Researchers Accidentally Discover That It’s Raining Plastic

September 9, 2019

You probably know that plastics are a huge source of environmental pollution, but it may be surprising to find out that microplastics are now detected in the air, the seafood we eat and even in our bodies.

Microplastics are both tiny (smaller than 5 millimeters in size) and toxic. These tiny particles are hiding in many surprising places. Do you know the latest source? Precipitation. That’s right, according to researchers, today’s weather report: it’s raining plastic.

It’s Raining Plastic: Study Details

The researchers behind a 2019 study collected atmospheric wet deposition (rain, snow or fog) samples in eight locations along the Front Range. This is a mountain range of the Southern Rocky Mountains located in the central region of the state of Colorado.

Researchers collected, filtered and analyzed precipitation samples. They were studying nitrogen pollution and not even looking to find plastic particles, but that’s exactly what they found. More specifically, the “unanticipated and opportune” discovery was that over 90 percent of the samples collected contained plastic.

The study highlights the fact that it’s not just urban sample areas, like Denver and Boulder, affected by plastic pollution. Even a remote collection site — Loch Vale in Rocky Mountain National Park — harbored plastic fibers in its washout samples. So it’s not just raining plastic in cities, but in remote, nature-saturated areas as well.

What’s the main source of plastic? The team of researchers from the U.S. Geological Survey (USGS) observed that the colorful strands of plastic appear to likely be synthetic microfibers, which often make up clothing.

Since this study wasn’t aiming to research plastic pollution, there isn’t a clear conclusion on how the plastics made their way into the Colorado precipitation samples. However, past research with similar results in the French Pyrenees mountains suggests that plastic particles are capable of traveling in the wind hundreds or even thousands of miles. Microplastics are also found in our waterways and groundwater today.

According to Sherri Mason, a microplastics researcher and sustainability coordinator at Penn State Behrend, trash is the main contributor because an estimated 90 percent of plastic waste is not recycled, and as it slowly degrades it breaks down into smaller and smaller pieces. She points out that other sources include the plastic fibers which break off clothing each time they’re washed, as well as the plastic byproducts of many industrial processes.

Fast Facts: Microfiber Stats

Microfibers can come from natural materials such as cotton or synthetic materials such as polyester, acrylic or nylon.
Over time, any fabric will release microfibers, but while natural microfibers can break down more easily, synthetic fibers resist breakdown in the environment and therefore can increase in concentration over time.
Synthetic microfibers are a main source of microplastic pollution.
Polyester, acrylic, nylon and other synthetic fibers are estimated to be 60 percent of the material that makes up our clothing worldwide.
There may be 1.4 million trillion microfibers in the ocean according to an extrapolation based on research conducted by George Leonard, chief scientist for The Ocean Conservancy.
A recent study of stranded marine animals in the U.K. reveals that all 50 animals (across 10 species) contained microplastics; 84 percent of the plastic were synthetic microfibers.
Microfibers can translocate and accumulate within animals like seafood that are then consumed by humans.
Research reveals that 95 percent to 99 percent of microfibers may be captured in municipal wastewater treatment systems that are common in the United States.
Worldwide, farmers use sewage sludge that contains microfiber as fertilizer for crops.
Microfibers have also been found in tap water, bottled water, sea salt and beer.

Possible Health Effects of Microfibers

According to a scientific article published in Current Environmental Health Reports, “Microplastics may cause harm to humans via both physical and chemical pathways.”

The article warns that the potentially harmful health effects of microplastics may include:

Enhanced inflammatory response
Size-related toxicity of plastic particles
Transfer of absorbed chemical pollutants to the body
Disruption of the gut microbiome

According to a 2018 article published in Scientific American, “Small airborne particles are known to lodge deep in the lungs where they can cause various diseases, including cancer. Factory workers who handle nylon and polyester have shown evidence of lung irritation and reduced capacity (although not cancer), but they are exposed to much higher levels than the average person.”

In addition to negative effects on lung health, there are also concerns that microfibers negatively impact liver and brain health and may even increase the risk for brain damage.

How to Go on a Microfiber-Free Diet

According to the International Union for Conservation of Nature (IUCN), 35 percent of microplastic pollution comes from washing synthetic textiles.

Some of the best ways to reduce microfiber pollution:

Purchase clothing and bedding made from natural materials like organic cotton, hemp, wool and linen.
Buy secondhand clothes made from natural materials.
Educated friends and family members about pollution from microfibers.
Ask designers to consider using natural materials to create their clothing.
If you already own synthetic clothing and bedding, wash them less often and for a shorter period of time.
When cleaning out your dryer’s lint filter, place the lint in the trash rather than washing it down the drain.
Consider air drying clothing.
Use liquid laundry detergent since powders are known to scrub and loosen microfibers more so than liquid cleaners.
Put synthetic clothing into a filter bag before machine or hand washing to cut down on the amount of microfibers that go down your drain.

Final Thoughts

Researchers from the U.S. Geological Survey who were initially investigating nitrogen pollution wound up discovering that it’s raining plastic. Precipitation can now be added to the list of places where microplastics are found. Other places include soil, bodies of natural water, seafood and other animals, ground water systems and the air.

According to one of the researchers and USGS research chemist Gregory Wetherbee: “I think the most important result that we can share with the American public is that there’s more plastic out there than meets the eye. It’s in the rain, it’s in the snow. It’s a part of our environment now.”
In addition to environmental effects, the fact that it’s raining plastic is a major concern for human health. As research continues, we’re finding out how microfibers and other microplastics can negatively impact the health of our bodies, especially our lungs, livers, brains and gut microbiome.
This study and others reveal that microfibers from clothing made from synthetic materials are a main source of microplastic pollution. There’s a lot that can be done on an individual level to reduce microfibers. For starters, look for clothing and bedding made from natural materials like organic cotton. You can also decrease microfiber pollution by purchasing secondhand clothing, washing synthetic clothing less often and letting clothes air dry.
While it’s disturbing to find out that it’s raining plastic, the good news is that you can start reducing microfiber pollution today.