Microplastics: A Vast, Barely Visible Problem

For decades, miniscule microplastics and invisible nanoplastics from varied sources have accumulated in oceans, air, soil, food and bodies, creating a planetary pollution problem of daunting proportions. Credit: m.malinika/iStock.

Reading Matt Simon’s disturbing new book, “A Poison Like No Other: How Microplastics Corrupted Our Planet and Our Bodies,” I found a question running through my head like a refrain: Why did we not recognize this massive problem of miniscule plastics earlier?

Simon, a science journalist at Wired magazine, dissects how microplastics — fragments and fibers less than 5 millimeters long (roughly a pencil eraser’s width) — now pervade bodies, air, oceans and soils. “The past half-century environmentalists have been on a crusade against single-use wrappers and bottles,” he writes, but “all the while microplastics have spread like a plague around the world and hardly anyone noticed.”

Microplastic pollution was “overlooked for decades because most of it is invisible to the naked eye,” Abby Barrows, a marine researcher on Deer Isle who in 2012 was among the first scientists to start sampling coastal waters for microplastics, explained to me. Researchers who observed the material under microscopes may have assumed that the plastics were due to contamination of samples, she added, despite an early warning of the problem in scientific literature.

In 1972, oceanographer Edward Carpenter published his discovery of small plastic fragments floating in the Sargasso Sea, a portion of the Atlantic Ocean far off the southeastern U.S. coast that is encircled by major currents. “The increasing production of plastics, combined with present waste-disposal practices,” he wrote, “will probably lead to greater concentrations on the sea surface.”

Plastic production did explode in the decades that followed, taking over our lives in what Simon calls “a quiet coup.” And, as Carpenter had predicted, a tsunami of marine microplastics followed.

Filling the seas

A 2020 study estimated that up to 46 billion pounds of microplastics are now suspended in the top 650 feet of the Atlantic Ocean. The volume of microplastics is still rising, with the generation of single-use plastics at a record-breaking high, so we’re not yet, in the words of one team of international scientists, “at the peak of toxic release” from all the plastics overtaking our planet.

With global plastic waste expected to triple by 2060 and plastic recycling rates hovering around 5 percent, marine microplastic concentrations could — by one estimate — be 50 times what they are now by 2100.

Already microplastics are interfering with the base of the marine food web, affecting both phytoplankton and zooplankton. “Not many marine animals are big enough to choke on a whole plastic bag,” Simon writes, “but a great many diminutive creatures can choke on microplastic they mistake for prey.” Research has shown that when copepods (tiny crustaceans) consume plastic, they eat far less real food, leading to reduced energy, egg size and growth.

Researchers affiliated with Bigelow Laboratory in East Boothbay found that lobster larvae, which gather at the ocean surface where microplastics concentrate, can experience reduced oxygen consumption since the particles accumulate in the vicinity of their developing gills as well as in their digestive systems.

Magnets for toxic chemicals

For marine life in the Gulf of Maine, which already faces markedly warmer and more acidic waters, microplastic exposure adds multiple threats. Some toxic chemicals leach directly from the constituent plastic, while others — heavy metals, pesticides, pharmaceuticals, per- and polyfluoroalkyl substances (PFAS) and PCBs — collect on the surface, drawn in from the surroundings. The more weathered the microplastics become, one study found, the more effectively they accumulate chemicals. Plastic particles and fibers can also gather scads of viruses and bacteria.

The toxic hitchhikers accompany microplastics into the guts of plankton, fish, shellfish and — ultimately — humans. In a comprehensive 2021 study, three-quarters of the commercially fished species assessed had ingested microplastics.

Once inside bodies, plastics continue to degrade and can transform into nanoplastics small enough to enter cells (particles between 1 and 1,000 nanometers, less than one-hundredth the thickness of a sheet of paper). Within fish, scientists have already found that nanoplastics cross from guts into blood and into the brain.

Microplastics enter us, not just through ingestion of marine and land-grown foods, but in the air we breathe. Indoors, we routinely inhale microfibers shed from synthetic clothing and carpets, and outdoors winds carry microplastics (from varied sources, including the degradation of synthetic tires) and nanoplastics great distances. Scaling up from a study done in the American West, Simon estimates that atmospheric deposition of microplastics across the U.S. is now the equivalent of 5 billion water bottles annually.

The extent of damage that microplastics inflict inside us is not yet clear, but their presence in organs is documented. Studying a small sampling of autopsies on nonsmokers, Brazilian researchers estimated that the “an average person might have 470 microplastics in their lungs,” Simon writes. Assessing colon tissue removed from 11 Malaysian patients, nine of whom had cancer, researchers found an average of 800 microplastics per ounce, many of them transparent filaments. It was not clear, Simon writes, whether those clear fibers came from food wrappers or were due to “colorants and other additives in microplastics leach[ing] out in this hot and acidic environment.”

Microplastics often carry endocrine-disrupting chemicals, such as PFAS and Bisphenol A, that interfere with the body’s capacity to produce and break down hormones. Because these chemicals can affect egg and sperm cells in children, their impact can be generational. In 2021, Simon reports, microplastics were found in human placentas and in the first stools of newborn babies.

The need for ‘a fundamental renegotiation’ with plastics 

Microplastics are not just threatening public and ecological health but are aggravating climate upheaval — releasing carbon as they degrade and settling on glaciers and polar ice where they make those surfaces less reflective and more likely to absorb solar energy. The plastic waste disaster and climate crisis are one in the same, Simon writes, both the product of fossil fuel corporations driven by “the sociopathic pursuit of profit.”

While there are actions consumers can take to reduce their use of plastic and minimize their exposure to microplastics, Simon makes clear that this problem demands a “fundamental renegotiation of our relationship” with plastic — and should involve an effort to “hold corporations responsible for this planetary vandalism.”

Maine took the lead among states in 2021 on one important step, which Simon unfortunately did not highlight: creating an extended producer responsibility (EPR) program for packaging. Now adopted by several other states, EPR will push manufacturers to reduce unnecessary plastic packaging and improve product design so that less plastic is used and more is recycled.

State actions only go so far though with a global-scale problem. Negotiations are underway for an international plastics treaty, and there’s far more that the U.S. should do as the top generator of plastic waste globally. A Break Free from Plastic Pollution Act awaits action in Congress; among Maine’s delegation, only Rep. Chellie Pingree is a co-sponsor.

Managing the microplastics mess we’ve created depends on more people understanding the scope of the problem. Simon’s book should help build the awareness that nearly all the plastics we use on a daily basis are on their way to becoming microplastic pollution.

© Marina Schauffler, 2023. All Rights Reserved. Column reprints available upon request