Tag Archives: microplastics

What the Naked Eye Can’t See: Nanoplastics in Food and Sea

Smaller plastic particles are especially dangerous, because they are easily ingested and can enter organs and body fluids of organisms and thus propagate up the food chain. The fact that these particles are also co-contaminated with various chemicals and other pollutants makes accurate assessments of the effects and toxicity of plastic pollution challenging. A group of scientists led by the IAEA has recently published a comprehensive review on the effects on fish of ‘virgin’ micro- and nano-plastics – tiny plastic particles such as resin pellets used in plastics manufacturing. The review, published in the journal Environmental Science and Technology in March 2020, revealed that in 32% of all studies assessed, such virgin plastic particles were indeed affecting biological functions in fish, such as their behavior and neurological functions, as well as their metabolism, intestinal permeability and intestinal microbiome diversity.

Plastic particles below 5 mm in length are called microplastics. The smaller ones, with a size equal to or less than 100 nm (1/10 000 mm) are called nanoplastics. They are so tiny that one cannot see them with naked eye or even with an ordinary optical microscope.

According to the UN Environment Programme, 8 million tonnes of plastic end up the world’s oceans every year, often carried there by rivers. If the trend continues, by 2050 our oceans could contain more plastic than fish Microplastic particles are accidentally consumed by marine organisms, which are then consumed by predator fish. Nanoplastic particles are even more toxic to living organisms as they are more likely to be absorbed through the walls of digestive tracts and thereby transported into the tissues and organs. Consequently, such plastic particles can interfere with various physiological processes, from neurotransmission to oxidative stress and immunity levels of freshwater and marine organisms.

Jennet Orayeva, New Research on the Possible Effects of Micro-and Nano-plastics on Marine Animals

Plastic Bags Back in Vogue: Blame COVID or Plastics Industry?

Plastic bags may make a temporary comback in some places because of COVID-19.
In a setback, albeit temporary, for efforts to combat plastic waste, many state and local governments have suspended plastic bag bans and are prohibiting the use of reusable bags to stem the spread of COVID-19. The plastics industry is pushing for such measures, causing environmentalists to cry foul. San Francisco, which has been at the forefront of single-use plastics restrictions, issued an order “not permitting customers to bring their own bags, mugs, or other reusable items from home” as a measure “to prevent unnecessary contact.” Maine is delaying enforcement of its plastic bag ban to Jan. 15, 2021, after originally planning to roll it out on April 22—Earth Day….

The plastics industry has been advocating for such measures. In recent weeks, Bag The Ban, an initiative sponsored by the American Recyclable Plastic Bag Alliance, has endorsed editorials in newspapers such as the Boston Herald and the New Hampshire Union Leader advocating use of plastic bags to protect grocery workers from COVID-19.

Writing to the US Department of Health and Human Services, the Plastics Industry Association made a similar point. “Single-use plastic products are the most sanitary choice when it comes to many applications.” The association cited research on reusable bags, including a 2011 study from Loma Linda University and the University of Arizona that tested bags from shoppers selected randomly at the grocery store and found bacteria such as E. coli on 8% of them. It also pointed to a 2012 outbreak of norovirus in Oregon linked to use of a reusable food bag and cited a 2019 study from Portugal that found bacteria in bags.

Alexander H. Tullo, Plastic bag bans rolled back for COVID-19, Apr. 7, 2020

Genes that Atttack Plastic

A common fixture in refrigerators, furniture and footwear, polyurethane plastic is pretty much always in high demand. Humans worldwide cycle through millions of tons of the durable substance each year, sending the bulk of what’s not recycled to garbage dumps, where it leaks toxic chemicals into the environment as it very slowly breaks down. At least one of Earth’s organisms sees the stuff as a boon: a bacterial strain called Pseudomonas sp.TDA1. This polyurethane-munching microbe seems to thrive in waste dump sites. Studying the Pseudomonas strain and the chemical strategies it deploys could someday help researchers put a small dent in the world’s plastic problem, which has cumulatively saddled the planet with more than 8 billion tons of slow-degrading synthetic material.

Pseudomonas sp. TDA1 is one of only a few microbes known to be tolerant to polyurethane plastic’s typically toxic properties. What’s more, the bacteria doesn’t just withstand the plastic’s harsh ingredients: it uses some of them as a food source… But while the bacterium can metabolize a subset of the chemicals in polyurethane plastic, it doesn’t seem able to break down these products completely. In-depth studies of Pseudomonas sp. TDA1 will reveal the genes crucial to these plastic-attacking abilities. Understanding how these genes and their products work could help scientists engineer synthetic approaches to tackling plastic in the future.

Excerpts from Katherine J. Wu, Scientists Discover Plastic-Munching Microbe in Waste Site, SMITHSONIANMAG.COM, Mar. 31, 2020

Sunlight Can Make Plastics Disappear

Numerous international governmental agencies that steer policy assume that polystyrene, a sort of plastic  persists in the environment for millennia. 

Styrofoam Cup

In their research paper published in the Journal of  Environmental Science and Technology Letters, scientists show the  that polystyrene is completely photochemically oxidized to carbon dioxide and partially photochemically oxidized to dissolved organic carbon. Lifetimes of complete and partial photochemical oxidation are estimated to occur on centennial and decadal time scales, respectively. These lifetimes are orders of magnitude faster than biological respiration of polystyrene and thus challenge the prevailing assumption that polystyrene persists in the environment for millennia. 

