Scientists first spotted the Blob in late 2013. The sprawling patch of unusually tepid water in the Gulf of Alaska grew, and grew some more, until it covered an area about the size of the continental United States. Over the course of two years, 1 million seabirds died, kelp forests withered, and sea lion pups got stranded.

But you could have easily missed it. A heat wave in the ocean is not like one on land. What happens on the 70 percent of the planet covered by saltwater is mostly out of sight. There’s no melting asphalt, no straining electrical grids, no sweating through shirts. Just a deep-red splotch on a scientist’s map telling everyone it’s hot out there, and perhaps a photo of birds washed up on a faraway beach to prove it. 

Yet marine heat waves can “inject a lot of chaos,” said Chris Free, a fisheries scientist at the University of California, Santa Barbara. It’s not just gulls and sea snails that suffer. Some 100 million Pacific cod, commonly used in fish and chips, vanished in the Gulf of Alaska during the Blob. In British Columbia and the Pacific Northwest, salmon runs – and the fishing industry that depends on them – floundered. The acute warming also triggered a toxic algal bloom that disrupted the West Coast’s lucrative Dungeness crab business. 

“It occurred in this place where we have some of the best-managed fisheries in the world, and it still created all these impacts,” Free said.

The Blob was the largest and longest-lasting marine heat wave on record. It might also have been an early glimpse of what’s to come. Fish farms in Chile, scallop operations in Australia, and snow crab pots in Alaska have already fallen victim to oceanic overheating. The economic toll from a single occurrence on fisheries and coastal economies can be as hefty as $3.1 billion. The northeastern Pacific Ocean has experienced several hot spells over the past decade — including the Blob 2.0 — and it’s still experiencing one. As a result, six of the last seven Dungeness crab seasons in California have been delayed. Scientists predict more fisheries will collapse in coming years as climate change — and the ongoing El Niño weather pattern warming the Pacific — spurs more marine heat waves 

“I’m really worried,” said William Cheung, director of the Institute of Oceans and Fisheries at the University of British Columbia. “This year we already know the temperature is crazy high.” 

As the planet warms, marine heat waves have grown more frequent and more severe. The world’s oceans have absorbed 90 percent of the heat trapped in the atmosphere by greenhouse gasses, and are as hot as humans have ever measured them. During a hotspot in late July, water off the southern tip of Florida reached 101 degrees Fahrenheit — toasty enough to fill a hot tub. 

“That’s the highest water temperature I’ve ever heard of in the ocean,” said Steve Murawski, a fisheries biologist at the University of South Florida who has studied oceans for 50 years. “Fish species in particular are great canaries in our collective coal mine.”

Marine heat waves can form in a number of ways, but in general they’re caused by changes in how the air and ocean currents move. When the wind weakens, the sea temperature tends to rise because warm surface water doesn’t evaporate as easily, and colder water doesn’t get churned up from the deep. 

Shifts beneath the surface can trigger heat waves, too. One appeared off the west coast of Australia in 2011 when a streak of warm water, some 100 miles wide and 3,000 miles long, surged south. It brought so much warmth from the tropics that ocean temperatures in the region rose almost 11 degrees Fahrenheit above normal. The extreme conditions stuck around for about three months, killing shellfish and forcing scallop and crab fisheries to close. To this day, the kelp forests, which provide crucial habitat for marine creatures like lobsters, haven’t recovered, said Alex Sen Gupta, an ocean and climate scientist at the University of New South Wales.

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As the sea grows warmer, marine heat waves are more likely to tip temperatures past the threshold at which coral, kelp, and other marine life can survive. In western Australia, heat waves as intense as the one in 2011 occur roughly once every 80 years. They could arrive as often as once a year by 2100 if countries continue pumping carbon dioxide and methane into the air at high levels. Researchers pegged the chances of the Blob having re-emerged as strongly as it did in the Pacific Ocean in 2019 at less than 1 percent if it weren’t for human-caused warming. 

