{"id":7886,"date":"2022-04-22T09:00:26","date_gmt":"2022-04-22T07:00:26","guid":{"rendered":"https:\/\/www.breeze-technologies.de\/?p=7886"},"modified":"2022-04-25T16:21:18","modified_gmt":"2022-04-25T14:21:18","slug":"do-plants-improve-air-quality","status":"publish","type":"post","link":"https:\/\/www.breeze-technologies.de\/de\/blog\/do-plants-improve-air-quality\/","title":{"rendered":"Do plants improve air quality?"},"content":{"rendered":"

According to an often-quoted study conducted by NASA, house plants have been found to purify the air and remove \u201cup to 87% of the amount of toxins in the air\u201d. Recent studies, however, have cast doubt on these statements finding that indoor plants actually have no significant effect on improving indoor air quality (IAQ). What is the real scientific evidence behind these claims, and why do the findings of these studies differ so much? Read on more to find out.<\/span><\/em><\/p>\n

The link between plants and indoor air quality<\/b><\/h2>\n

Why are we interested in the potential of plants to improve indoor air quality? Generally speaking, plants are known for their ability to turn carbon dioxide into oxygen in a process called photosynthesis<\/a>, thereby creating the foundation of life on earth. Photosynthesis includes capturing carbon dioxide (CO2<\/sub>)<\/a> from the air, alongside water (H2<\/sub>O) from the air and ground, and light energy from the sun to create glucose (sugars) and oxygen (O2<\/sub>). However less well-known is that plants also release CO2<\/sub> back into the atmosphere<\/a> through respiration. Cellular respiration<\/a> is the process by which plants combine O2<\/sub> with food molecules, keeping necessary substances and discarding CO2<\/sub> and water as waste products. Photosynthesis happens in the presence of sunlight; in its absence plants use cellular respiration to survive.<\/span><\/p>\n

Existing research<\/span><\/a> has identified certain benefits of plants in interior spaces:<\/span><\/p>\n

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  1. Indoor air quality<\/b>. <\/span>Studies funded by NASA<\/span><\/a> showed that plants reduced levels of some indoor pollutants and can raise relative humidity to healthier and more comfortable levels indoors.<\/span><\/li>\n
  2. Well-being<\/b>. <\/span>Numerous studies<\/span><\/a> showcase plants to reveal a number of positive feelings associated with plants. <\/span>Studies<\/span><\/a> have also shown that plants can also have productivity effects and reduce mental fatigue.<\/span><\/li>\n
  3. Health Improvement<\/b>. Plants can have a decorative value through which they can even influence pain tolerance. Rooms with plants were found to be significantly more interesting, comfortable, and ornate than rooms without them. Plants can thereby serve as a distraction to help keep one\u2019s mind off of discomfort.\u00a0<\/span><\/li>\n
  4. <\/li>\n<\/ol>\n

    Can plants really improve air quality?\u00a0<\/b><\/h2>\n

    There are some mixed assumptions that prove for and against why plants really improved air quality. Critical reviews, studies, and research can be accounted for both sides:<\/span><\/p>\n

    Zoric and colleagues<\/span><\/a> proposed in their research to promote the role of plants in human lives, as well as to develop a system of assessment and potential improvement of air quality. They conducted their studies by placing eight plants (called Sansevieria trifasciata \u2018Laurentii\u2019) into a bedroom environment. Zoric et al. argue that based on their findings, the potted plants did not have a significant, positive impact on <\/span>CO2<\/sub><\/span>, methane, and <\/span>volatile organic compound (VOCs)<\/span><\/a> concentrations in the indoor air.<\/span><\/p>\n

    Cummings and Waring<\/span><\/a> wanted to look further and analyze whether plants have an effect in reducing indoor VOC counts and improving air quality. They investigated this by standardizing 196 experiment results into a metric useful for measuring the identified indoor air cleaning capacity. Upon analysis, they discovered that many of the analyzed studies did not assess the same VOC combinations. Still, they identified some positive air quality impact(s) from plants: they observed lower levels of formaldehyde or benzene in the rooms\u2019 air. Even though these positive effects were identified, the levels of formaldehyde and benzene did not occur simultaneously, meaning that plants improved one aspect at a time. Moreover, they were able to see that the measured clean air delivery rate (CADR) varied so much between individual studies that it might actually be more likely to be based on the different removal measurement methodologies used in those studies.<\/span><\/p>\n

    Gubb and colleagues<\/span><\/a> investigated how potted plants might actually have an effect in removing <\/span>nitrogen dioxide (NO2<\/sub>)<\/span><\/a>. They conducted an NO2<\/sub> chamber experiment on three common houseplant in different conditions: exposing the plants to light vs. having no light present, potting the plants in wet vs. dry substrate (the substance needed for plants to grow roots and absorb nutrients).The researchers found the following:<\/span><\/p>\n