Browse through most plant stores and you’ll come across the promise of purified air. Peace lilies, snake plants, and ivy have small tags (pale blue or white, or other colors that suggest purity) declaring, “This plant cleans the air.” Popular online retailer Patch reserves an entire section of its website for “air-purifying indoor plants.” Another vendor, Plantler, offers an Air So Pure package of spiders, palms and ferns.
Much of the support for these marketing efforts began in 1989, when NASA worked with Associated Landscape Contractors of America to assess the ability of houseplants to remove toxins from the air. The resulting clean air study suggested that yes, houseplants can absorb certain pollutants, including VOCs such as benzene, formaldehyde and trichlorethylene. The fact that these results have little applicability to the homes where these plants are often placed has been under-hyped. Putting the plants in an enclosed room, spraying them with pollutants for hours (or days) and then recording the results, the researchers admitted, did not exactly replicate normal houseplant conditions. bottom. This hasn’t stopped many researchers since they conducted almost identical experiments.
But in 2019, researchers at Drexel University found that to replicate the effects measured in these chamber experiments on a livable scale and match the toxin removal rates already achieved by simply opening windows , concluded that: You need 10 to 1,000 plants per square meter.
Richard Corsi, dean of engineering at the University of California, Davis, is also outraged by what he calls these “little glasshouse studies.” The problem, he says, is that in order to get results, researchers exaggerate the amount of air that flows over the plants under normal conditions. The industry standard metric for air filter effectiveness is the Clean Air Delivery Rate (CADR). Combining these measurements into one metric, he said, consumers are less likely to be fooled by air filters that, for example, remove toxins very efficiently, but are less likely to be fooled by air filters that are very efficient at removing toxins, but are less likely to Limited.
Using data from historical plant studies and CADR best-case scenario calculations, Corsi found that a 50% reduction in formaldehyde (and other VOCs) levels would require as many as 315 plants in an approximately 200-square-foot bedroom. said to be needed. A 90% reduction would require over 2,800 plants. Expanding it over an entire apartment or house fosters a dense jungle.
So, are Neoplants’ genetically engineered houseplants better? The company’s sales literature references a 1989 study, in which P1 claims “30% better than NASA’s top plants” when it comes to removing VOCs. It’s twice as good,” he claims. However, this was a lab-based study, where Neoplants pumped formaldehyde, benzene, toluene and xylene into a P1 sample contained within a 35-liter glass chamber and compared outputs.Field tests still yielded reliable results. However, it is hoped that new labs with specially designed non-adsorption chambers will allow more realistic testing in the future.
