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How Plants Boost Air Quality in Closed Spaces

Indoor air quality is an important but often overlooked aspect of health and wellbeing. The air inside our homes and workplaces can be more polluted than outdoor air, containing harmful contaminants like mould, chemicals from cleaning products, particulate matter, and volatile organic compounds from furnishings and building materials.

Poor indoor air quality has been linked to headaches, fatigue, trouble concentrating, irritation of the eyes, nose, throat and lungs. With most people spending 90% of their time indoors, it’s clear that the quality of air inside is critically important.

Luckily, there is a natural and beautiful solution to purify indoor air – plants! Houseplants are nature’s air filters, removing pollutants and releasing fresh oxygen through the process of photosynthesis. As early as the 1980s, NASA studies found that certain houseplants could effectively remove volatile organic compounds like formaldehyde, benzene, and trichloroethylene from the air.

Adding plants to your home or office decor helps create a healthier indoor environment. Their ability to filter the air while adding warmth and beauty makes incorporating plants an easy way to boost air quality in any closed space.

How Plants Improve Air Quality

Plants can improve indoor air quality through two key processes – photosynthesis and phytoremediation. During photosynthesis, plants take in carbon dioxide and release oxygen. This helps counteract the carbon dioxide that humans exhale and provides us with fresh oxygen.

Phytoremediation is the process by which plants absorb and break down pollutants in the air. Plants can absorb many common volatile organic compounds (VOCs) like benzene and formaldehyde through their leaves and roots. These pollutants can come from materials like plastics, cosmetics, and carpets. The phytochemicals and water vapour released through transpiration also help circulate air and pull toxins into the plants.

The types of plants best suited for improving indoor air are those adapted to low light and limited air circulation, like many rainforest floor plants. When planning an indoor plantscape, it’s important to choose the right mix of species that will thrive in the environment. With the help of experts, offices and homes can become cleaner and healthier through the natural air filtration effects of plants.

NASA Research on Indoor Plants

Studies funded by NASA in the 1980s first demonstrated the air-purifying capabilities of indoor plants. NASA was interested in creating closed ecological systems with plants to support long-duration space missions. Their research showed that common houseplants like golden pothos, spider plants, and peace lilies could effectively remove volatile organic compounds from sealed test chambers.

In one experiment, NASA scientists placed houseplants in sealed plexiglass chambers containing high concentrations of VOCs. They found that the plants could reduce indoor air pollutants by up to 87 percent within 24 hours. Follow-up studies tested additional plant species and VOC types, further proving the phytoremediation potential of indoor plants.

Dry Deposition Process

Plants are able to absorb gaseous pollutants through their stomata, the tiny pores on leaf surfaces. This process is called dry deposition. As air moves across the plant’s surface, pollutant gases diffuse into the stomata and become trapped or adsorbed by water films on the plants. The pollutants can then be incorporated into the plant’s biological processes.

Certain plant traits like leaf hairiness, oiliness, and stickiness can enhance dry deposition. Plants with large, hairy leaves provide more surface area for trapping airborne particles. Some studies have found that spider plants and pothos excel at dry deposition due to their leaf structure.

Benefits of Improved Air Quality

Having plants in indoor spaces can provide a variety of benefits related to improved air quality. First and foremost, by absorbing toxins and producing oxygen through photosynthesis, plants can directly improve the air we breathe. Studies have shown that certain plants are particularly effective at removing harmful volatile organic compounds like formaldehyde and benzene from the air.

Beyond their air filtering abilities, plants can also boost humidity levels. Most indoor environments are quite dry, which can irritate respiratory systems and skin. By releasing moisture into the air through transpiration, plants add much-needed humidity to dry indoor air.

There are also less direct but equally important benefits of having plants in interior spaces. The presence of plants can make indoor environments seem more natural and inviting. Greenery and nature views have been shown to reduce stress, improve cognitive performance, and enhance moods. Plants essentially bring the outdoors inside, adding life and vibrancy to otherwise sterile indoor settings.

Furthermore, plants can act as natural sound absorbers and provide a sense of privacy in shared spaces. The simple act of caring for houseplants can also be therapeutic and fulfilling for many people. Overall, the benefits of improved air quality through plants extend far beyond just filtration effects.

Key Benefits of Plants in Indoor Spaces

  • Directly improve air quality through photosynthesis and pollutant removal
  • Increase humidity levels in dry indoor environments
  • Reduce stress and enhance moods by bringing nature indoors
  • Absorb noise and create privacy in shared spaces
  • Provide therapeutic value through caring for plants
How Plants Boost Air Quality in Closed Spaces
How Plants Boost Air Quality in Closed Spaces

Controversies and Criticisms

While many studies have demonstrated the ability of plants to improve indoor air quality through removing pollutants, some research has presented conflicting results. A few key controversies and criticisms surrounding the use of plants as natural air filters include:

Mixed Research Findings

Some studies have found that certain plants are more effective at removing specific pollutants like benzene or formaldehyde, while other studies show minimal effects. The NASA research from the 1980s that popularised the air-purifying ability of plants has received criticism regarding experimental methods and plant maintenance procedures.

Depends on Various Factors

The extent to which plants can improve air quality seems to depend on several factors like the number and placement of plants, ventilation and air circulation, type of pollutants, and more. Under certain conditions, plants may have negligible or short-lived effects on indoor pollutant levels.

Potential Release of Volatile Organic Compounds

While absorbing pollutants through leaves, some plants may release volatile organic compounds that can negatively impact air quality. The types and amounts released can vary considerably between plant species.

Limited Capacity and Slow Process

Plants have a limited capacity to remove pollutants and may take a long time to make a significant improvement in indoor air quality. The plant’s size, growth rate, and other factors constrain its filtering capacity.

Not a Replacement for Ventilation

Most experts agree that plants should complement, not replace, adequate ventilation systems. Relying solely on plants to filter indoor air is unrealistic in most settings.

While plants have demonstrated an ability to remove some pollutants under certain conditions, more research is needed to fully understand their limitations and potential. Caution should be taken against overstating the air-purifying benefits of plants indoors.


To recap, this blog post has explored the ability of plants to boost air quality in enclosed spaces. Through the process of photosynthesis, plants take in carbon dioxide and release oxygen, helping to purify indoor air. While the degree of plants’ air-purifying impact remains debated, the overall evidence suggests they provide benefits. Incorporating more plants can enhance indoor air quality and human well-being.

Key Takeaways

  • Plants naturally filter air through photosynthesis and other processes.
  • Research shows plants reduce indoor pollutant levels, though the extent varies.
  • Better air quality positively impacts health, comfort, and productivity.
  • More research is still needed to optimise air-purifying plant systems.

Given these takeaways, readers are encouraged to add more plants to their home or office. Even a few strategically placed plants can make a difference. Consider species like peace lilies, English ivy, and snake plants that excel at filtering indoor air.

Expert Assistance

For tailored guidance on incorporating plants for better air quality, consult the specialists at Aztec Plants. Their expertise can help determine the ideal plants and placements to purify and refresh your unique environment. Plants offer a simple way to enhance our indoor air that is aesthetically pleasing and brings natural elements indoors. While not a cure-all, they provide measurable benefits that contribute to healthier, more enjoyable indoor spaces.  Contact Aztec Plants today to boost your indoor spaces with natural air-cleaning solutions.

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