The average American adult consumes between 126 and 142 tiny particles of plastic every day, and inhales another 132-170 plastic bits daily too, according to new research from the University of Victoria.
The study, published in the journal Environmental Science and Technology, attempted to estimate how many microplastic particles people consume — and these numbers are likely an underestimate, the researchers say.
WATCH: (March, 2018) Scientists found hundreds of microplastic particles in a small sample of Vancouver seawater
Microplastics, which are pieces or fibres of plastic smaller than 5 mm (about the size of a grain of rice), are a growing area of research in the scientific community, and have been found in fish, water, table salt and many more places, including human stool, in one small study.
To figure out how much people were consuming, the researchers combined known quantities of microplastics in various foods and in the air with the diets recommended by the food guide and estimates of how much people eat of those foods.
For example, seafood was estimated to have 1.48 microplastic particles per gram. The recommended weekly seafood intake for young men is 281 grams per week. So according to this, that person would be eating about 414 microplastic particles from seafood alone.
But according to lead researcher Kieran Cox, a PhD candidate at the University of Victoria, scientists have only looked at the microplastic content of about 15 per cent of our diet — meaning they don’t know how much plastic is in the rest.
“By not being able to look at that 85 per cent, we are missing a large piece of the puzzle, which, if the data is representative, is probably a large magnitude increase in plastic,” he said.
Because the study examined existing literature — which counted plastic particles rather than weighing or measuring the plastic, for example — the researchers couldn’t come up with a more precise measurement than the number of particles. This means they don’t know whether their estimate of 52,000 ingested particles each year amount to a teaspoon of plastic, or a tiny pinch.
They also don’t know what it means for your health.
“It is still unclear to what extent our estimate of human consumption of (microplastics) poses a risk to human health,” the authors of the study wrote.
This calculation is just a starting point, said Peter Ross, vice president of research at Ocean Wise, an environmental conservation organization.
“It’s simply part one of a three-part process,” he said. “Part one is do the exposure, part two is understand what the harm is based on different studies, and part three is you do a risk assessment that you can apply to the larger population.”
To him, the exact amount of plastic people ingest doesn’t matter that much.
“The point is that everybody is ingesting microplastics.”
“And number one, we don’t know where these things are coming from, and number two, we don’t have a clue what they might do to us,” he said.
WATCH: (June 5, 2018) Swimmer begins record Pacific Ocean crossing in effort to expose plastics in world’s waters
There are two ways that plastics can cause harm, Ross said. The first is that chemicals in plastic can leach out into our bodies. A particularly famous example of a plastic-related chemical was Bisphenol-A (BPA), which has been removed from baby bottles after it was linked to brain and developmental issues.
The second way plastic can cause harm is by its physical presence, Ross said. In animals, “We know that plastic can suffocate. It can block our intestines.” Some animals might eat it and feel full, but not get enough nutrition, he said.
“Micro plastics are just like snowflakes,” he said. “There’s an infinite number of shapes and sizes and chemistries.” Each one might have a slightly different effect.
Microplastics get into the environment in a number of ways, Cox said. The most common type of microplastic is fibres, he said. “Washing your clothes and having that water go out into the ocean, that is a large amount of plastic.”
Single-use plastics also contribute, he said, as tiny bits of plastic can flake off.
As plastics get into the environment, they can wind up in your food, he said. And sometimes, they can get directly from containers into your food — like with bottled water. Drinking bottled water meant an extra 90,000 microplastic particles every year compared to tap water, the researchers found.
“A single choice like mitigating bottled water, added up over the year, has a big consequence,” Cox said.
Ross isn’t sure what can be done to cut down the amount of plastic in the environment, though.
“It’s pretty late in the game,” he said. “We find microplastics all over the Arctic and our seawater samples that we’re collecting all up and down the coast of B.C.
“If we can determine that these things are harmful, then we’ve obviously caused some uncertain amount of damage in the environment or to human health.”