Plastic Pollution

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Most plastics are carbon-based polymers that are derived from petroleum. They're incredibly versatile—by definition, the word plastic means flexible. They are used mostly for disposable, low-value items such as food-wrap and product packaging, but, there's nothing particularly disposable about most plastics. Scientists estimate that most plastics take a minimum of 450 years  to photodegrade naturally in the environment, which means they breakdown into smaller pieces but stay in the environment, forever—they will not biodegrade. 

Plastic degrades the appearance of our natural landscape, diminishes the capacity of ecosystems to function properly, and silently contributes to species population declines.  

The economic costs of plastic pollution affecting tourism, fisheries and shipping sectors are estimated to be at least $8 billion annually These costs do not consider human health consequences, which are emerging from both the ingestion of plastic in food to the consumption of chemicals leached from single-use plastic containers. Illuminating the vicious cycle of plastic consumption, a recent study found that microplastics are in water, but are over 30 times higher in bottled water.

With respect to the impact of plastic in the oceans, it is estimated that more than 8 million metric tons of plastic enters the oceans each year. In addition, to the 5 trillion pieces of plastic floating in the world’s five ocean gyres, multiples of that amount are estimated to have been deposited on the ocean floor, 1.9 million plastic pieces per square meter to be exact. The Ellen MacArthur Foundation estimates that there will be more plastic than fish in the oceans by 2050 if business is allowed to continue as normal. 

Plastic has an extremely adverse impact on wildlife and marine life. Wildlife was found to ingest plastic as early as 1957 “Plastic debris causes the deaths of more than a million seabirds every year, as well as more than 100,000 marine mammals”. Further, an unknown number of animals become entangled in discarded plastic debris and fishing gear. Ingestion of plastics by marine organisms can hurt or kill them, and may also be acting as a pathway for the transfer of harmful contaminants through food-webs, with biological implications for all life affected.

From a human health perspective, plastic has the potential to leach the chemicals that comprise it into the food and beverages it holds.  The most well-known of these chemicals is bisphenol-A, which was first used as a synthetic estrogen in the 1930s. During the plastic manufacturing process, not all BPA gets locked into chemical bonds; as a result, non-bonded, residual BPA can work itself free, especially when the plastic is heated, whether it’s a baby bottle in the dishwasher, a food container in the microwave, or a test tube being sterilized in an autoclave. Boa et al.(2020) found a relationship between higher BPA ingestion and higher risk for death.  In recent years dozens of scientists around the globe have linked BPA to myriad health effects in rodents: mammary and prostate cancer, genital defects in males, early onset of puberty in females, obesity and even behavior problems such as attention-deficit hyperactivity disorder. Additional research is being conducted with respect to the connection between synthetic estrogens found in plastic and their impact on “the risks of heart attack, obesity and changes in the cardiovascular system”.

Other chemicals in plastic, phthalates are often used as softeners for PVC plastic, to make plastic more flexible. But, phthalates have been found to be harmful to human health. Bis(2-ethylhexyl) phthalate (DEHP), Benzyl butyl phthalate (BBP), Dibutyl phthalate (DBP), and Diisobutyl phthalate (DIBP) are classified as endocrine disruptors that are toxic to reproduction, which means that they may damage fertility or the unborn child. Both BPAs and phthalates are found in plastic containers available on the market today.

New research is being conducted on the health impacts of single-use plastic in medical procedures. Specifically, phthalate chemicals that are used in medical devices have been associated with alterations in autonomic regulation, heart rate variability, and cardiovascular reactivity. Researchers caution that plastic use is not without an impact and may affect a patient’s ability to recover from medical processes.

Broadly speaking, so-called "environmentally friendly" plastics fall into two types:

• Bioplastics/Biodegradable      plastics, which are typically produced from corn oil, orange peels,      starch, and plants. 
• Eco/recycled plastics, which are      simply plastics made from recycled plastic materials rather than raw      petrochemicals.

People may think these terms mean the same thing. But there is a difference between a "biodegradable" plastic (one that can take decades or centuries to break down) and a truly "compostable" material (something that turns almost entirely into benign waste after a matter of months in a composter or commercial composting facility). Compostable products have value when they meet the guidelines (e.g. a numerical stamp on the product) for composting but most importantly when facilities exist for commercial composting. Confusing jargon hampers public understanding, which makes it harder for consumers to grasp the issues and make positive choices when they shop. Here are some facts to consider about environmentally friendly plastics:

• When some biodegradable plastics decompose in landfills, they produce methane gas. This is a very powerful greenhouse gas that adds to the problem of global warming. 
• Biodegradable plastics and bioplastics do not always readily decompose. Some need exposure to UV (ultraviolet) light or relatively high temperatures and, in some conditions, can still take many years to break down. Even then, they may leave behind micro-fragments or toxic residues.
• Bioplastics/biodegradable plastics are made from plants such as corn and maize, so land that could be used to grow food for the world is being used to "grow plastic" instead. 
• Growing crops to make bioplastics comes with the usual environmental impacts of intensive agriculture, including greenhouse emissions from the petroleum needed to fuel farm machinery, and water pollution caused by runoff from land where fertilizers are used in industrial quantities. 
• Polylactic acid (PLA), a plastic substitute made from fermented plant starch (usually corn) is quickly becoming a popular alternative to traditional petroleum-based plastics. PLA is far from a panacea for dealing with the world’s plastic waste problem. For one, although it does biodegrade, it does so very slowly. According to Elizabeth Royte, writing in Smithsonian, PLA may well break down into its constituent parts (carbon dioxide and water) within three months in a “controlled composting environment,” that is, an industrial composting facility heated to 140 degrees Fahrenheit and fed a steady diet of digestive microbes. But it will take far longer in a compost bin or in a landfill packed so tightly that no light and little oxygen are available to assist in the process. Indeed, analysts estimate that a PLA bottle could take anywhere from 100 to 1,000 years to decompose in a landfill.

In net bioplastics do not necessarily offer a solution as they are resource intensive as well and their use as a substitute may eliminate some issues related to petroleum-based plastic but at the cost of generating other and unknown issues.