Can Plants Improve Indoor Air Quality?

Air Quality Canada
August 8, 2022
6 Minutes

Can Plants Improve Indoor Air Quality?

If you’re interested in maintaining a healthy living environment, you may be wondering whether houseplants can improve the air quality in your home. After all, virtually everyone knows that plants extract carbon dioxide (CO2) from the atmosphere and could represent a partial solution to the ongoing climate crisis. Does it follow that investing in some beautiful plant life could clear some of the less desirable gases from your humble abode and reduce your carbon footprint? The answer is a little complicated. Here are the key takeaways about the link between plants and air improvement:

1. Plants can help to reduce CO2 levels in your home (but not by much…)

According to a study exploring the effects of human activity on air quality, you would need over 800 houseplants to offset every single liter of gasoline used in a vehicle. In the long term, therefore, filling your house with plants is unlikely to have a significant impact on air quality. Having said that, incremental improvements are better than nothing. While you may not be able to erase your carbon footprint with indoor horticulture alone, you’ve nothing to lose by placing a new spider plant or succulent on your favorite mantelpiece.

2. Plants can produce (harmless) mold

Most people do everything in their power to keep mold out of their homes. Usually, this involves maintaining good ventilation, preventing the development of damp, and using a dehumidifier if necessary. Unfortunately, however, many houseplants require humid environments to thrive and can develop mold on their leaves and the surrounding topsoil.

Before you start worrying, it’s worth pointing out that plant-related mold is often very different to the potentially more dangerous mold found in water-damaged homes. Plants typically produce a powdery substance that is harmless when breathed in by humans and does not represent a cause for concern. However, this mold does indicate that your plant may not be thriving. If there is mold present on the leaves or stem, your plant will start to wilt relatively quickly. Combat this by simply wiping the mold from the plant and, in advanced cases, killing the mold using hydrogen peroxide.

3. Plants have been said to lower levels of toxic compounds (but the evidence is contested)

In the late 1980s, NASA published a Clean Air Study stating that certain houseplants (including peace lilies, fig-trees, and more) could remove dangerous volatile organic compounds (VOCs) from the air. To reach this conclusion, scientists placed 12 different plant types in sealed rooms and tested whether they could reduce levels of benzene, formaldehyde, and trichloroethylene. After 24 hours, all plants had lowered the level of VOCs in the atmosphere by between 10% and 70%. Such striking reductions have led people to claim that plants can mitigate the health impacts of VOCs, including:

  • Dizziness
  • Nausea
  • Shortness of breath
  • Skin, eye, and throat irritation
  • Lung problems
  • Fatigue
  • Headaches

In fact, the NASA study has been cited for years as concrete evidence that indoor plants are beneficial to human health. VOCs are relatively common in many household products such as printers, paint, disinfectants, and air fresheners, so it makes sense to explore ways to mitigate their impact.

However, a recent review of 12 scientific studies questions the foundations of NASA’s influential report. After reading the wide array of available evidence, the authors of the review concluded that houseplants do not make any noticeable difference to human health or VOC concentrations. While the results of the original NASA experiments are certainly compelling, they involved controlled test environments that do not reflect the realities of the modern home.

So, should you purchase houseplants to reduce your risk from VOCs? According to the latest evidence, you would need thousands of plants to make any noticeable difference to your indoor air quality. The best ways to protect yourself from health issues include:

  • Switching to natural cleaning products
  • Increasing indoor ventilation by opening windows and doors more frequently
  • Following products labels carefully
  • Investing in an air purifier

4. Plants could boost the microbiome of your home

Although houseplants are unlikely to make a huge difference to the air quality within your home, they could positively impact the microbiome of your indoor spaces. A recent scientific study has demonstrated that houseplants could boost microbial diversity within the home and prevent harmful bacteria from developing. In the long term, this could produce a range of positive health outcomes, including:

  • Reduced risk of developing asthma
  • Reduced risk of developing allergies
  • Reduced risk of developing autoimmune diseases
  • Improved immune function

5. Houseplants come with tons of other benefits worth investigating

Finally, it is well worth considering the range of health benefits associated with houseplants. Although many scientists are skeptical about the effect of plants on air quality, there is much greater consensus on how plants can influence health in other ways. These include:

  • Reducing stress levels: Researchers have shown that filling your home and office with houseplants could have soothing and stress-busting effects.
  • Improving productivity: A study from several years ago shows that people who work around plants are more productive than those who do not. They also have fewer sick days.
  • Enhancing job satisfaction: A recent study of Amazon employees shows that spending time around plants improves your overall outlook on work and life.

Start growing your indoor garden today!

If you’re keen to transform your overall sense of wellbeing and make incremental improvements to the air quality in your home, why not start building your indoor garden? If you own pets or have children, we recommend avoiding the following potential toxic species:

  • Aloe vera
  • Cyclamen
  • English ivy
  • Jade
  • Philodendron
  • Sago palm
  • Umbrella plant

This list is not comprehensive, however, so remember to conduct some research beforehand. If enhancing air quality is your main goal, check out the following species:

  • Fig-tree
  • Areca palms
  • Bamboo palms
  • Boston fern
  • Spider plant rubber tree

As well as looking amazing, these plants are known for their absorptive powers.

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