How global warming alters the wind and ocean patterns that spawn marine heat waves remains an “open question,” said Mike Alexander, a climate scientist at the National Oceanic Atmospheric Administration. Yet he and Sen Gupta don’t doubt that planetary warming and rising ocean temperatures are making marine heat waves worse. 

Fish that prefer cold water, like cod and salmon, are particularly vulnerable to heat waves. Warm water forces them to work harder, which means they need more food to sustain themselves. At the same time, it can make prey less accessible — say, by keeping the zooplankton salmon feast upon from rising to the surface for an easy supper. 

The heat also can restrict Pacific cod spawning habitat. Amid extreme heat in the Gulf of Alaska, their numbers tanked between 2013 and 2017. The population struggled to recover, so in 2020 the federal government closed the commercial season for the first time. The fish hauled out of the Gulf of Alaska have accounted for as much as 18 percent of the Pacific cod caught around the world. “It’s kind of devastating,” longtime cod fisherman Frank Miles, based in Kodiak, Alaska, told NPR at the time. 

The cod harvest has since reopened, but other fisheries haven’t been as resilient. In 2021, Canada closed 60 percent of its commercial Pacific salmon harvests, which support an industry that employs more than 6,000 people in British Columbia. 

As many as 30 million sockeye salmon migrated up British Columbia’s Fraser River in 2010. A decade later, only 291,000 salmon returned. The fish are declining for a number of reasons, but scientists say extreme ocean heat is a major culprit. 

“We’re really seeing substantial declines in salmon productivity,” said Catherine Michielsens, chief of fisheries management science at the Pacific Salmon Commission. She said there’s a “real concern” that British Columbia is witnessing the end of its commercial salmon fisheries.

It’s easy to focus on the heat during a heat wave, but high temperatures aren’t the only threat to fisheries. These weather patterns can cause a cascade of ecosystem changes, from algal blooms to shifting whale feeding grounds, that can wreak havoc on the fishing industry. That’s what happened in late 2015, at the tail end of the Blob. California, Oregon, and Washington delayed their Dungeness crab seasons — one of the West Coast’s most valuable seafood harvests — because the warm water spurred the growth of toxic algae, which catapulted a neurotoxin called domoic acid up the food chain. The crabs were more or less fine, but anyone who ate one might have wound up in the emergency room vomiting, lost some short-term memories, or even died. 

When California finally opened its crab season after a four-month closure, West Coast fisherfolk had lost an estimated $97.5 million compared to the previous year. But the Blob added more trouble to the mix. The warm water pushed krill, humpback whales’ main grub, toward the coast and into crabbers’ territory. “There was this intense overlap between the Dungeness crab fishery and humpback whales that led to an enormous spike in humpback whale entanglements in crab-fishing gear,” Free said. 

California’s Dungeness harvest rebounded with a strong catch in late 2016 and 2017, but it continues to face closures and delays due to concerns about toxic algae and trapped whales — a stark contrast from the pre-Blob era, when there were very few closures, Free said. “It’s putting the fishery on sort of a precipice right now.”

The northeastern Pacific is not the only place where fisheries are feeling the heat. One place of particular concern is the Gulf of Maine — in the northwest Atlantic Ocean — which has experienced a marine heat wave every year since 2012, according to Kathy Mills, a fisheries ecologist at the Gulf of Maine Research Institute. 

The Gulf of Maine is like a sink with two faucets: one has cold water moving south from the Labrador Sea, the other has warm water from the tropics moving north along the Gulf Stream. But in recent years the Gulf Stream, a strong current that travels from the Caribbean up the East Coast and across the North Atlantic to Europe, has shifted northward, and the Labrador Current has gotten warmer, Mills said. “Instead of turning them on in the balance they used to be on, now we’re turning on the hot water more, and the cold water is not as cold as it used to be.” 

