Plastics: A Close Look

CF000313 18x24
Albatross at Midway Atoll Refuge by U.S. Fish and Wildlife Service Headquarters

There’s irony in having small bits of floatable plastic debris and larger chunks of trash in our oceans. Millions of years ago, many of the hydrogen and carbon atoms within these man-made polymers were part of marine life. Death, deposition and pressure simplified the organic molecules of the dead. Then a species that indirectly evolved from these oceanic ancestors accidentally stumbled upon a crude liquid. Eventually they learned to use not only its energy content but its building blocks. Some of these were linked into molecular chains that could be molded into any shape. But these chains proved to be resistant to the usual degradative action of bacteria and fungi. Coupled with one-time use, over-consumption and poor recycling, we have a problem on our hands as the plastic in oceans severely impacts wildlife.oil Natural Gas Formation lines only-L

We all curse plastic when it breaks and worry about its other drawbacks, which are amplified by human behaviour. But they do limit our use of other resources such as wood and metal.  Plastics chemists discovered the catalysts that made plastics more affordable and kept devising recipes in order to suit practical needs like placing side chains with hydroxyl groups on a contact lens polymer that could attract enough water to lubricate the eyes.

Yet perhaps because of the negative connotations of plastic, even chemistry professors writing organic chemistry textbooks for freshmen avoid the topic. The classic and otherwise excellent Organic Chemistry by Morrison and Boyd published between the late 1950’s and 70’s devoted only 8 of its 1183 pages to plastic. One could argue that the basics have to be covered adequately before one can understand how high temperatures can induce petroleum’s larger molecules to become free radicals, which with rapid cooling, convert into small, unsaturated hydrocarbons. One of those products, ethylene, is then polymerized into polyethylene which is used in wraps, squeeze bottles, disposable gloves, garbage bags and to weld cracks in kayaks.

But relative to how much space three recent popular organic chemistry textbooks devote to plastic, Morrison and Boyd wrote a thesis. And yet while sitting on a chair cushioned by polyurethane, I look around me and notice the acrylo-nitrile-butadiene-styrene(ABS)on my keyboard and mouse, two polyester backpacks on the floor and a polypropylene pot under my avocado tree. Students should learn how such ubiquitous substances are synthesized, and that they have different tensile strengths and varying resistance to substances like alcohols. And they should learn about the carbon footprint involved in producing such large quantities and the consequences of not recycling most of them.

On the internet there are still people worrying about bisphenol A (BPA) leaching out of plastic pots and getting into their herbs and marijuana. For starters, the production of plant pots does not use BPAs. The latter is associated with polycarbonate plastic found in DVDs , plastic helmets and other hard plastic products., some of which are labeled as code 7. In 2008, Health Canada banned BPA from plastic baby bottles and luckily the European Union followed suit as a precaution. The former also reassessed dietary exposure to the chemical and found that it was lower than what was previously estimated. They concluded that exposure to BPA through food packaging is not expected to pose a health risk to the general population, including newborns and young children. Other regulatory agencies in the United States, the European Union and Japan agreed with their analysis. The average exposure was 0.055 micrograms per kilogram of body weight per day. Not all concerns regarding BPA can be dismissed. Fish seem to be the most BPA-sensitive organisms.Plastic-Resin-Codes-584x1024 Depending on whose guidelines one examines, the predicted no-effect concentrations in freshwater range from 0.175 to 1.7 nanograms per milliliter or parts per billion(ppb). We also need more studies that look at the combined effect of various low level endocrine disruptors and other toxins in the environment.

While China’s economy has mushroomed in the last two decades, its short-lived plastic exports have found their way into the world’s still largest economy, the United States. At the same time, we’ve had computer, electronic game and phone revolutions, all of which have fed an exponential growth in the amount of plastic found in municipal waste. The only plastics that can be recycled economically so far, and in part only because China buys most of the refuse, are high density polyethylene(HDPE), polyethylene terephthalate (PET) and polystyrene. (recently China has refused some of Canada’s used plastic because of contamination.) Milk jugs are made of HDPE and PET is found in ziploc food storage bags, disposable water bottles, soft drink bottles and recently, vegetable packaging. The latter used to be code 6(polystyrene), which shrinks in the microwave when heated and is not as easily recycled.  in 2011, only 31% to 44% of Canadian homes had access to centres that could handle polystyrene, depending on the variety of that specific plastic.Graph-680x453

