'Plastic rain' poses health and environmental risks, could COVID be among them?

Jim Waymer
Florida Today
Janice Brahney, an assistant professor of environmental biogeochemistry at Utah State University, holds a tray of microplastics.

Coronavirus affects all things from barflies to baking supplies, so why not the rain? 

Could viruses like the new one wreaking havoc worldwide be hitching rides on microscopic airborne plastics, then winding up in our lungs? Some scientists think so. But nobody knows for sure how probable a pathway to infection that is, or what other multitude of health risks cling to this emerging environmental threat. 

These so-called microplastics lurk everywhere. Mostly, they are the tiny fibers from synthetic clothes that go down our drains with laundry water, enter the air and water cycle and fall back down on us as "plastic rain." Researchers are asking what health threats these pose, and wondering if even viruses like the one that causes COVID-19 might be riding in on us via all these lofting airborne plastics.

New research is revealing an emerging concern that airborne microscopic plastics and the resulting "plastic rain" that pulls them from the sky may be much more widespread than formerly thought. And all that synthetic fallout could have even worse health and environmental implications than acid rain, recent studies suggest.

Where there is dust, there is microplastic, a new study by Utah State University shows: The stuff even makes its way to the most remote stretches of the globe, especially at high elevations like Rocky Mountain National Park where lofting plastic particle and mountain often meet.

"I think it's pretty surprising considering how remote these locations are," Janice Brahney, assistant professor of environmental biogeochemistry at Utah State University, said of microplastics she finds far from urban areas in the central western and southern United States. Her study was published last month in the journal Science.

Microplastics plague the beach at Lori Wilson Park in Cocoa Beach. Many pieces were found June 9, 2018, during the FLORIDA TODAY-Keep Brevard Beautiful Summer Series beach cleanup.

Brahney and her colleagues estimate more than 1,000 metric tons of plastic particles — mostly synthetic microfibers used for making clothes — fall out annually within national parks and other protected areas of the central western and southern U.S. That's 132 plastic bits per square meter every day.

"These are what we would consider background deposition rates," Brahney said.

But biologist aren't sure to what extent microplastics and their toxic "hangers-on" harm humans and wildlife. The issue has grabbed scientific and public attention because, "it could be the organisms at the very base of the food chain" that the plastics harm first, causing cascading ill effects up the chain, says Maia McGuire, a Sea Grant agent at University of Florida.

"Were don't know what the food chain impacts are likely to be," McGuire said. "We do know chemicals detach from plastics and move up food chain, but what impacts those have, we don't know."

Toxic chemicals, viruses and bacteria cling to microplastics. The plastic particles then aerosolize out of  water and blow onto land in sea breezes — hovering there for us to breathe them in. They penetrate deep into lungs, with unknown consequences. They also are taken in by zooplankton and the tiny fish that gobble them up. Plastics then work their way from there up the food chain, to us. 

"They are within the respirable size range," Brahney said of the microplastics she finds practically everywhere and photographs under her microscope. "They can be inhaled and impacted on lung tissue. There are a lot of concerns for ecology as well. I think we just don't fully understand what those implications are."

Brahney and colleagues sampled rain and air, using collectors in 11 national parks and protected areas. They found 30% of sample particles were microbeads, which the researchers suspect originate from industrial paints and coatings. They collected samples over a year's time and found 98% of samples contained microplastic particles. On average, 4% of captured atmospheric particulates were synthetic polymers.

Janice Brahney took this picture through her microscope for a recent study of microplastics in remote areas of the country. The study, published in June in the journal Science, found widespread microplastics falling out from the air.

Tiny toxic threats 

Microplastics are defined as bits of plastic less than 5 millimeters. They are the broken-down shards of our synthetic surroundings. Nylon and polypropylene fibers are among the most common. Metals, toxins and harmful additives associated with plastics accumulate on the itty-bitty plastic bits.

Harm to humans and wildlife is yet unknown because the research topic is so new. But biologists say some recent studies have found toxic chemicals known to cause a host of ill-effects in humans clinging to the plastics. Substances such as Bisphenol A and phthalates — which can cause cancer and endocrine disruption in humans — and other plasticizers used to increase flexibility, durability and transparency of plastics also have shown up in whales and other marine life.

The Utah researchers' findings suggest atmospheric forces are whisking microplastics just about everywhere on the planet.

And it's expected to get worse.

If the current pace of plastic waste continues, volumes will almost double from 260 million tons per year (in 2016) to 460 million tons per year by 2030, according to the management consultancy McKinsey & Company.

That's not to mention all the plastics already out there. 

By 2025, 11 billion metric tons of plastic are projected to accumulate in the environment by 2025, according to the USU study. The Utah researchers showed that urban centers and re-suspension of microplastics from soils or water are the principal sources for wet-deposited plastics

Biologists worry too much microplastic in soil could change the temperature and water flow in some soils, stunting plant growth. 

The University of Florida's Institute for Food and Agricultural Sciences (IFAS) — which runs a microplastics awareness project — describes the ubiquity of the microplastics problem as follows: 

"Wash your face, brush your teeth, you just may be adding microscopic bits of plastic into the aquatic environment," IFAS says on its Florida Microplastics Awareness Project (FMAP) page

FMAP is a citizen-science project that was funded in 2015 by an outreach and education grant from the National Oceanic Atmospheric Administration.

McGuire, a marine biologist and Sea Grant Agent at UF, remains skeptical of the Utah study, and similar microplastics research. It's all so new. "There are so many assumptions they've made," McGuire said. "There's all sorts of room for error. This isn't set in stone. This is a really new field of research."

Uncertainties aside, McGuire sees microplastics as a serious emerging issue of ecological concern, given that some plastics take centuries to break down.