The result is that Maine lobsters, a bounty worth $725 million last year, have been growing faster and shedding their shells earlier. In the short term, the heat has been a boon for those who pluck them from the water, as it spurs growth and boosts lobster numbers. Business has been “booming,” Mills said. But if the trend continues, the critters might be forced to expend so much energy that they won’t be able consume enough food to reproduce or survive. 

“Now we’re getting to a point where the temperatures have been so warm for so long, and they are continuing to increase,” Mills said. “We might already be seeing signs that the population is turning off its growth trajectory because of temperature.” One of those signs is that lobster babies are becoming less prevalent. The heat appears to be a reason, among others, that lobster fisheries have already collapsed farther south, where the ocean is warmer, in southern New England.

There’s a silver lining, though: Lobsters that forage on cooler seabeds farther north, off the coast of Canada, might benefit from the heat; in fact, those populations have already been turning up in larger numbers. At the same time, “a whole suite” of species from warmer waters in the mid-Atlantic, such as longfin squid and black sea bass, both of which support multi-million-dollar commercial fisheries, have appeared a lot more frequently in the Gulf of Maine, where they used to be quite rare, said Mills. 

On the West Coast, a similar range shift is happening with California market squid — footlong, white-and-purple mollusks. (You may have tasted the mild meat of a market squid if you enjoy calamari.) Ever since the Blob, the squid have been seen as far north as Alaska, well beyond their usual habitat in the seas off Mexico and California. The heat wave has ended, but the squid are still hanging out up north. There is talk of opening a new fishery. 

“There are always going to be winners and losers,” Murawski said.

This story was originally published by Grist with the headline The ocean is shattering heat records. Here’s what that means for fisheries. on Aug 11, 2023.

Pittsburgh, in its founding, was blessed and cursed with two abundant natural resources: free-flowing rivers and a nearby coal seam. Their presence made the city’s 20th-century status as a coal-fired, steel-making powerhouse possible. It also threw so much toxic smoke in the air that the town was once described as “hell with the lid off.”

Though air quality laws strengthened over the decades, pollution in Pittsburgh and surrounding Allegheny County has remained high, ranking among the 25 worst metro areas in the United States for fine, easy-to-inhale particles known as PM2.5. Carbon pollution can often feel so big — borne on the air, causing ice caps to go black and melt. But it also causes problems much closer to home. Allegheny County’s inhabitants are among the top 1 percent in the nation for cancer risk, and the area is notorious for its high rates of asthma and heart issues, both of which, like the biggest emitters, are concentrated in low-income neighborhoods and communities of color. These kinds of health problems can often seem both mysterious in origin and inescapable for the people who live with them. However, the January 2016 closure of the Shenango Coke Works coal-processing plant provided an astonishing example of how quickly those same communities can recover from the most dire impacts of pollution.

Shenango was a coke oven — a facility that heats coal to around 2,000 degrees Fahrenheit to produce coke, which is in turn used to make steel. Such operations are famously nasty particle polluters, emitting not only carbon dioxide but also contaminants like benzene, arsenic, lead, and mercury. 

The research, led by the New York University-Langone School of Medicine, used medical records from area hospitals to determine emergency room visits and hospitalizations for heart ailments in the three years preceding and following the closure of the plant. They found an astonishing 42 percent drop in  weekly emergency cardiovascular admissions after 2016. That immediate drop was followed by a downward trend that continued for three years. The study also found corresponding steep drops in sulfur dioxide — as high as 90 percent near the facility and 50 percent at a monitoring station six miles away. Arsenic levels plummeted by two-thirds.

Study co-author George Thurston compared the sudden improvement to the benefits of quitting smoking. “Over time the body recovers,” he said. “Instead of at an individual level, you’re really looking at a community healing after the removal of that exposure.”

To Thurston, and study lead author Wuyue Yu, this research shows that cutting carbon emissions offers more than an abstract, long-term, far-ranging result. It can actually save lives, almost immediately.

The study was prompted by years of local agitation about the plant. Shenango closed under intense community scrutiny and had paid the county millions of dollars in fines for multiple air quality violations. 

