Many websites claim that certain household plants remove indoor air pollution. Such plants are Aloe Vera, Spider Plant, Snake Plant, Warneck Dracaena, Pothos Ivy, and Bamboo Palm.
The scientific research shows that these plants remove between 2 to 5 percent of the pollutants in the air. That is too little to matter.
The reason is that many trials are done in small chambers with very high pollutant concentrations. In such situations, the plants show a reduction in pollutants.
In real life, though, spaces are much bigger and pollutant concentrations are much lower. Under such conditions, the plants struggle to clear out pollutants. In nutshell, don’t expect any benefit of using plants to lower indoor pollution.
- One needs to be careful when evaluating research about indoor plants. Many clinical trials use a high pollutant concentration in a small closed chamber for testing. When kept in high ambient levels of pollutants, many plants absorb them.
However, in normal life, such high levels of pollutants are not encountered. A reduction from 20% pollutant concentration to 18% is different from 0.2% concentration reducing to 0.18%. Though both are identical percentages of reduction, the underlying mechanisms may be different because such absorption is often non-linear.
- The trials may be observing the Hormesis Effect. Hormesis is defined as a dose-response phenomenon characterized by low-dose stimulation and high-dose inhibition. In such situations, mild environmental stress and severe environmental stress act in opposite ways. A little bit of exercise may be good for the body, while extreme sports may be damaging. A little amount of alcohol may be beneficial to the body, while excessive drinking may be harmful. Similarly, a plant may not respond to mild pollution while it will respond aggressively to high levels of pollutants by removing them.
- If the household plants need watering, one risks growth of fungus and fungal spores, which can cause respiratory issues. In general, it is not a good idea to risk this.
- Finally, why would someone try to rely on plant-based filtration when an inert HEPA-filter-based air purifier can give a confirmed benefit without any negative side effect?
For More Reading
- National Geographic: Which houseplants should you buy to purify the air? None of them
- The Atlantic: A Popular Benefit of Houseplants Is a Myth
- On this website: Indoor Air Pollution: An Overview
- On this website: Air Pollution: Various Acronyms, Numbers, and Units
First Published on: 21st November 2021
Image Credit: Huy Phan from Pexels
Last Edited on: 11th December 2021