That plastic bottle that you saw floating ashore will eventually enter our food chain.
This is Part 2 of a blog series covering plastic pollution in Earth’s oceans. Read Part 1 here.
Impacts on climate change
Oil, gas, and coal are the fossil-fuel building blocks of plastics. Thus, the beginning of plastics’ life cycle really begins with oil and gas development. Extraction and transportation of these fossil fuels is a carbon-intensive activity, and land disturbance contributes to greenhouse gas emissions associated with extraction. Also, each mile of the oil extraction pipeline must be surrounded by cleared land. This can equal to 1.686 billion metric tons of CO2 released into the atmosphere as a result of clearing.
In the US alone, emissions from plastics incineration in 2015 were equivalent to 5.9 million metric tons of CO2. If plastics production and incineration increase as expected, greenhouse gas emissions will increase to 49 million metric tons by 2030 and 91 million metric tons by 2050. Moreover, incineration facilities are disproportionately built near low-income communities, unevenly exposing a certain portion of the population to plastic-derived damage. This makes plastic pollution also a humanitarian issue of social and economic equality (https://yaleclimateconnections.org/2019/08/how-plastics-contribute-to-climate-change/).
As some experts say, plastics do not break down, it breaks up. The action of “break up” allows the formation of thousands of micro pieces from one big piece. Over time, with the process of erosion, plastics in the ocean break up in fragments. Fragments of any type of plastic less than 5 mm (0.20 in) in length are categorized as “microplastics”.
Primary microplastics are those that are already 5.0 mm in size or less before entering the environment and can come from microfibers from clothing, microbeads, and plastic pellets. Secondary microplastics derive from the degradation of larger plastic products through natural weathering processes after entering the environment. These can originate from water and soda bottles, fishing nets, plastic bags, microwave containers, tea bags.
Microplastics are an extreme concern because we still do not know the extent of their hazard. This slow degradation process can take hundreds of thousands of years. This gives microplastics extremely high durability and consequently a high risk of ingestion. Yes, that plastic bottle that you saw floating ashore will eventually enter our food chain.
A plastic food chain all the way to us
Microplastics have the ability to absorb free-floating chemicals in the ocean. Moreover, they easily look like fish food! When these fragments-and-chemicals combo are ingested by marine animals, chemical toxins are released and enter the bloodstream. Once in the organism, these toxic chemicals accumulate in fish fat and muscles tissues. Now this fish which has an accumulation of plastic toxins in its tissue enters food production, and is sold at the market, or served at a restaurant. Toxins attached to the microplastics and ingested by the fish will inevitably enter the bloodstream of the human who will be eating it. Plastic toxins can damage the immune system, upset the gut’s balance, interfere with the body’s endocrine system, causing developmental, reproductive, neurological damage, and can also be carcinogenic.
An example is Estrogenic Activity. When a chemical like BPA is released from plastic and enters the body, it mimics the hormone estrogen. The risks of plastic ingestion for humans are not only from fish. An article from National Geographic highlights the detection of microplastics in beer, salt, seafood, sugar, alcohol, and honey. People who meet their recommended water intake through tap water ingest 4,000 plastic particles annually, while those who drink only bottled water ingest an additional 90,000. Overall, humans may be consuming anywhere from 39,000 to 52,000 microplastic particles a year. We have not considered ourselves to be a potential plastic pollution impact, but we are.
One Health Implications
Plastic pollution is clearly a One Health issue. As we can see, it affects the Earth in all its realms, from planktons, to land, to baby seals, to the human endocrine system. The pervasive use of plastic proceeded so unsustainably for the last decades, that now the planet is left to deal with, literally, a lot of garbage. In the last 10 years, we made more plastic than in the last century, and almost every bit of plastic ever made still exists.
If you want to help the ocean, the planet, and yourself, the One Health Center encourages you to take action. Think critically about the materials that will replace plastics, boycott single-use and disposable plastics, reuse bags as many times as possible, purchase items second-hand and stop buying bottled water. Small actions can make a big difference. Only by reacting, can we save a planet that is home to us and millions of other creatures. Thank you!
By Costanza Manes, One Health Research Fellow