Excerpt from Collin P. Ward et al, Sunlight Converts Polystyrene to Carbon Dioxide and Dissolved Organic Carbon, Journal of Environmental Science and Technology Letters, October 10, 2019

From Streets into Drains into Seas: Cigarette Butts

Cigarette butts, the most littered items in the world, are posing an intractable trash problem for regulators and tobacco companies: Throwing them on the ground is a firmly entrenched habit for many smokers.  Regulators are taking a tougher stance on cigarette filter pollution amid concerns about the environmental impact of single-use plastic. Butts for decades have been made from cellulose acetate, a form of plastic, which takes years to break down. Studies show that butts—which often wash from sidewalks into drains and then waterways—can be toxic to fish.

About 65% of cigarettes smoked in the U.S. are littered, according to Keep America Beautiful, a nonprofit whose cigarette litter prevention program is funded by the tobacco industry.  “That whole habit is so ingrained it becomes part of the ritual of taking the cigarette out of the pack, lighting it, smoking it, putting it on the ground,” said Christopher Proctor, chief scientific officer at British American Tobacco (BAT), whose cigarette brands include Kent, Newport and Camel. “Changing ingrained behavior is a really difficult thing to do.”

The European Union in May adopted new rules under which members must pass laws within two years requiring tobacco companies to fund the cleanup of filter litter as part of a broader crackdown on single-use plastics. A bill proposing banning filters has made its way through the California Senate and will be heard by the lower house next year.  In response, BAT and Japan Tobacco Inc. are testing biodegradable filters, while Philip Morris International Inc. is assessing the appetite for portable ashtrays. Companies also are tapping behavioral psychologists to understand what propels smokers to litter, hoping to forestall stricter regulation…

he World Health Organization says that when filters do break down they leach out some of the 7,000 chemicals contained in cigarettes, many of which are environmentally toxic.

Excerpts from Saabira Chaudhuri, The World’s Most Littered Item Comes Under Fire, WSJ, July 31, 2019

When Plastic Reached the Himalayas: India’s War on Single-Use Plastics

The daily plastic waste generated by the average Indian—while much lower than the average American—climbed 69% between 2015 and 2018, according to government estimates. Across the country, dumps are overflowing and drains are clogging with plastic, while cows—considered sacred—are getting sick after eating packaging….To get a grip, India has instituted some of the world’s strictest rules on single-use plastic, forcing companies to collect packaging that is often left as litter.
 

Nonrecyclable packaging is a problem globally, but particularly acute in countries with poor waste management. Many Indian households lack regular collection services so they burn trash or dump it on the side of the road. Much of the waste ends up in waterways. Of plastic found in the world’s oceans, 90% is traced to 10 rivers, according to a 2017 study published in the journal Environmental Science & Technology. Eight of the rivers are in Asia and two flow through India.

Single-Serve Pouches

In emerging markets, products like shampoo and detergent are often sold in single-serve pouches similar to the ketchup packets that come with an order of fries. The resilient “multilayer” pouches protect against extreme temperatures and contamination, and, most important, are affordable for poor consumers. Single-serve packets make up over 80% of shampoo sales in India, Indonesia and the Philippines, according to Euromonitor….This type of packaging combines different types of plastic with materials like aluminum. That makes it nonrecyclable and of no interest to India’s waste pickers who trawl through trash looking for recyclables to sell.  Three years ago, India’s government said it would ban multilayer packaging by 2018, setting off alarm bells through the industry…

A consortium—including Nestlé, Pepsi and Mentos-maker Perfetti Van Melle SpA—tried for months to develop a recyclable alternative. After little success, they decided on a different approach.  Through street plays and workshops, the companies trained 1,500 waste pickers across eight cities to identify and collect multilayer packaging, paying them for what they brought in.  The pilot program amassed 680 metric tons of material in three months. In March 2018, New Delhi changed the law to allow the sale of multilayer packaging. The caveat is that companies must collect back the equivalent volume of what they sell and find other uses for it, like sending it to cement plants as fuel…

Despite such efforts, some government officials have accused companies of moving too slowly. E. Ravendiran of the Maharashtra Pollution Control Board says companies only swung into action after being threatened with bans or having to pay a deposit on multilayer packaging sold. Executives say the target of collecting 100% of multilayer plastic by 2020 is unrealistic and that details on how the rule will be implemented are scarce.

Hassan, a former waste picker who manages a small team of waste collectors in Bangalore, says pickers aren’t financially motivated to bend down hundreds of times to collect a kilogram of multilayer plastic from piles of mixed waste or just off the street. Saahas pays him 27 rupees (around 39 U.S. cents) for one kilogram of plastic bottles, compared with just 4 rupees for one kilogram of multilayer packaging, which is much harder to collect.

Excerpts,  Saabira Chaudhu India Saddles Consumer-Goods Makers With Fixing Plastic Trash Problem, WSJ, July 5, 2019

Melted Plastic on the Shores: Madeira Island

‘Plasticrusts’ are see on the surface of rocks in Madeira island, Portugal. Researchers say they may have identified a new kind of plastic pollution in the sea, and they’re calling it “plasticrust.” Scientists working on Madeira, a volcanic Portuguese island off northwest Africa, have found small patches of what look like melted plastic encrusted on rocks along the shoreline. 

Excerpts from Scientists on Madeira see new ‘plasticrust’ sea pollution, Associated Press,
June 25, 2019