals found in smoke. And you don't only find these chemicals in cigarettes but in other tobacco products such as cigars, cigarillos, roll your own tobacco, and water pipes, which are also known as shisha, hookah, or nargiyl. This slide shows some of the health effects caused by smoking. And this is a figure that was in the 2014, the 50th Anniversary Issue of the U.S. Surgeon General's Report on Smoking and Health. And it shows some of the cancers that are caused by smoking on the left hand side and other chronic diseases caused by smoking on the right hand side of the body. And the conditions in red are the ones that were newly found to be causal in the 2014 Surgeon General's Report. So when smoke is inhaled from the burning cigarette, it causes changes to our cells. And the chemicals from the smoke get into our bloodstream and are transported to the liver where they under go bio-transformation. Our liver enzymes can transform these chemicals into more harmful and lethal forms. So for example the PAHs or Poly-Aromatic Hydrocarbons in cigarette smoke undergo chemical transformation within the body to carcinogenic metabolites. And so some of the immediate effects of the chemicals in cigarette smoke, they've influenced the contraction of the smooth muscle of the walls of the airways. So that results in impeding the flow of air into your lungs. They also influence the contraction of blood vessels and decrease blood flow. And eventually these processes can result in both local and systemic diseases. So when the chemicals present in smoke diffuse through our bloodstream, they damage our DNA. They can disrupt our hormone processes, they influence the oxidative stress and inflammation as well. And various diseases and cancers result from these complex interactions and processes. So for example, with respect to cancer, tobacco-specific nitrosamines can act as tumor promoters or tumor initiators. And I already mentioned PAH, poly-aromatic hydrocarbons cause genetic mutations in P50, a tumor suppressor gene that protects the body against cancer. So in addition to cancer, tobacco smoke causes lung diseases such as emphysema, chronic bronchitis. It exacerbates asthma and even influences tuberculosis. There are also cardiovascular diseases caused by tobacco smoke including strokes, coronary heart disease. There are unhealthy reproductive outcomes. And, our immune function is diminished from tobacco smoke including longer wound-healing times which is important when you are recovering from surgeries and other types of wounds. And we've also learned that tobacco smoke causes diabetes and arthritis. So, I told you about the chemicals in tobacco smoke and the diseases that they cause. And the main thing that we find in tobacco smoke is tar. Tar is what's harmful, it's the particulate matter of the smoke. And so if we know that tar is harmful, you would conclude that less tar in a cigarette should be less bad, right? Well, that's not exactly the case, and that's part of the low-tar fraud that tobacco companies made us try and believe a number of years ago. So here on the slide we have two ads. One is from the Lorillard Company that made True cigarettes. It's from the 1970s, and there's a tennis player's, it's hard to see. She's smoking a cigarette, taking a tennis break. And she says, considering all I'd heard, I decided to either quit or smoke True. I smoke True. And on the right, we see an ad from Carlton, which is the American tobacco company. And here again, it plays into our belief at the time that less tar is better. So here's a quote saying, I switched to less tar. And some of the fine print says, like many other smokers, I wanted less tar. So what was happening at this time is that the Surgeon General was saying that tars in the cigarette smoke is bad. And that tobacco companies try to prevent people from quitting by giving them an option of low-tar cigarettes. So you don't have to quit now, you can smoke a low-tar cigarette and do something for your health. The way that the tar in cigarettes is measured is through a standardized smoking machine developed by the Federal Trade Commission or FTC. And the cigarette smoking machine takes a certain number of puffs of a certain volume, at a certain frequency. And collects the tar on a filter and measures the amount of tar. And that's how tobacco companies were reporting the tar levels in cigarettes. The problem is that people don't smoke like machines. And what the companies did to get lower tar readings on these smoking machines was to put little ventilation holes in the filter. And on the top right, it's a bit hard to see, but it shows the filter paper with some small holes in it. Those were the ventilation holes. So when the smoking machine inhaled, air would come through those holes, dilute the smoke, and the smoking machines would record lower tar measures. As I said, people don't smoke like machines. And what people would do. Because, people, when they smoke, their brain knows how much nicotine it wants [LAUGH] and it needs to get. So, people realize when they smoke, they needed to get, you know, more of the nicotine from the cigarette. So smokers had compensatory behaviors such as taking more puffs from those cigarettes, inhaling more deeply. And also covering the ventilation holes with either their lips or their fingers to prevent the dilution of the smoke and get the full level of nicotine that their brains wanted. So the fact that when smokers smoke low-tar cigarettes, they inhale more deeply to get the nicotine they need from their so-called low-tar cigarettes. What we see is that the squamous-cell carcinoma, which is found in the tissues of the upper respiratory tract. And that's the main kind of lung cancer that we've found you know, 30 years ago, has now switched to adenocarcinoma, which is found deeper in the lung tissue. Deeper in the lung, and it's much harder to treat too. And that's because smokers are inhaling more deeply and getting the smoke