How Indoor Plants Reduce VOC: Research and Practical Points

Indoor plants not only bring a touch of green to our living spaces and offer visual pleasure, but they also possess an unknown "special ability" – quietly improving the quality of the air we breathe. Especially when facing the troubling volatile organic compounds (VOCs), plants demonstrate their unique purification capabilities. VOCs are ubiquitous, potentially emitted from paints, cleaning products, new furniture, and carpets. Long-term exposure to high concentrations of VOCs can lead to discomforts such as headaches, nausea, and allergies in mild cases, and even affect physical health in severe cases. Therefore, it is necessary for us to take this invisible threat seriously.

How Do Plants "Consume" VOCs ingeniously?

The process by which plants purify VOCs is by no means a single mechanism; rather, it's a sophisticated "combo" where multiple mechanisms work synergistically, which is quite astonishing:

1. Leaves: The "Primary Catchers" of VOCs

Plant leaves, especially those covered with stomata, are the main force in absorbing airborne VOCs. You can imagine that when VOC molecules drift to the leaf surface, some will "sneak" into the plant's interior through these tiny pores. Although stomata primarily serve the plant's respiratory function, they also "absorb" various gas molecules, which can be inhaled in small amounts.

2. Root Microbes: The True "Unsung Heroes"

In my opinion, this is the most miraculous and crucial aspect of plant VOC purification. Around the plant's root system lives a group of diligent microorganisms, acting as the plant's "helpers." These microbes can treat organic pollutants in the soil, including VOCs absorbed by plants from the air and transported to the roots, as delicious "food" for decomposition. They secrete specific enzymes to break down complex organic molecules into simpler, harmless carbon dioxide and water, which is truly amazing.

3. The Plant's Internal "Purification Factory"

Once VOCs are absorbed by the plant, they do not remain "idle" within the plant. Plants possess their own "digestive system," consisting of various enzymes capable of converting these VOCs into non-toxic or less toxic compounds. They are then stored or integrated into the plant's cellular structures, for example, converted into cellulose or lignin. This is like the plant silently "detoxing" itself while also purifying our environment.

Insights from Scientific Research

When discussing plant air purification, one must mention the famous NASA study from the 1980s. At that time, to find effective air purification solutions in enclosed space stations, NASA conducted numerous experiments. The results were surprising: common indoor plants such as spider plants, pothos, snake plants, English ivy, and areca palms showed significant removal capabilities for common VOCs like formaldehyde, benzene, and trichloroethylene. This discovery caused a sensation at the time and laid a solid foundation for subsequent research.

Over the next few decades, scientists worldwide did not stop there; they delved deeper into NASA's findings and drew some interesting conclusions:

"Specialization in the Field": I found that different plants indeed exhibit differentiated purification effects on various types of VOCs. For example, English ivy is particularly effective at removing benzene and formaldehyde, while gerbera daisies excel at degrading benzene. This indicates that each plant has its unique "specialty."
Multiple Influencing Factors: The type and number of plants, the activity of potting soil microbes, indoor light, temperature, humidity, and even air circulation, all affect the efficiency of plant VOC purification. Generally, plants with larger leaves and vigorous growth will have better purification effects, which is understandable, as they have a larger "working" area.
Persistence is Key, Gradual and Steady: I believe that although the "immediate" purification ability of plants may not be as instant as professional air purifiers, they offer a continuous, low-cost air purification solution. Furthermore, plants are crucial for maintaining the activity of potting soil microbes, which is a key link in VOC degradation.

My Practical Tips

Combining these research findings, I have summarized some small tips for using indoor plants to reduce VOCs in daily life, hoping to provide some reference:

1. Select "Star Plants":

Choosing plants that have been proven to have good removal capabilities for multiple VOCs will result in more significant purification effects.

Spider Plant: Helps with formaldehyde, xylene, and carbon monoxide.
Snake Plant: An expert in absorbing formaldehyde and benzene.
Pothos: Also effective against formaldehyde, benzene, and trichloroethylene.
English Ivy: Especially good at absorbing benzene and formaldehyde, a "purification vanguard."
Areca Palm: Formaldehyde, benzene, trichloroethylene, an "all-rounder."
Aloe Vera: Also has some ability to absorb formaldehyde.
Gerbera Daisy: Shows excellent effects on benzene and trichloroethylene.

2. "Sufficient" Quantity is Needed:

Although there isn't a universal "magic number," if you want to achieve a noticeable purification effect, I recommend placing 2-3 medium-sized plants in each room. If the room area is 10-20 square meters, placing 3-5 plants might have a better effect, as "many hands make light work."

3. Ensure Healthy Plant Growth:

This is crucial! Healthy plants work efficiently. Remember to water regularly, fertilize, provide ample light and appropriate temperature, and promptly remove dead leaves. Healthy roots and active soil microbial communities are the "secret weapons" for degrading VOCs.

4. Care for Potting Soil Microbes:

As I emphasized earlier, microorganisms in the potting soil are the unsung heroes of VOC degradation. Therefore, avoid overwatering which can lead to root rot, and also avoid abusing fungicides, so as not to destroy the microbial living environment. Proper ventilation can also make these "little guys" more active.

5. Plants Are Only "Auxiliary Roles":

I want to emphasize that indoor plants are good helpers for air purification, but not the only solution. Especially in newly renovated homes, ventilation remains the top priority, and efforts should be made to use low-VOC building materials and furniture. Air purifiers can quickly reduce VOC concentrations in a short time, while plants provide a continuous, more ecological purification method. Combining the two will yield even better results.

In conclusion, indoor plants are undoubtedly ideal companions for home life. They actively contribute to reducing indoor VOCs through ingenious mechanisms such as leaf absorption, root microbial degradation, and their own metabolism. Although their purification efficiency is affected by various factors, as a natural, beautiful, and continuously purifying method, judicious use of indoor plants will surely make our living environment healthier and more comfortable.