By Vicky Fong
Seafood consumers are advised of the risks of mercury intake, but recent studies show that they should also be aware that their meals might come with a side order of plastic.
So how does plastic end up in the oceans, get eaten by the fish, and make its way into our bodies?
With our increased dependency on disposable items, the production of plastic has increased over the past few decades. Through the sewage systems, approximately 10% of plastics produced annually finds its way to the water, making up 60-80% of all of the trash in the our oceans.
Another surprising source of marine plastic debris is our clothing. Synthetic materials like polyester contain plastic microfibers, and every time it goes through the wash, up to 1,900 plastic microfibers flushes into the oceans.
A mix of UV radiation, heat and waves causes plastic to break down into smaller pieces over time. These microplastics are eaten by microscopic organisms like plankton, that are then eaten by fish and other marine life. They accumulate in their tissues and organs and pass the plastics up the food chain, a process known as bioaccumulation. Who’s the top predator at risk? Humans.
Researchers in Europe studied shellfish consumers and found the average exposure amounted to 11,000 microplastics every year. More locally in the US, anthropogenic (from humans) debris was found in 67% of all fish species sampled.
Should we be worried about consuming plastic? Some of it naturally passes through our digestive systems, and insufficient research has been carried out on the direct effect plastic has on our bodies. The metals and chemicals that the plastics soak up, however, should trigger our concern.
Microfibers and microplastics absorb PBTs – Persistent, Bioaccumulative and Toxic chemicals – that pose significant risks to human health. These include heavy metals, pesticides and harmful components from fossil fuels. Continued exposure to such toxins could impede our neurological functioning, disrupt our hormone systems, and even cause cancer cell growth.
So next time you pick fish on the menu, be advised…