from the world's big
House plants do not purify the air, study shows
Beautiful? Yes. Air purifiers? Not so fast.
- A new meta-analysis at Drexel University shows that house plants are not effective for purifying the air of toxins.
- A 1989 NASA report that claimed indoor plants are purifying was not conducted in realistic living conditions.
- Indoor plants have positive effects on our mental health, just not in regards to air quality.
There are a lot of strange ideas floating around, especially when it comes to purification. Juice cleanses are supposed to purify your body. (They don't.) Colonics are wonderful for clearing toxins from your intestines. (Highly questionable.) The "essence" of an ingredient is a healing agent. (Lol.) The recitation of a mantra purifies the soul. (Impossible to prove or disprove, as is the notion of a soul.)
One theory that's on solid footing is the notion that house plants purify the air. Or is it? Recently, a study appeared in the Journal of Exposure Science & Environmental Epidemiology that puts that long-held myth into question.
In this case there is precedent. Study authors Bryan E. Cummings and Michael S. Waring from the Department of Civil, Architectural and Environmental Engineering at Drexel University write that potted plants have previously been shown to remove airborne volatile organic compounds (VOC) in sealed chambers. Extrapolate by placing plants around your apartment or house and you end up with a natural air purification system.
This idea was first floated in a 1989 report included in the NASA Clean Air Study. Researchers tested plants, such as ficus and peace lilies, to see if they could cleanse the air of three VOCs: benzene, formaldehyde, and trichloroethylene. After a 24-hour period, the team noted that between 10-70 percent were removed. Plant stores found a new advertising slogan.
The problem, Cummings and Warring note, is that the chambers were a cubic meter in size. They were also sealed, unlike the buildings we inhabit. Scouring over 196 experiments in their meta-analysis, they conclude that even at their best, plants deliver less than 1 percent of toxin removal that an air purifier accomplishes.
Jill Valley-Orlando organizes houseplants from a recent shipment in the greenhouse at Broadway Gardens on Wednesday, January 16, 2019.
Staff photo by Brianna Soukup/Portland Portland Press Herald via Getty Images
This matters as humans spend, on average, 90 percent of their time indoors. On top of this, Cummings and Waring note that, "Much, though not all, of indoor pollution is sourced directly from the indoor environment itself." Air fresheners, paints, glues, printers, and permanent markers (among other manufactured products) add VOCs into the air we breathe. Poor indoor air quality has been implicated in a variety of health risks, including respiratory diseases and headaches.
All is not lost, however. As the authors note, "Indoor plants, by helping to create a more biophilic indoor environment, may have a positive impact on occupant well-being." However, they write that indoor plants have a tendency to raise humidity levels. Some even produce VOCs of their own.
Nothing is ever a clear-cut as it seems. This is not a call for removing house plants. They make a lovely addition to home and office environments. We just have to recognize that their appeal is aesthetic and emotional, not as agents in our long quest for purity.
- Every Breath You Take. The Hidden Danger of the Aeolian Plankton ... ›
- Plants have awareness and intelligence, argue scientists - Big Think ›
- Genetically-modified houseplant removes carcinogens from air - Big ... ›
Innovation in manufacturing has crawled since the 1950s. That's about to speed up.
Richard Feynman once asked a silly question. Two MIT students just answered it.
Here's a fun experiment to try. Go to your pantry and see if you have a box of spaghetti. If you do, take out a noodle. Grab both ends of it and bend it until it breaks in half. How many pieces did it break into? If you got two large pieces and at least one small piece you're not alone.
But science loves a good challenge<p>The mystery remained unsolved until 2005, when French scientists <a href="http://www.lmm.jussieu.fr/~audoly/" target="_blank">Basile Audoly</a> and <a href="http://www.lmm.jussieu.fr/~neukirch/" target="_blank">Sebastien Neukirch </a>won an <a href="https://www.improbable.com/ig/" target="_blank">Ig Nobel Prize</a>, an award given to scientists for real work which is of a less serious nature than the discoveries that win Nobel prizes, for finally determining why this happens. <a href="http://www.lmm.jussieu.fr/spaghetti/audoly_neukirch_fragmentation.pdf" target="_blank">Their paper describing the effect is wonderfully funny to read</a>, as it takes such a banal issue so seriously. </p><p>They demonstrated that when a rod is bent past a certain point, such as when spaghetti is snapped in half by bending it at the ends, a "snapback effect" is created. This causes energy to reverberate from the initial break to other parts of the rod, often leading to a second break elsewhere.</p><p>While this settled the issue of <em>why </em>spaghetti noodles break into three or more pieces, it didn't establish if they always had to break this way. The question of if the snapback could be regulated remained unsettled.</p>
Physicists, being themselves, immediately wanted to try and break pasta into two pieces using this info<p><a href="https://roheiss.wordpress.com/fun/" target="_blank">Ronald Heisser</a> and <a href="https://math.mit.edu/directory/profile.php?pid=1787" target="_blank">Vishal Patil</a>, two graduate students currently at Cornell and MIT respectively, read about Feynman's night of noodle snapping in class and were inspired to try and find what could be done to make sure the pasta always broke in two.</p><p><a href="http://news.mit.edu/2018/mit-mathematicians-solve-age-old-spaghetti-mystery-0813" target="_blank">By placing the noodles in a special machine</a> built for the task and recording the bending with a high-powered camera, the young scientists were able to observe in extreme detail exactly what each change in their snapping method did to the pasta. After breaking more than 500 noodles, they found the solution.</p>
The apparatus the MIT researchers built specifically for the task of snapping hundreds of spaghetti sticks.