For years, an organization called Allegheny County Clean Air Now, or ACCAN, fought to rein in ongoing emissions at the plant, bringing in the Environmental Protection Agency, the Allegheny County health department, and Carnegie Mellon University to monitor the plant’s pattern of violations and the health consequences for its neighbors. ACCAN members served as community scientists, collecting data and taking the results to local officials, company shareholder meetings, and U.S. Steel. Even steelworkers from the plant occasionally attended meetings, expressing concern about the situation. Now, says ACCAN member Thaddeus Popovich (who was told that there’s a 40 to 50 percent likelihood that his own triple-bypass heart surgery was prompted by living half a mile from Shenango), he and his peers feel “vindicated.”

After plant’s closure, members of ACCAN gathered and set to paper their memories of life before Shenango shut down. In the resulting collection, called Living Downwind, people describe living with fiery and sulfurous smells and mysterious ailments. Angelo Taranto, an active ACCAN member, lost his wife to a host of respiratory problems he’s sure were caused by Shenango’s billowing smoke. “These personal situations really energize people to want to do something,” he said. 

After the closure, Taranto said, ACCAN encouraged the Allegheny County health department to pull together some retrospective health studies. In 2018, Dr. Deborah Gentile documented a 41.6 percent drop in uncontrolled pediatric asthma two years following Shenango’s shuttering.

“What we were hearing from county officials was that they didn’t think the closure would be a boon to county health,” Taranto said. “We heard similar things from the company itself and we knew that wasn’t true, and we knew that we couldn’t let those types of statements remain unchallenged.”

There’s still a long way to go for the greater Pittsburgh area, though. Matt Mehalik, the director of the Breathe Project — which used its resources to support ACCAN and connect them to researchers —  points to similar facilities, such as the Clairton coke oven and the Mon Valley steel works, as contributors to major public health problems. Clairton, 10 times as large as Shenango ever was, sits near a low-income, majority-Black neighborhood, and community organizations have worked for years to hold the facility accountable to the harm it has caused. Environmental advocates are currently urging the EPA to revoke Clairton’s permit. The EPA has also proposed a stricter standard for toxic coke oven emissions, which could increase pressure on plants like Clairton.

Mehalik is excited about a potential transition to less coal-reliant forms of steelmaking as a long-term solution for Allegheny County. “We know that an investment in the right type of green steelmaking is needed if there is a future of steelmaking in the Mon Valley,” he said. “Perpetuation of a polluting facility that comes at the expense of our county is highly problematic.”

This story was originally published by Grist with the headline After a Pittsburgh coal processing plant closed, ER visits plummeted on Aug 11, 2023.

Over thousands of years, the Mississippi River wended its way through the lush and dense wetlands of the Barataria Basin in what’s now south-central Louisiana. As it flowed south on its way to the sea, the river continually poured sediment into the basin, gifting it with fresh, nutrient-rich river mud that replenished the land and prevented coastal erosion. But 20th-century innovations like dams and levees stopped the river’s natural systems. This, in combination with recent sea-level rise and the constant battering of supercharged hurricane seasons, means the sea now gnaws steadily at the bottom of the state, causing gradual but catastrophic land loss. Since 1932, the Barataria has lost 17 percent of its land. It’s predicted to lose another 200-plus square miles in the next 20 years. 

To combat this, Louisiana officials broke ground Thursday on an ambitious, $2.92 billion project to divert sediment from the Mississippi River into the basin, mimicking the natural processes of the river’s flow in an attempt to save the state’s disappearing coast. The initiative is the first step in Louisiana’s $50 billion Coastal Master Plan, funded in part by a lawsuit settlement from the devastating Deepwater Horizon oil spill of 2010. Though many laud the project, some worry it will harm existing wildlife in the basin, while taking a very long time to do its work.