Although more recycling can be done—the recycling rates for those two materials in the U.S. are only in the 30% zone—people have not warmed up to the 3 R’s“reduce” option. At least in theory, we could buy less plastic stuff when possible and drink tap water. To avoid plastic cups and cutlery at parties, spike the punch and get the guests to do the dishes. *
Such an approach does not have to negatively impact the economy. Money can be spent on non-plastic products and services and on paying down debt, which in the long run increases purchasing power.

plasticMoneyThe idea of biodegradable plastics is appealing. If they are produced on a global scale, however, there could be undesirable effects, especially if the raw materials are grown on land and not extracted from algae. The land needed for additional biomass could lead to deforestation, and then subsequent growth of crops won’t compensate for CO2 released by decomposing trees and biodegradable plastic. One thing about conventional plastic: when not incinerated but kept in the home or in landfills, it does, at least for a century, keep petroleum’s carbon away from the atmosphere. And no one will throw away Canadian plastic $20s.

plastic
People often forget that we pay for packaging. If it’s good enough for stores to keep things visible and organized, why not do likewise?

* In the sixties throughout the 1980’s, a party with any combination of my 14 aunts was guaranteed to be free of plastic utensils.  After cooking a mind-blowing meal for 30 people, they were happy to chat among themselves and wash dishes faster and better than the average machine while the men played Italian card games —another activity with a low environmental impact :)—–the un-division of labour was terribly sexist, mind you!)

Sciences In the Mural Of Life

Created Nov 8 2012 – 1:00 AM Revised Aug 19, 2014 and April 20, 2018

There’s irony in having small bits of floatable plastic debris and larger chunks of trash in our oceans. Millions of years ago, many of the hydrogen and carbon atoms within these man-made polymers were part of marine life. Death, deposition and pressure simplified the organic molecules of the dead. Then a species that indirectly evolved from these oceanic ancestors accidentally stumbled upon a crude liquid. Eventually they learned to use not only its energy content but its building blocks. Some of these were linked into molecular chains that could be molded into any shape. But these chains proved to be resistant to the usual degradative action of bacteria and fungi. Coupled with one-time use, overconsumption and poor recycling, we have a problem on our hands as the plastic in oceans severely impacts wildlife.oil-Natural-Gas-Formation-L

We all curse plastic when…

View original post 946 more words

Plastics: A Close Look

Created Nov 8 2012 – 1:00 AM Revised Aug 19, 2014 and April 20, 2018

CF000313 18x24
Albatross at Midway Atoll Refuge by U.S. Fish and Wildlife Service Headquarters

There’s irony in having small bits of floatable plastic debris and larger chunks of trash in our oceans. Millions of years ago, many of the hydrogen and carbon atoms within these man-made polymers were part of marine life. Death, deposition and pressure simplified the organic molecules of the dead. Then a species that indirectly evolved from these oceanic ancestors accidentally stumbled upon a crude liquid. Eventually they learned to use not only its energy content but its building blocks. Some of these were linked into molecular chains that could be molded into any shape. But these chains proved to be resistant to the usual degradative action of bacteria and fungi. Coupled with one-time use, over-consumption and poor recycling, we have a problem on our hands as the plastic in oceans severely impacts wildlife.oil Natural Gas Formation lines only-L

We all curse plastic when it breaks and worry about its other drawbacks, which are amplified by human behaviour. But they do limit our use of other resources such as wood and metal.  Plastics chemists discovered the catalysts that made plastics more affordable and kept devising recipes in order to suit practical needs like placing side chains with hydroxyl groups on a contact lens polymer that could attract enough water to lubricate the eyes.

Yet perhaps because of the negative connotations of plastic, even chemistry professors writing organic chemistry textbooks for freshmen avoid the topic. The classic and otherwise excellent Organic Chemistry by Morrison and Boyd published between the late 1950’s and 70’s devoted only 8 of its 1183 pages to plastic. One could argue that the basics have to be covered adequately before one can understand how high temperatures can induce petroleum’s larger molecules to become free radicals, which with rapid cooling, convert into small, unsaturated hydrocarbons. One of those products, ethylene, is then polymerized into polyethylene which is used in wraps, squeeze bottles, disposable gloves, garbage bags and to weld cracks in kayaks.

