3rd Govember 2019
by Bruce Krawisz, M.D. : Marshfield Medical Research Foundation
Plastics benefit people in many different ways. Artificial heart valves and the bone cement of artificial joints are made from plastics. Plastic polymers help to make paint, flooring, outdoor siding, tires, clothing, shoes, and parts of cars, computers, and cell phones. Unfortunately, younger people are now inheriting a world diminished by plastic pollution. Plastic is found on the highest mountains, in the depths of the oceans, and in the bodies of whales, fish, sea turtles, and birds. About 90% of Americans, over the age of 6, have the plastic chemical BPA (bisphenol A) in their bodies. Gram for gram, by 2050, there will be more plastic in the oceans than fish. So, why does plastic not degrade naturally and how can people reduce their plastic use in order to reduce plastic blight?
Organic chemicals, derived from petroleum or natural gas, are used to synthesize the many different types of plastic. About 8% of extracted oil goes into plastic production each year. Reducing your plastic use also reduces your dependence on fossil fuels that cause climate destabilization. Both petroleum and plastic consist largely of carbon atoms, bonded to each other and to hydrogen atoms. Carbon atoms form strong covalent chemical bonds. Because a carbon atom can form up to four chemical bonds, it is possible for carbon to make large and complex molecules that are the subject of Organic Chemistry. Carbon-carbon and carbon-hydrogen bonds are unusually strong and stable and so resist degradation by microorganisms. Any plastic thrown away will still be in a landfill or the ocean 500 – 1000 years later. Most of the plastic that has ever been made is still on Earth today. When discarded hard plastic reaches the ocean, it gradually breaks up into small oval or circular pieces that have been called “mermaids’ tears”.
Plastics can be completely degraded by incineration and this process may be used to generate electricity, but the greenhouse gas, carbon dioxide, is then released into the atmosphere. Burning plastic is like burning oil from a global warming perspective. Recently scientists have identified a bacterium Ideonella sakaiensis that can use a particular type of plastic as a food source (Nature Communications https://doi.org/10.1038/s41467-019-09326-3). Possibly, progress in this area of research will permit bacterial recycling of plastic waste someday.
Plastics are synthesized by adding repeat units of a smaller molecule (monomer) together to form a large molecule (polymer). For example, a plastic store bag made of polyethylene consists of the organic molecule ethylene bonded to itself hundreds or thousands of times to form long chains called polyethylene. Similarly, polyvinyl chloride consists of repeat units of the small molecule vinyl chloride and polystyrene is a polymer of the monomer styrene. Plastic monomers are made from oil or natural gas and then converted to plastic polymers. Sadly, large amounts of greenhouse gas emissions result from plastics manufacture and from the required extraction and transportation of fossil fuels to plastics factories.
About 8 billion tons of plastic have been synthesized since 1950. Eight million tons enter the ocean each year. In Los Angeles, United States, 10 tons of plastic, mostly store bags, soda bottles, and straws, enter the ocean each day. Globally half of the plastic is used once and thrown away while only 5-9% is recycled. The average American throws away 185 pounds (84 kilograms) of plastic each year. Americans throw away 35 billion plastic water and soda bottles annually; worldwide 500 billion plastic store bags are used each year. Plastic accounts for about 10% of total waste, but 90% of the waste found in the ocean.
We can reduce our plastic waste, probably not to zero, but substantially nevertheless. Table 1 is a list of suggestions for reducing personal plastic use. This table may not exhaust all ideas and you may think of new approaches. Table 2 contains suggestions for working with others to reduce plastic pollution. Using these tables as a beginning, you may be able to create your own conservation program. Oceanic Global provides information about protecting Earth’s oceans from plastic and may be an idea source:
Plastic production could be significantly reduced and replaced by sustainable alternatives. Ultimately, plastic pollution and greenhouse gas emissions related to plastic manufacturing may be addressed on national and international levels. World governments may wish to end the production of single-use disposable plastic. Oil, gas, and petrochemical infrastructure could be replaced by renewable forms of energy production. Communities could strive to become zero waste producers. Companies that manufacture plastics could become responsible for recycling and cleaning up their plastic waste. The United Nations has compiled standards to help corporations and nations to protect the ocean from pollution. These sustainable standards can be found at:
Of course, all nations need to reduce their greenhouse emissions including those from plastic manufacturing.
When we, individually and collectively, act to reduce plastic use, we are also helping to address the climate crisis.
Ideas for Reducing Personal Use of Plastic
Bring your own shopping bags, backpack, or other reusable containers to stores.
Carry a reusable thermos or water bottle with you (in a backpack or sling)
Carry utensils if you might go to a fast-food restaurant. Avoid single-use plastic.
Use bar soap instead of soap or shampoo from plastic bottles.
Purchase laundry and dish soap in cardboard boxes.
Purchase frozen foods in cardboard boxes.
Purchase food or drink in glass bottles or steel or aluminium cans that can be recycled.
Know your local recycling rules and recycle what you can. Most plastic is not recycled even if collected.
When shopping, examine product choices in order to avoid purchasing plastic containers.
When purchasing clothing, read labels, try to understand what you are buying.
For work or school, consider a reusable lunch box and thermos.
Use digital music sources, rather than CDs or DVDs
Collective Efforts to Reduce Plastic Pollution
Support petitions to store managers or government officials to reduce plastic packaging and pollution.
Consider participating in a beach, neighbourhood, or park cleaning.
Participate in an environmental or political organization. This could be online or in-person.
When you can, vote for leaders who will address pollution and climate destabilization.
Support political or community efforts to reduce production and distribution of single-use plastics.
Inform friends and family about reducing plastic use and other aspects of climate destabilization.
Come back tomorrow to find out about learning to sew.