Ode al sacchetto di plastica

Non è mia ma di Katherine Mangu-Ward, io la trovo solo convincente.

Cose più spesse di un sacchetto di plastica…

… A strand of hair. A coat of paint. A human cornea…

Per dire, il sacchetto di plastica è un miracolo della tecnologia umana…

… Despite weighing less than 5 grams, one bag can hold 17 pounds, well over 1,000 times its own weight…

Economico e funzionale: cosa vuoi di più dalla vita?

Eppure, questa meraviglia è diventata il bersaglio prediletto dell’ambientalista d’assalto. Ovunque è proibito o tassato.

L’accusa:

… coastal areas blame the wispy totes for everything from asphyxiated sea turtles to melting glaciers, while inland banners decry the bags’ role in urban landscape pollution and thoughtless consumerism…

Ma si tratta di accuse dubbie: il sospetto è che attaccare il sacchetto di plastica sia un atto simbolico in sfregio al consumismo.

In realtà potremmo considerare il sacchetto di plastica come…

one of the most efficient, resource-saving inventions of the 20th century…

Facciamo un po’di storia: prima dell’ottocento i mezzi per trasportare gli acquisti al dettaglio erano interamente a cura dell’acquirente…

… baskets for the little stuff and wheeled carts for the bigger… scraps of canvas or other durable fabric…

Inconvenienti: scomodità, germi e necessità di lavaggi frequenti…

… This was back when the germ theory of disease was yet to be broadly accepted, and there were not yet Laundromats on every street corner…

Poi la carta cominciò a diventare conveniente dominando la scena per un secolo…

… The paper bag was invented in the 1850s, but it wasn’t until the 1870s that a factory girl named Margaret Knight cobbled together a machine that cut, folded, and glued flat-bottomed paper receptacles….

Pechmann fu il primo eroe della plastica…

… German chemist Hans von Pechmann was messing around with methane and ether in a lab in 1898 when he happened to notice a waxy precipitate called polymethylene…

Seguito da Du Pont

… 30 years would pass before DuPont chemists stumbled upon a similar compound, polyethylene. This time, the British figured out they could use it to insulate radar cables, which is where the substance served its war duty…

E infine da Ziegler…

… In 1953, Karl Ziegler of the Kaiser Wilhelm Institute (later re-christened the Max Planck Institute, for obvious reasons) and Erhard Holzkamp invented high-density polyethylene (HDPE) and soon after figured out how to use it to make pipes…

Poi arrivò Thulin Sfen, il vero protagonista di questa storia…

… But Gustaf Thulin Sten is the real hero (or villain, depending on your point of view) of our tale. An employee of the Swedish company Celloplast, Sten was the person who had the inspiration to punch holes into the side of super-thin tubes of HDPE, thus creating the ubiquitous, filmy “T-shirt bags” we know and love (to ban) today…

Nel 1985 la plastica era più conveniente della carta dell’ 11,5%.

La conservazione delle foreste era affare importante negli anni ottanta, ma poi subentrò la fissa per il global warming: carta o plastica? Da sempre l’imbarazzo ambientalista è stato grande…

… Forest conservation was a big deal in the ’80s, a point in favor of plastic. But fossil fuels were a no-no, so maybe paper was better?…

Oggi, sacchetto di plastica uguale consumismo…

… In 2010, Guinness World Records named plastic bags the most ubiquitous consumer item in the world…

Cominciò la serie delle proibizioni a raffica…

… South Africans refer to bags snagged in bushes as their “national flower.” In Washington, D.C., concern about used plastic bags finding their way down storm drains, through the Anacostia River, and into the Chesapeake Bay was the primary justification for the capital city’s 5-cent bag tax in 2010, under the slogan “Skip the Bag, Save the River.”…

Trattiamo l’accusa di essere un rifiuto onnipresente, specie su spiagge e fiumi. Ebbene, il sacchetto è un rifiuto forse più visibile di altri ma in realtà molto meno invasivo di quel che si pensa comunemente …

… In 2006, the California Coastal Commission claimed that plastic bags make up 3.8 percent of beach litter, and a few years later the California Ocean Protection Council upped the ante to 8 percent of all coastal trash…

3,8%!?…

… But the definitive American litter study— yep, such a thing exists— reports much lower figures. The 2009 Keep America Beautiful Survey, run by Steven Stein of Environmental Resources Planning, shows that all plastic bags, of which plastic retail bags are only a subset, are just 0.6 percent of visible litter nationwide…

0,6%!!

Constatiamo poi con rammarico quanto  la metodologia dei primi studi fosse a dir poco dubbia…

… And those California data? They come from the International Coastal Commission (ICC), which the California Coastal Commission notes relies on information “collected by volunteers on one day each year, and is not a scientific assessment.”…

Nei fiumi i sacchetti sono almeno al terzo posto come presenza…

… only the third-largest contributor to litter in the river, after food wrappers and bottles and cans…

Veniamo ora all’accusa di minacciare la vita marina.