But relative to how much space three recent popular organic chemistry textbooks devote to plastic, Morrison and Boyd wrote a thesis. And yet while sitting on a chair cushioned by polyurethane, I look around me and notice the acrylo-nitrile-butadiene-styrene(ABS)on my keyboard and mouse, two polyester backpacks on the floor and a polypropylene pot under my avocado tree. Students should learn how such ubiquitous substances are synthesized, and that they have different tensile strengths and varying resistance to substances like alcohols. And they should learn about the carbon footprint involved in producing such large quantities and the consequences of not recycling most of them.

On the internet there are still people worrying about bisphenol A (BPA) leaching out of plastic pots and getting into their herbs and marijuana. For starters, the production of plant pots does not use BPAs. The latter is associated with polycarbonate plastic found in DVDs , plastic helmets and other hard plastic products., some of which are labeled as code 7. In 2008, Health Canada banned BPA from plastic baby bottles and luckily the European Union followed suit as a precaution. The former also reassessed dietary exposure to the chemical and found that it was lower than what was previously estimated. They concluded that exposure to BPA through food packaging is not expected to pose a health risk to the general population, including newborns and young children. Other regulatory agencies in the United States, the European Union and Japan agreed with their analysis. The average exposure was 0.055 micrograms per kilogram of body weight per day. Not all concerns regarding BPA can be dismissed. Fish seem to be the most BPA-sensitive organisms.Plastic-Resin-Codes-584x1024 Depending on whose guidelines one examines, the predicted no-effect concentrations in freshwater range from 0.175 to 1.7 nanograms per milliliter or parts per billion(ppb). We also need more studies that look at the combined effect of various low level endocrine disruptors and other toxins in the environment.

While China’s economy has mushroomed in the last two decades, its short-lived plastic exports have found their way into the world’s still largest economy, the United States. At the same time, we’ve had computer, electronic game and phone revolutions, all of which have fed an exponential growth in the amount of plastic found in municipal waste. The only plastics that can be recycled economically so far, and in part only because China buys most of the refuse, are high density polyethylene(HDPE), polyethylene terephthalate (PET) and polystyrene. (recently China has refused some of Canada’s used plastic because of contamination.) Milk jugs are made of HDPE and PET is found in ziploc food storage bags, disposable water bottles, soft drink bottles and recently, vegetable packaging. The latter used to be code 6(polystyrene), which shrinks in the microwave when heated and is not as easily recycled.  in 2011, only 31% to 44% of Canadian homes had access to centres that could handle polystyrene, depending on the variety of that specific plastic.Graph-680x453

Although more recycling can be done—the recycling rates for those two materials in the U.S. are only in the 30% zone—people have not warmed up to the 3 R’s“reduce” option. At least in theory, we could buy less plastic stuff when possible and drink tap water. To avoid plastic cups and cutlery at parties, spike the punch and get the guests to do the dishes. *
Such an approach does not have to negatively impact the economy. Money can be spent on non-plastic products and services and on paying down debt, which in the long run increases purchasing power.

plasticMoneyThe idea of biodegradable plastics is appealing. If they are produced on a global scale, however, there could be undesirable effects, especially if the raw materials are grown on land and not extracted from algae. The land needed for additional biomass could lead to deforestation, and then subsequent growth of crops won’t compensate for CO2 released by decomposing trees and biodegradable plastic. One thing about conventional plastic: when not incinerated but kept in the home or in landfills, it does, at least for a century, keep petroleum’s carbon away from the atmosphere. And no one will throw away Canadian plastic $20s.

plastic* In the sixties throughout the 1980’s, a party with any combination of my 14 aunts was guaranteed to be free of plastic utensils.  After cooking a mind-blowing meal for 30 people, they were happy to chat among themselves and wash dishes faster and better than the average machine while the men played Italian card games —another activity with a low environmental impact :)—–how terribly sexist!)
People often forget that we pay for packaging. If it’s good enough for stores to keep things visible and organized, why not do likewise?