The main event for the mid-Barataria Sediment Diversion Project will be “punching a hole in the levee” that prevents the Mississippi River from regularly overflowing its banks and changing course, said Bren Haase, the chair of the state’s Coastal Protection and Restoration Authority. The project involves installing a complex gate structure through the Mississippi River’s levee, allowing some water to flow into a channel, which will then empty out over the basin and wash into the sea, carrying mud, silt, and clay with it to create new land. It’ll take five years to build. Over 50 years, the diversion project should add 21 square miles of land to the basin, according to Haase. 

Supporters note the project will help restore a degraded ecosystem to some of its former glory. “There are large areas of open water where the marsh has just eroded and sunk away,” said Natalie Snider, associate vice president for the Environmental Defense Fund’s Climate Resilient Coasts and Watersheds program.

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Engineers factored sea-level rise projections of up to two and a half feet into the project’s design. But some scientists warn that sea-level rise is ultimately a wild card. There’s no knowing exactly how much, how or quickly, oceans will go up in the coming decades — and at some point, funding will likely run out for updates. For all the acres gained, they said, many will still be lost over time to the ravages of climate change. 

“It’s mitigation, not restoration,” said Rex Caffey, an associate professor of wetlands and coastal resources at Louisiana State University. “Slowing down the bleed.” 

The project has also been met with outcry from some of the people who make their living from the region’s fisheries. Louisiana has the most biorich fisheries  of any state, and some say the influx of freshwater from the project will decimate saltwater-loving stock in the basin, like oysters and shrimp.

This story was originally published by Grist with the headline Louisiana breaks ground on experimental project to rebuild lost wetlands on Aug 10, 2023.

Have you ever found yourself with a bunch of fabric — maybe old clothes, rags, socks, or tablecloths — that you just can’t find a use for, and don’t quite know what to do with? Well, don’t throw it in the trash, since 95% of all clothing, shoes, and other fabrics can be recycled in a textile recycling operation.

Why Is Textile Recycling Important? 

Globally, 92 million tonnes of textile waste is produced each year. Imagine: that’s a garbage truck’s-worth of textiles being thrown away every second. Americans alone throw away about 70 pounds of textiles each year, amounting to 17 million tons of annual waste, only 2.5 tons of which is recycled.

Textile waste isn’t just a matter of landfill space, but of social and environmental justice. With the rise of fast fashion in recent decades, clothing goes in and out of style faster than ever. Garments are made cheaply and quickly — often by exploited laborers —  and their poor quality means they won’t last long, either. In all, consumers buy about 60% more clothes than they did 15 years ago, and they’re only kept for half as long. Even when clothes are returned to retailers, they end up in landfills most of the time, since it’s less expensive than putting them back into circulation. Fast fashion alone is responsible for about 10% of all global carbon emissions, which is more than the emissions of all international flights and shipping combined. Furthermore, dying fabrics accounts for 20% of all water pollution. With so much fabric being produced, textile recycling can help give a piece of fabric — clothing or not — another life, and limit new fabrics from being produced.

What About Donating? 

Donating is certainly a viable option for suitable clothing that is still usable in its current form. However, clothing donation isn’t a silver bullet for our textile waste problem. According to the Council for Textile Recycling, charities that receive clothing donations will often ship a high percentage of it overseas. About 700,000 tons of used clothing gets shipped to other countries each year, and while these resources can be useful, there is also evidence that it harms local economies. For example, an imported secondhand clothing item can cost as much as 95% less than a clothing item produced in Kenya, which makes it hard for local businesses to compete. Goodwill, for one, is only able to sell about 30% of clothing donated in their thrift stores and through e-commerce. The remainder is sent to outlets, then sold in bulk, where a percentage is exported. Clothing that is unsuitable for wearing is also unsellable, but it might be recyclable.

How Does Textile Recycling Work?

When brought to a fabric recycler, individual textile items will be evaluated for their usefulness. Sometimes, they will be sold as clothing, or sold to be manufactured into other products. According to Secondary Materials and Recycled Textiles (SMART) Association, recycled fabrics are often used to make rags/wiping cloths that are needed in many industries, like construction, manufacturing, and custodial work. Or, the fabric is sold to recycling facilities to be dismantled. 