Ecco un esempio sintomatico di allarmismo

… The Blue Ocean Society for Marine Conservation is just one organization among many that claim that more than 1 million birds and 100,000 marine mammals and sea turtles die each year from eating or getting entangled in plastic…

Le fonti di certe dicerie…

… source this figure back to a study funded by the Canadian government that tracked loss of marine animals in Newfoundland as a result of incidental catch and entanglement in fishing gear from 1981 to 1984. Importantly, this three-decade-old study had nothing to do with plastic bags at all…

La goffa retromarcia di Greenpeace

… As David Santillo, a senior biologist with Greenpeace, told The Times of London, “It’s very unlikely that many animals are killed by plastic bags. The evidence shows just the opposite. We are not going to solve the problem of waste by focusing on plastic bags. With larger mammals it’s fishing gear that’s the big problem. On a global basis plastic bags aren’t an issue.”…

E sul fronte del global warming? Il sacchetto di plastica è davvero la minaccia di cui si dice? Per saperlo bisognerebbe calcolarne l’ “impronta ecologica”…

… A 2011 study from the U.K.’ s Environmental Agency attempted to quantify the emissions footprint both of plastic bags and of their substitutes…

Quanti riutilizzi richiedono i succedanei del sacchetto di plastica per compensare la sua impronta ecologica?…

… Holding the typical HDPE grocery bag up as the standard, researchers found that the common reusable non-woven polypropylene bag— the ubiquitous crinkly plastic tote, typically made with oil— had to be used at least 11 times to hold its own against an HDPE grocery bag. Cotton bags had to be used an amazing 131 times to do the same…

11 e 131. Non male. Ma studi del genere restano comunque deficitari: assumono che i sacchetti non vengano mai riutilizzati e che le borse non vengano mai lavate…

… U.K. Environmental Agency figures assume the HDPE bag is not being reused. Nor do they account for the energy and materials needed to regularly wash the reusable bags in hot soapy water…

In realtà, il riutilizzo del sacchetto è la norma…

… About 65 percent of Americans report that they repurpose their grocery bags for garbage. By contrast, a survey by the marketing research firm Edelman Berland found that consumers reported forgetting their reusable bags on 40 percent of grocery trips and opted for plastic or paper instead. Prior to the movement to ban plastic bags, many American homes had a nook, cranny, or drawer that functioned as a kind of grocery-sack clown car. It seemed that whatever the size of the container, an infinite number of bags could be stuffed inside…

Altra accusa: troppi sacchetti in giro, nessuno ricicla…

… 100 billion plastic bags that are thrown away in the U.S. every year.”…

Nessuno sa da dove arrivino questi numeri. I numeri da prendere più seriamente sono altri…

… In 2010, according to the U.S. Environmental Protection Agency, Americans threw away 690,000 tons of HDPE bags. Of those, approximately 30,000 tons were recycled. That means a total of 660,000 tons were discarded, mostly into landfills (approximately 82 percent of non-recovered municipal solid waste goes to landfill; 18 percent is incinerated)…

Ma soprattutto: il riciclo delle alternative al sacchetto non è certo più massiccio…

… That same year, Americans also chucked almost exactly the same amount of “reusable” polypropylene bags (680,000 tons), of which zero were recovered… reusable bags actually constituted a slightly higher proportion of all bags going to landfills….

Ma il mancato riciclo sembra un peccato veniale: riciclare non conviene, è un mero spreco di risorse…

… In April, NPR’s Planet Money reported on the economics of plastic recycling, and noted that while recycled plastic from bags and sacks was once a profitable industry, times have changed. The prices of oil and gas have fallen, which means it is cheaper to just make new bags rather than undertake the laborious process of recycling the old ones. As Tom Outerbridge, who runs a Brooklyn recycling center called Sims, explained, “We can’t afford to put a lot of time and money into trying to recycle it” if no one’s buying the final product….

Il ritorno delle borse riutilizzabili è in realtà un ritorno alla sporcizia della nonna…

… reminiscent of the sub-hygienic reality faced by my great-great-grandmother,…

Il modo migliore per beccarsi una diarrea

… Put a leaky package of chicken in your cloth or plastic tote. Then go home, empty the bag, crumple it up, and toss it in the trunk of your car to fester. A week later, you go shopping again and throw some veggies you’re planning to eat raw into the same bag. Cue diarrhea….

Presenze inquietanti nella metà delle borse riutilizzabili…

… A 2011 survey published in the journal Food Protection Trends found coliform bacteria in fully half of the reusable shopping bags tested…

Altre ricerche sulla scarsa igiene delle borse alternative al sacchetto di plastica…

… The same 2014 Edelman Berland study that found consumers frequently forgot their bags also unearthed the fact that only 18 percent of shoppers reported cleaning their bags “once a week or more.” An article in the Journal of Infectious Diseases traced a 2010 outbreak of norovirus to nine members of an Oregon soccer team who had touched or eaten food stored in a contaminated reusable bag…

Conclusione

… technology behind plastic grocery bags is so useful it won a Nobel Prize… Employing an unimaginably small amount of base material… Far from being the environmental threat activists make them out to be, plastic bags are not particularly to blame for clogged sewers, choked rivers, asphyxiated sea animals, or global warming. Instead, they are likely our best bet for carrying all of our junk in a responsible manner….

cello

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