Nitrite In The Hot Dogs Of My Youth

Rewritten: November 2014 I had filtered the tone and content of the original piece written in 2011 for fear that it would be shot down on a conservative website that once hosted my blogs. But I’ve decided to reveal the rest of the story.

nitritesI hope that Health and Welfare Canada guidelines for certain additives are a bit more stringent than they have to be to help compensate for possible loose play on the part of industries. When I was a student and shortly after I graduated, I analyzed fat content, dextrose and nitrite levels in hot dogs and other meat products for a well-known company. I’m not naming the company because for all I know they may have mended their ways. Also, I never gathered evidence that the whole industry was or is guilty of the things that I witnessed.

Nitrite (NO2) is added in small quantities to preserve and to color many cold cuts and hot dogs. At the time, acceptable limits for NO2 ranged for 100 to 150 ppm (mg of nitrite per kg of meat), depending on the product. But levels frequently surpassed the guidelines by 25 to 50%. At first I questioned my own analyses, but they were confirmed by my supervisor. The head of the lab said he would look into it at the production end, but weeks later the problem persisted. In general we were instructed not to carry out the analyses in duplicate, unless an anomalous result surfaced.

We had learned in the statistical math section of analytical chemistry that tests of the sort should be carried out in triplicate. One day an inspector from Health and Welfare Canada came into the lab, and I told him about the problem. He told me he was just a summer replacement with only a background in CEGEP ( a junior college) health sciences, and so that he could not really understand what I was saying. Later that summer, I was switched to the night shift, and I was alone in the lab. Digging into records from the previous two years, I found that other technicians had also been routinely finding high levels of nitrite (exceeding guidelines) in two specific products.

Nitrite, I realize, is an important preservative, and although it has been associated with cancer in rats, the “traditional” consensus is that the possibility of a similar occurrence in humans is only slightly elevated because of the concurrent addition of erythorbate and/or ascorbic acid. This prevents the formation of nitrosamines in the stomach’s acidic environment, the actual compounds with carcinogenic connections in animals. But I also saw the pale color of the hot dog mixture prior to nitrite addition, and it would not have been so pale if the ingredients weren’t such a mishmash of intestines and other meat “scraps”.

hotdogs_insideMost of the public was unaware that what they were really tasting in hot dogs were the strong spices, salt and sugars. Our analyses revealed that the fraction of dextrose in hot dogs ( close to 10%)  was routinely greater than that of protein, placing the product somewhere on the spectrum between meat and candy. (Currently, according to USDA analyses, things are better from that perspective. The ratio of protein to sugar in a 100 gram sample ranges from 6 to 10 grams of protein to 1 gram of sugar. Yet fresh meat or fish has triple the amount of protein.) Their ham was also adulterated with water, which then facilitated the growth of bacteria, thus increasing the need for nitrite additives. Even today processed ham is still diluted, slicing the protein level to half of what it should be.

When working there, I was strongly tempted to become a whistle-blower and to go public with what I thought were outrageous company practices from both a health and scientific standpoint. But relatives and friends were not supportive, and I was too wimpy to act alone. Aside from writing this piece, I have told my story to hundreds of students in my career, and since those analyses, I don’t think I’ve eaten more than a couple of meat-hot dogs in the last three decades.

A Journal of the National Cancer Institute study in 2005 found a link between processed meats and pancreatic cancer, but in fairness,the study did not prove that the risk was to the presence of nitrites. In recent years, Maple Leaf has used celery extract, which is rich in nitrites as a way of deceiving consumers into thinking they are buying a healthy alternative.

Defenders of nitrite in processed meats like to point out that lettuce and spinach can also have elevated levels of nitrate (which can be converted in to nitrite). There are two problems with their argument:

(1) Not all samples have concentrations comparable to nitrite levels. If the lettuce and spinach is not grown with fresh manure or with synthetic fertilizer, the nitrate levels plummet.

(2) The argument is akin to the nuclear industry’s old trick of attempting to abate fears about radiation wastes by pointing out that there are already natural radioactive isotopes in the earth’s crust and in our bodies. In both cases, what they are hiding is that by artificially increasing the background concentrations they are increasing the risk of complications.

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