Different mechanical processes are used to recycle different kinds of fabric — especially natural vs. synthetic fabrics — so textiles are sorted by type (clothing, towels, etc.), type of fabric, and color. After being sorted, the fabrics are ready to be disassembled in one of two ways: mechanically or chemically. Since chemical processing is still an emerging and expensive method, mechanical processing is the primary mode of recycling. 

During mechanical processing, fabric is either shredded or pulled apart into its individual fibers — this works especially well for cotton and yarn. The machines tear at the fabric to break it down into its component fibers, which are then aligned in a process called “carding” to get them ready for reweaving. The fibers are respun into yarn that can be knitted or woven into new items. When a piece of fabric cannot be respun, it usually becomes filling, or “shoddy,” a product made from low-quality fabrics that’s used as insulation. This process doesn’t require any chemicals, which makes it advantageous, but shredding does impact the quality of the yarn as the fibers get shorter, which makes it harder to make high-quality garments. When respinning, virgin material is usually added to create a more high-quality fabric than if only the recycled fibers were used. 

Check the tags of your clothing, and you’ll probably see some that indicate that the garment was made with recycled polyester. Believe it or not, that likely means it was made from plastic water bottles. Synthetic fabrics that use polyester usually use blends of various materials, which makes them more difficult to recycle — so 95% of recycled polyester actually comes from recycled PET (polyethylene terephthalate) bottles. These bottles are sorted, shredded into flakes, cleaned, then melted to make new polyester fibers. 

How Do You Recycle Your Own Fabric? 

Now, what about that pile of old fabric you need to get rid of? 

First, check the condition of the items. In order to be recycled, they need to be completely clean and dry. Bacteria and moisture can contaminate an entire batch of recycling, leading to the entire bale being thrown away. 

There are a few options for recycling your unwanted fabric: 

1. Drop-off bins. Research recycling drop-offs in your area. Use Earth911’s free recycling finder to find nearby places to bring your items. These locations will usually be drop-off bins run by fabric recycling organizations, although sometimes they’ll feature local charities.
2. Local charities. Some charities will accept textile recycling, which they’ll then sell to generate revenue for their organization. Goodwill, Salvation Army, or other secondhand retailers will take suitable clothing to sell in their retail stores, but not usually other textiles. 
3. Private companies. Just like compost-collection services, private companies will come collect your textile waste for a fee, like CheckSammy and Retold. Always be sure to research a company before using their services to determine whether their recycling methods are legitimate. Some clothing companies will also offer to take your old clothing for free to be recycled, like Patagonia, Pact, and Girlfriend Collective, among many others.
4. Special events. Sustainability fairs, farmers markets, and city-run events might sponsor occasional free textile recycling drop-offs. Green Tree Textiles Recycling, for example, has booths at all of the New York City Down to Earth Farmers Markets to collect textile recycling. 

What Are the Difficulties With Textile Recycling?

Textile recycling isn’t perfect. Recycling technologies require consistent materials to work, and clothing products are variable. Dyes, finishes, and other chemicals require more steps and specialized processes, and impurities like buttons, zippers, and sequins need to be removed. Some garments also contain multiple different fabrics that need to be processed differently. The quality of fabric does suffer when disassembled, so virgin material usually needs to be incorporated into recycled products in order to make a high-quality garment. However, sometimes lower quality fabrics are “downcycled” and employed for other uses, like mattress stuffing. 

Emerging Technologies in Textile Recycling

Emerging technological solutions could make textile recycling more efficient and comprehensive. Re-polymerization — a type of chemical recycling — can break polyethylene terephthalate (PET) down to the molecular level, which is then “polymerized” to make new fibers. BlockTexx is also developing new technology to recycle blended fabrics made with a mixture of natural and synthetic fiber, which is notoriously difficult to recycle. 

The post What Is Textile Recycling? appeared first on EcoWatch.