all the way to the bottom of their lungs so they can get the nicotine hit that they need. So, just because it says low-tar and it's low tar from the smoking machine, doesn't mean that the smoker's getting less tar. They can actually get much more tar than a regular cigarette, just depending on how you smoke it. The exposures and the effects from low tar cigarettes are exactly the same as from regular cigarettes because the tobacco and the smoke is exactly the same. So, again, the chemicals that you'll get from these types of cigarettes are influenced by how deeply you inhale, the frequency that you inhale. And as well, the extent to which the filter vents are blocked, either by your lips or by your fingers. And again, the health effects are found through out the body. There are both acute and long term negative health effects from regular cigarettes. And from so-called low-tar cigarettes. Once we learned [LAUGH] about the fraud of low tar cigarettes, countries have tried to do things about it. And here in the United States, we have the Family Smoking Prevention and Tobacco Control Act that came into effect in 2009. And among many other things, this law prohibits the sale of cigarettes with, what we call, misleading descriptors, such as low-tar, light, mild, ultra light, et cetera. Anything that reflects the tar content, because now we know it makes absolutely no difference and actually may make things worse. So other countries in the world also prohibit these descriptors such as low tar, light, and mild. Canada, Mexico, Brazil. The whole European union, actually, bans the use of packaging that includes low tar and light. And even pictures or other types of signs that may lead the consumers into believing that some products are less harmful than others. The image on the left shows an example of an education campaign that tries to explain low-tar cigarettes are no different than regular cigarettes. So, well, it actually doesn't show the difference, it shows that regular is equal to light with respect to tar, nicotine, other ingredients, and the risk of lung cancer. And on the right, we see an ad for Marlboro that tells us about the removal of low-tar descriptors from the cigarette. And they want to, once again, just reassure their customers. So they say, your pack may be changing, but your cigarette stays the same. So now what the companies are doing instead of using words or descriptors such as low tar, or light, or mild. They're using colors, as you can see here, or numbers, to still try to denote relative strength of tobacco products. Because if people can think that they can do something that's better for their health by smoking potentially what they might think is a safer cigarette, they will not quit. And that's the problem with the low-tar cigarettes. So in my remaining few minutes, I just want to touch on the idea of flavors of tobacco products. This is an image of products from Kool, which is a Brown and Williamson product. And we can see such wonderful flavors such as Mocha Taboo, Caribbean Chill, Mintrigue, and Midnight Berry. Now, tobacco products are marketed in various flavors partly to reach a particular demography. And we know that it's young people in particular who are attracted to these kinds of flavors. And it can also encourage non-users to experiment with tobacco. because this now just seems like another type of chewing gum, or beverage that youth might try. Examples of flavors in tobacco products, we can find, you know, cherry, strawberry, peach, grape, vanilla in cigarettes and little cigars. Hookah tobacco, or water-pipe tobacco also comes in many flavors, including mint, chocolate chill, white peach, white gummy bear and even blueberry muffin. And now, e-cigarettes are also available in a range of flavors. So for example Blue e-cigarettes have Magnificent Menthol, Cherry Crush, Vivid Vanilla and Java Jolt among others. Now, in the United States, these types of characterizing flavors are no longer permitted in cigarettes, except for the characterizing flavor of menthol which is still allowed. But all these other types of berry, chocolate, alcohol flavorings, are not allowed in cigarettes. But they are still allowed in little cigars and cigarillos, water-pipe tobacco, and e-cigarettes. So flavors do have impacts on your exposure and dose of chemicals. So for example, these types of characterizing flavors can mask the harsh taste of tobacco. They can make is easier to inhale, and they're particularly attractive to youth, as I mentioned. And sometimes, these products are considered starter products. So it's an easier product to inhale and then a smoker can move on to the stronger products. So again, just like low-tar cigarettes, flavored cigarettes or tobacco products have the exact same biological and health effects as non-flavored products. And the director of the CDC, Tom Frieden, said that flavored or not, cigars cause cancer, heart disease, lung disease, and many other health problems. And this is true for all flavored tobacco products. So not only do flavored tobacco products and so-called low-tar products cause similar biological and health effects as full flavored tobacco products. But they actually may pose additional risk because the flavors, in this case, mask the harshness of the taste of tobacco products. And can encourage continued use. So I've really enjoyed talking with you about the chemicals in cigarettes. I think you may have already been aware of some of the issues around flavored tobacco products and low-tar tobacco products. But I hope that I've given you some additional information that these chemicals in cigarettes and tobacco products do not reduce the negative health impacts of these products. And actually may do more to increase the biological and health effects. Because they encourage use, they discourage quitting. And they encourage youth from starting the habit. So, thank you for listening and I hope you enjoy the rest of the class. [MUSIC]