"Plastics don't biodegrade," McGuire said. "They're going to be around for a very long time. All plastics will become microplastics over time."

Janice Brahney took this picture through her microscope for a recent study of microplastics in remote areas of the country. The study, published in June in the journal Science, found widespread microplastics falling out from the air.

Do microplastics spread COVID-19?

But could more microplastics make outbreaks of viral diseases such as COVID-19 even worse than they'd otherwise be? One recent pre-print, not peer reviewed scientific literature review by environmental scientists in Nigeria, Japan, Bengladesh and Nepal speculated that a virus, such as the one that causes COVID-19, can cling to microplastics, potentially contributing to human health risk.

Studies show the virus can remain infectious on surface of plastics for several days under room temperature and in aerosol for up to three hours. The novel coronavirus is about the size of the Human Immunodeficiency virus (HIV), so more than 200 million coronaviruses would fit on the period at the end of this sentence.

In hospitals or households, thousands of particles of microplastics or nanoplastics can fallout on surfaces, the environmental scientists noted in their review. Viruses from the ill can drop on these particles and last up to three days, absent proper cleaning. During those three days, the particles can be re-suspended in the air with dust, risking infection when inhaled, the researchers said.

Science can't yet say whether such an "indirect transmission route" is probable, the researchers noted. 

But the researchers speculate that SARS-CoV-2 clings to plastics via biofilms that form on their surfaces, then get deposited more than 60 miles away — a theoretic possibility, they say, of why some regions appear to have had COVID-19 outbreaks without documented history of travel to hot spots of the disease or known contact with an infected person.

Janice Brahney took this picture through her microscope for a recent study of microplastics in remote areas of the country. The study, published in June in the journal Science, found widespread microplastics falling out from the air.

Plastic bits clog wildlife

As with humans, the health risks to wildlife from microplastics also remains shrouded in mystery.

But plastics show up in just about every type of organism where biologist have looked — typically as small synthetic fibers in their guts. Researchers have documented more than 180 animal species that ingest microplastics, including sea turtles. In several species, plastics block the digestive system, damage organs and result in reduced feeding, growth rates and reproductive failure.

Birds eat plastic bits, think they're full, and then starve. Plastics lodge in crab gills, decreasing their ability to respire. Microplastic has shown up in the circulatory systems of wild animals as well.

Plastics lodge in crab gills, decreasing their ability to respire. Most oysters appear unaffected.

Janice Brahney took this picture through her microscope for a recent study of microplastics in remote areas of the country. The study, published in June in the journal Science, found widespread microplastics falling out from the air.

But in 2017, University of Central Florida researchers found crabs and oysters from the Indian River Lagoon harbor tiny bits of plastic fibers. They also found plastic fragments and plastic beads in the water, oysters and crabs in the Mosquito Lagoon, part of the Indian River Lagoon system. The UCF researchers say old fraying boat ropes, fishing equipment, fibers from synthetic clothes and other broken-down plastic bits are the source.

"Microplastics are everywhere, so it is not surprising that we breathe them in constantly," said Linda Walters, a UCF biologist. "We also eat loads of plastics each day. My class this past spring found about 40 pieces of plastic in each Ziploc sandwich bag."

Walters says many of the microplastics she and her students find in lagoon are the fallout from aerial contamination. "It is rare to have a liter sample of (lagoon) water that is free of plastic pollution," she said.

Another troubling source is stormwater outfalls that carry runoff to the lagoon, she added. 

The UCF researchers speculated that the higher concentration of microplastic in Mosquito Lagoon might be due to it having few openings to the ocean for tides to flush out pollution.

But plastics plague offshore waters as well. Florida marine scientists for years have found almost all of the baby sea turtles that wash up dead on Space Coast beaches have plastic in their guts, some with almost nothing but plastic.

Janice Brahney took this picture through her microscope for a recent study of microplastics in remote areas of the country. The study, published in June in the journal Science, found widespread microplastics falling out from the air.

The baby turtles eat the floating tar from ship fuels and plastic shards within weeks of being born, when they journey 25 to 45 miles offshore to feed in the Gulf Stream.

Shards of old milk bottles, bleach bottles and clear plastic bags are among the most common sources, state biologists say, some of it washing down the Mississippi from Missouri decades ago.

The problem could get worse. Plastic debris has drastically increased within the past few decades, accounting for 60 to 80 percent of marine debris, the UCF paper notes.

In 1989, the Marine Plastic Pollution Research and Control Act made it illegal to dump plastic at sea and U.S. navigable waters. But the law is difficult to enforce, wildlife officials say.

Global production of plastics has grown from 1.7 million tons in the 1940s to 311 million tons by 2014 and is expected to double again in the next 20 years, according to the World Economic Forum.

Janice Brahney took this picture through her microscope for a recent study of microplastics in remote areas of the country. The study, published in June in the journal Science, found widespread microplastics falling out from the air.

So what do we do about it?

The Florida Microplastics Awareness project points to reusable bags, checking labels on personal care products, and pitching in on beach cleanups.

As of July 2017, it became illegal to make rinse-off cosmetics with plastic microbeads in the U.S.

But those beads can take decades to centuries to break down.

With so much synthetic fiber from textiles out there, it might just take the clothes off our backs to stave off a microplastics ecological meltdown — or at least making them out of more biodegradable materials.

"We need to wear clothes and we need plastics for some really important applications," Brahney said. 

"We definitely overuse plastics," she added. "So I think the solution is everybody making changes." 

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Jim Waymer is environment reporter at FLORIDA TODAY.

Contact Waymer at 321-242-3663                                         

or jwaymer@floridatoday.com.

Twitter: @JWayEnviro

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