Last month, the American Chemistry Council, a petrochemical industry trade group, sent out a newsletter highlighting a major new report on what it presented as a promising solution to the plastic pollution crisis: using “recycled” plastic in construction materials. At first blush, it might seem like a pretty good idea — shred discarded plastic into tiny pieces and you can reprocess it into everything from roads and bridges to railroad ties. Many test projects have been completed in recent years, with proponents touting them as a convenient way to divert plastic waste from landfills while also making infrastructure lighter, more rot-resistant, or, ostensibly, more durable.

“As our nation sets about rebuilding our infrastructure and restoring our resilience, plastic will play an outsized role,” the American Chemistry Council, or ACC, a petrochemical industry trade group, says on one of its websites.

But independent experts tell a much more complicated story, suggesting that most applications involving plastic waste in infrastructure are not ready for prime time. In recent years, several reports and literature reviews have highlighted the unknown health and environmental impacts of repurposing plastic into construction materials. They’ve also warned that post-consumer plastic isn’t desirable for use in many types of infrastructure — and that diverting plastic into construction is unlikely to make much of a dent in the massive tide of plastic waste that the developed world produces. To the contrary, adding used plastic to construction materials could even incentivize more plastic production.  

Take a closer look at the 407-page National Academies of Sciences report the ACC highlighted in its newsletter, for example, and you’ll find that it said there has been virtually “no significant research” in the United States to back claims about the benefits of using plastic in roads. Other construction applications face “high material and installation costs,” as well as “uncertainties about long-term performance and environmental impact.”

“There is opportunity to expand reuse of plastics in infrastructure applications,” the report concludes, “but it is not clear that this reuse pathway offers the greatest benefit to society.” 

Several recent studies have raised environmental concerns about microplastics, tiny fragments of plastics that could potentially slough off of plastic-infused infrastructure. Others say plastic chemicals could leach from plastic-infused construction materials into nearby waterways. (This already happens with materials that don’t have plastics in them.)

In general, experts say there’s been a near-total lack of research on the human health and environmental impacts of incorporating waste plastic into construction materials. A literature review published last month in the journal Frontiers in Built Environment, for example, looked at 100 recent studies on the topic and found that not one of them evaluated potential health costs of putting used plastic into roads, buildings, and other construction applications. Several studies addressed environmental implications, but mostly to highlight the potential to divert plastic waste from landfills.

According to Erica Cirino, lead author of the review and the communications manager for the nonprofit Plastic Pollution Coalition, it was these omissions that allowed the majority of the studies to portray putting discarded plastics into infrastructure as a “net positive.”

“There were a lot of aspects being overlooked,” Cirino told Grist, including the fact that several plastic-waste-in-infrastructure applications require the addition of new chemicals that could be harmful to human health. That’s on top of the 13,000 chemicals already found in plastics, one-fourth of which are known to have hazardous properties. 

Cirino also noted that a greater number of studies she reviewed were funded by chemical and plastic makers than by independent researchers, although this finding was not included in her final paper. 

The other major research gap, identified by Cirino’s team as well as other groups, is on the structural integrity of infrastructure incorporating plastic waste. Of the many uses for plastic waste that the National Academies looked at, including in asphalt, bike paths, lumber, marine pilings, railroad ties, utility poles, highway sound barriers, and bricks, only one — stormwater drainage pipes — has attracted significant demand from infrastructure owners. Other applications have deterred contractors because of the plastic-infused materials’ lower strength and stiffness, greater vulnerability to UV degradation, and propensity to crack. 

Most applications, though, have a very limited track record, having only been deployed in small-scale pilot projects or tested in the lab. “There’s just not a lot of information available and data that have been collected,” said David Dzombak, a professor emeritus of civil and environmental engineering at Carnegie Mellon University and chair of the committee that wrote the National Academies report. “The studies have been short-term and have limited scope in the questions they’re trying to answer.”

