IT’S an all-pervasive pollution.

Tiny filaments of plastic are finding their way onto our plates.

And they’re coming from furnishings, carpet, car tyres, packaging and clothing.

A British study put Petri dishes on the table next to the dinner sets of three homes during mealtime.

Once the dishes were collected and the cleaning-up begun, the Petri dishes were sealed and taken away for analysis.

Under the microscope, researchers found up to 14 pieces of microplastic in each. When applied to the scale of a dinner plate, that means some 114 fragments are falling on your food and finding their way to your stomach in every meal.

HOUSEHOLD FALLOUT

Over the course of a year, an average person can expect to ingest between 13,700 and 68,400 fragments that have fallen out of the household air as dust and on to kitchen and dining ware.

The research team from Heriot-Watt University also sampled the amount of plastic entering our stomach through seafood: specifically, mussels. Each mussel contained less than two pieces of microplastic, despite rising plastic pollution levels in our oceans.

“These results may be surprising to some people who may expect the plastic fibres in seafood to be higher than those in household dust,” senior author of the study Professor Ted Henry says.

The authors say this indicates the greatest level of microplastic pollution in home-cooked meals mostly came from household dust — and not the cooking process or food chain.

But this could be set to change.

A MATTER OF SCALE

A new UK government report warns the amount of plastics in the world’s oceans is set to treble within the next decade.

And while images of birds, turtles and fish tangled in discarded plastic is distressing, it’s what’s happening on the microscopic scale that is affecting us all.

Plastic degrades. But it doesn’t go away.

Instead, it breaks down into small polymers.

Known as microplastics — anything 5mm in size or less — are becoming recognised as the greatest threat to marine environments around the world. They’re light. They’re easily tossed about. To many animals, they look like food.

They’re now being found in all elements of the food chain, from tiny krill through to predatory fish.

UNKNOWN IMPACT

Professor Henry says microplastic doesn’t automatically mean toxic. At least, nowhere near the scale of the other great marine pollutant — mercury.

But it could potentially be harming living organisms — including humans — in other ways.

Not enough is yet known.

It can accumulate in stomachs. Whether or not the tiniest microplastics, smaller than 1000 micrometers, can be absorbed through skin walls is not yet known.

What is suspected, Professor Henry says, is that microplastics act as ‘transport’ for other toxic substances, such as DDT or hexachlorobenzene. These stick to plastic and can therefore gather in higher concentrations within a body than they would otherwise.

“There are important gaps in scientists’ knowledge that need (to be) filled, particularly where plastic particles are likely to accumulate in large amounts over long periods and how this potentially affects ecosystems,” Professor Henry writes.

We must avoid undue speculation and overstating risks, and instead engage with the actual evidence. Otherwise it will detract from our ability to manage plastic pollution in the most effective way and have a clear sense of the right priorities.
Very small.