Reducing your exposure to pesky plastic particles

If you thought plastic pollution was just about bottles bobbing in the ocean, think smaller. Much smaller. Microplastics, those pesky fragments less than five millimetres across, are now so pervasive they’re airborne.

Dr Joel Rindelaub, from the Faculty of Science at the University of Auckland, wants people to know just how much plastic is swirling around in the air or ending up on our plates.

Rindelaub was part of a study revealing Auckland’s atmosphere is showered with the equivalent of three million plastic bottles every year. That is 74 metric tonnes of microplastics falling from the sky like invisible confetti.

Using advanced chemical techniques, the researchers detected particles as tiny as 0.01 millimetres, sizes so small they can slip past the body’s defences, lodge in lungs, and – if they are small enough –even cross into organs like the liver and brain.

“The smaller the size ranges we looked at, the more microplastics we saw,” Rindelaub says. And those smallest particles? They are the most toxicologically relevant. The paper noted: “Microplastics have also been detected in human lungs and in the lung tissue of cancer patients, indicating that the inhalation of atmospheric microplastics is an exposure risk to humans.”

So where do these airborne plastics come from? Everywhere.
Synthetic clothing fibres, car tyres, packaging and even ocean waves.

In fact, Rindelaub’s research suggests breaking waves in the Hauraki Gulf act like giant aerosol machines, flinging microplastics into the air. When winds whip across the water, Auckland’s microplastic count spikes.

Indoors, the situation is worse. Rindelaub’s team measured air in chemistry labs and found concentrations ten times higher than outdoors. Seven types of plastic were detected, including materials common in building supplies and lab equipment. Alongside the plastics were chemical additives like phthalates, endocrine disruptors, floating through the air at hundreds of nanograms per cubic metre.

“We need to know much, much more about our exposures and the potential health risks,” Rindelaub warns.

Globally, scientists are trying to standardise methods for measuring microplastics because most past studies have undercounted the tiniest particles, the ones most likely to infiltrate our bodies.

So what is the message? Microplastics are not just an environmental nuisance; they pose a significant personal health risk. They are in the air we breathe, the water we drink and the food we eat.

But there are small steps we can take to reduce exposure, especially in the kitchen. Rindelaub talked to Joelle Ireland, the host of the University’s Expert Tips in Two Minutes series.

“One of the big concerns is the additives to the plastic, the things that give it its physical properties,” says Rindelaub.

“That has to do with their chemical formulations, the chemicals they add to the plastic themselves. Some of these substances can have properties that disrupt hormone systems, which could become an issue in the future.”

But he says there’s heaps we can do at home to reduce exposure.

“So when we're eating and drinking, we need to avoid using plastic in the kitchen whenever possible.

He says people should reheat food in glass, never plastic.

“Avoid putting takeaway containers in the microwave, and don't use a plastic tea kettle to make your morning tea!”