Even in a scenario where it was proven viable to put plastic waste in infrastructure, Dzombak said it isn’t clear this would be a significant sink for the more than 30 million metric tons of plastic waste that the U.S. generates each year. First, project developers tend to be fussy with the plastic they use: If they’re going to incorporate it into infrastructure, it usually has to be clean and high-quality polyethylene, not just whatever scraps of mixed plastic waste can be scraped from the bottom of consumers’ recycling bins. 

Infrastructure “is not just a dumping ground for plastic waste,” Dzombak said. In fact, he said demand is greater for post-industrial plastic scraps than for post-consumer plastic waste, contrary to the notion promoted by industry groups that roads and other infrastructure are commonly being made from discarded diapers, plastic bags, and other low-quality plastic trash. Such projects exist but are considered anomalous, and their performance and environmental impacts are poorly understood.

Second, the limited research that’s out there suggests that plastic waste can only make up a small fraction of most infrastructure materials. Asphalt pavement, for example — perhaps the most hyped-up kind of plastic infrastructure — can only accommodate a maximum of 0.5 percent waste plastic by dry weight, according to the National Academies’ literature review. The group’s “best-case scenario,” in which discarded plastic completely replaces virgin plastic in all of the United States’ sales of plastics-modified asphalt binder, would consume only 2.4 percent of the country’s trashed polyethylene every year, and an even smaller percentage of its total plastic waste generation.

“That’s not negligible, but it’s not going to be a game-changer,” Dzombak said. Besides, he added, there’s actually considerable demand for the kind of high-quality waste plastics that can be used in infrastructure. Rather than diverting this plastic from landfills, putting it in construction materials might divert it from other second-use applications like carpeting and clothing.

The ACC did not respond to Grist’s request for comment in time for publication.

Looking at the bigger picture, many environmental advocates are concerned about the way proponents talk about waste plastics in infrastructure as a “recycling” solution that contributes to a “circular economy.” Even if infrastructure applications do divert plastic from landfills, Cirino said, they’re just a stopping-over point. Because most plastics are nonrecyclable by nature — especially those that are mixed with other materials, since it’s so difficult to separate and process them back into the same products —  plastics in infrastructure are likely to end up in a landfill at the end of their life, necessitating a continued supply of waste plastic. Paradoxically, for some construction materials that are normally recyclable, such as asphalt, putting discarded plastic into them may make it so they can no longer be recycled.

Putting discarded plastic into infrastructure “can create new markets for more plastic waste, which in turn means more plastic production,” Cirino said. The system “is not circular and cannot be circular.” Her review paper said upstream strategies for addressing plastic pollution — like limiting plastic production — are “clearly favorable” to approaches that merely manage waste.

To be sure, many experts agree there are legitimate uses for plastics in infrastructure — compared to other materials, plastics may be lighter, more resistant to corrosion, and more malleable. The nonprofit Alliance for Sustainable Building Products, based in the U.K., says that as long as construction involves plastic, it might as well be “recycled” plastic, although it notes that plastics are generally overused in the construction industry. 

Dzombak, with the National Academies, said there is still potential for “circularity” in some cases, like with stormwater drainage pipes made from discarded plastic that could be recycled into new pipes. He said the question of whether to reduce plastic production was beyond the scope of the National Academies’ recent report and instead urged federal agencies to work together on an improved recycling strategy, including better collection and processing of discarded plastic. 

Overall, however, Dzombak, Cirino, and others say more research is needed to substantiate the plastic industry’s enthusiastic claims about the supposed promise of putting waste plastic in infrastructure — especially research on the idea’s environmental and health implications. Such research should examine the full life-cycle impacts of plastic production and disposal, Cirino said, and draw from what we already know about plastics’ risks.

“There is already a huge existing amount of information about the ecological, health, and social costs of plastic,” she said. “To really consider the full impacts, we need to dive even deeper.”

This story was originally published by Grist with the headline Using ‘recycled plastic’ in construction materials may not be a great idea after all on Aug 10, 2023.