Humans have created 8.3 billion metric tons of plastic since 1950, a weight equivalent to 1 billion elephants.

More than 75% of this plastic has been thrown away, left to disintegrate throughout the global environment. It takes a long time for plastic to break down and, as it does, it breaks into smaller and smaller pieces — invisible microplastics as small as cells, eventually — that are now blanketing the planet’s oceans, air, and land.

And this pollution is affecting humans in ways that are largely unknown.

For example, 83% of tap water samples around the world were found to contain plastic fibers, according to a recent study conducted by Orb Media. Samples were taken from throughout Europe, the US, India, Ecuador, and more than a dozen other countries.

Read More: Arctic Waters Could Soon Be Choked by Plastic, Expert Warns

The country with the highest level of plastic contamination was the US, with 94% of taps containing traces of plastic.

The average US sample contained 4.8 fibers of plastic, compared to an average of 1.9 fibers in Europe.

That means that with nearly every cup of water, Americans are ingesting plastic fibers.

Global Citizen campaigns on the Global Goals, which call for universal access to clean water and healthy environments. You can take action on these issues here.

The problem of contamination touches all sources of public water, the researchers argue, contesting that plastic literally pervades the atmosphere.

In Beirut, Lebanon, a city that gets all of its water from protected natural springs, 94% of tap water samples were found to have plastic.

Water bottles were also found to contain traces of plastic fibers.

Read More: Why You Should Absolutely Never Drink Bottled Water Again

That’s because plastic isn’t simply seeping into water supplies from land-based pollution. Microplastics are also getting swept up by the wind and falling from the sky, filling the air humans breathe, covering crops, and entering sources of waters.

In Paris, for instance, a team of researchers in 2015 estimated that 10 tons of plastic fibers fell from the sky each year and even entered people’s homes.

The scientists behind this latest study are calling for further investigations into the phenomenon and for medical researchers to begin examining the health consequences.

But they warn that, extrapolating from research into how marine animals are affected by plastic, the results are likely to be grim.

Read More: 7 Eco-Friendly Alternatives to Plastic Straws to Help Save the Oceans

“We have enough data from looking at wildlife, and the impacts that it’s having on wildlife, to be concerned,” Dr. Sherri Mason, a microplastic expert at the State University of New York in Fredonia, who worked on the analysis, told The Guardian. “If it’s impacting [wildlife], then how do we think that it’s not going to somehow impact us?”

Microplastic fibers can carry bacteria from sewage, toxic chemicals, and other pathogens, according to research cited by The Guardian.

These pathogens are quickly released when in the gut of an animal, and the fibers themselves release chemicals intrinsic to the plastic.

As the human body processes these pollutants, it’s unknown what effect they are having.

“We are increasingly smothering ecosystems in plastic and I am very worried that there may be all kinds of unintended, adverse consequences that we will only find out about once it is too late,” said Roland Geyer, from the University of California and Santa Barbara, who led the study.


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83% of All Tap Water Around the World Has Plastic Fibers In It

By Joe McCarthy