Microplastic emissions are up to 10,000 times LOWER than we thought, promising study reveals

The growing threat of microplastics might be daunting, but a promising study now suggests that the situation might not be as dire as previously thought.

Researchers from the University of Vienna found that microplastic emissions are up to 10,000 times lower than previous studies have estimated.

Until now, scientists have either made 'bottom–up' estimates based on models of human activity or based their estimates on emissions data from a single region.

In this new study, researchers combined 2,782 measurements of microplastic concentrations from 283 locations between 2014 and 2024.

These measurements were then compared with existing models to arrive at a new estimate for the world's microplastic footprint.

However, the study's authors told the Daily Mail this does not mean we don't need to worry about microplastics.

While it was believed that microplastics mainly entered the air from the seas, these estimates show that land sources contribute 20 times more microplastic particles.

That means the total microplastic emission from land into the air is still about six hundred quadrillion particles per year.

Microplastics are tiny fragments of plastic measuring between one micrometre and five millimetres in size.

On land, these are emitted into the atmosphere by vehicles through tyre and brake pad wear, as well as through the breakdown of larger pieces of plastic in the ground and oceans.

From the oceans, microplastics are largely emitted via sea spray as breaking waves  launch microplastic–rich bubbles into the air.

Scientists believe that these plastics have now spread into almost every part of Earth, with studies discovering microplastic particles at every ocean depth.

Recent surveys found that this 'plastic smog' even extends to the bottom of the Mariana Trench, the deepest point in Earth's oceans.

However, scientists still don't fully understand how microplastics cycle through the atmosphere.

At the same time, localised measurements of microplastic concentrations in the atmosphere can vary by several orders of magnitude.

For example, along the southeast coast of China, measurements range from just 0.004 particles per metre cubed to 190 particles per metre cubed.

Likewise, the rate at which microplastics are deposited from the atmosphere also ranges between extremes.

In the suburbs of China's megacities, scientists have recorded just 50 particles per square metre per day, while urban locations in the UK have reported up to 3,100 particles.

These big local differences make it very difficult to estimate how many microplastic particles are emitted into the atmosphere each year.

This is extremely important since there is a growing body of evidence to suggest that high levels of microplastic exposure can be detrimental to the health of humans and animals.

In their new paper, published in Nature, the researchers attempt to solve this problem by using a much larger data set.

Lead author Dr Ionna Evangelou told the Daily Mail: 'Previous studies used atmospheric measurements from a small region over the Western USA to estimate the atmospheric microplastic emissions globally.

'On the contrary, in this study, we tried to utilise the available knowledge on the microplastic abundance in the atmosphere based on reported measurements globally.'

The researchers found that average concentrations of microplastics in the atmosphere were 0.08 particles per cubic metre of land and just 0.003 per cubic metre of the sea.

Using these concentrations, Dr Evangelou and her co–authors scaled up previous emissions models to get a more realistic total estimate that is between 100 and 10,000 times lower than earlier suggestions.

The researchers now predict that total yearly microplastic emissions are six hundred and ten quadrillion particles from land and twenty–six quadrillion from oceans.

However, that doesn't mean the world can now relax about microplastics.

While this study is a big improvement on previous estimates, the researchers say it is still missing some important data.

Crucially, many measurements lack 'crucial' information on the size and distribution of microplastics.

Dr Evangelou says: 'Lower emissions mean lower airborne concentrations, but numbers alone don’t tell the whole story.

'For instance, health impacts also depend on the particle size, shape, the additives or attached pollutants, and, of course, the exposure duration.'

That means it still isn't certain how damaging these will be to human health.

Likewise, even with the improved data, there are still very large margins of error up to one order of magnitude in this new estimate.

Regional uncertainties, in which concentrations could vary from town to town, could be even higher.

Co–author Dr Adreas Stohl told the Daily Mail: 'We do not really know what level of microplastic is actually safe for human health or the environment.'

Dr Stohl adds: 'Also, we expect emissions to increase in the future.'