(Courtesy of the researchers)
What possible application could this have?<p>The snapback effect is not limited to uncooked pasta noodles and can be applied to rods of all sorts. The discovery of how to cleanly break them in two could be applied to future engineering projects.</p><p>Likewise, knowing how things fragment and fail is always handy to know when you're trying to build things. Carbon Nanotubes, <a href="https://bigthink.com/ideafeed/carbon-nanotube-space-elevator" target="_self">super strong cylinders often hailed as the building material of the future</a>, are also rods which can be better understood thanks to this odd experiment.</p><p>Sometimes big discoveries can be inspired by silly questions. If it hadn't been for Richard Feynman bending noodles seventy years ago, we wouldn't know what we know now about how energy is dispersed through rods and how to control their fracturing. While not all silly questions will lead to such a significant discovery, they can all help us learn.</p>
Join Pulitzer Prize-winning reporter and best-selling author Charles Duhigg as he interviews Victoria Montgomery Brown, co-founder and CEO of Big Think.
Women today are founding more businesses than ever. In 2018, they made up 40% of new entrepreneurs, yet in that same year, they received just 2.2% of all venture capital investment. The playing field is off-balance. So what can women do?
In a recent study, researchers examined how Christian nationalism is affecting the U.S. response to the COVID-19 pandemic.
- A new study used survey data to examine the interplay between Christian nationalism and incautious behaviors during the COVID-19 pandemic.
- The researchers defined Christian nationalism as "an ideology that idealizes and advocates a fusion of American civic life with a particular type of Christian identity and culture."
- The results showed that Christian nationalism was the leading predictor that Americans engaged in incautious behavior.
A pastor at the chapel of the St. Josef Hospital on April 1, 2020 in Bochum, German
Sascha Schuermann/Getty Images<p>Christian nationalists, in general, believe the U.S. and God's will are tied together, and they want the government to embody conservative Christian values and symbols. As such, they also believe the nation's fate depends on how closely it adheres to Christianity.</p><p style="margin-left: 20px;">"Unsurprisingly then, in the midst of the COVID‐19 pandemic, conservative pastors prophesied God's protection over the nation, citing America's righteous support for President Trump and the prolife agenda," the researchers write.</p><p style="margin-left: 20px;">"Correspondingly, the link between Christian nationalism and God's influence on how COVID‐19 impacts America can be seen in proclamations about God's divine judgment for its immorality―with the logic being that God is using the pandemic to draw wayward America <em>back </em>to himself, which assumes the two belong together."</p><p>The logical conclusion to this kind of thinking: America can save itself not through cautionary measures, like mask-wearing, but through devotion to God. What's more, it stands to reason that Christian nationalists are less likely to trust the media and scientists, given that these sources are generally not concerned with promoting a conservative, religious view of the world.</p><p>(The researchers note that they're unaware of any research directly linking Christian nationalism to distrust of media sources, but that they're almost certain the two are connected.)</p>
Predicted values of Americans' frequency of incautious behaviors during the COVID‐19 pandemic across values of Christian nationalism
Perry et al.<p>In the new study, the researchers examined three waves of results from the Public and Discourse Ethics Survey. One wave of the survey was issued in May, and it asked respondents to rate how often they engaged in both incautious and precautionary behaviors.</p><p>Incautious behaviors included things like "ate inside a restaurant" and "went shopping for nonessential items," while precautionary behaviors included "washed my hands more often than typical" and "wore a mask in public."</p><p>To measure Christian nationalism, the researchers asked respondents to rate how strongly they agree with statements like "the federal government should advocate Christian values" and "the success of the United States is part of God's plan."</p><p>The results suggest that, compared to other groups, Christian nationalists are far less likely to wear masks, socially distance and take other precautionary measures amid the COVID-19 pandemic.</p><p style="margin-left: 20px;">"Christian nationalism was the leading predictor that Americans engaged in incautious behavior during the pandemic, and the second leading predictor that Americans avoided taking precautionary measures."</p><p>But that's not to say that religious beliefs are causing Americans to reject mask-wearing or social distancing. In fact, when the study accounted for Christian nationalist beliefs, the results showed that Americans with high levels of religiosity were likely to take precautionary measures for COVID-19.</p>
Limitations<p>Still, the researchers note that they're theorizing about the connections between Christian nationalism and COVID-19 behaviors, not documenting them directly. What's more, they suggest that certain experiences — such as having a family member that contracts COVID-19 — might change a Christian nationalist's behaviors during the pandemic.</p><p style="margin-left: 20px;">"Limitations notwithstanding, the implications of this study are important for understanding Americans' curious inability to quickly implement informed and reasonable strategies to overcome the threat of COVID‐19, an inability that has likely cost thousands of lives," they write.</p>
Parental anxieties stem from the complex relationship between technology, child development, and the internet's trove of unseemly content.