NASA Plant Study: Fact vs. Fiction

Introduction: Breathing Easier with Houseplants? Unpacking the NASA Clean Air Study

Houseplants are having a moment. They brighten our living spaces, add a touch of nature indoors, and—we've long been told—purify the air we breathe. Much of this belief stems from a landmark piece of research: the NASA Clean Air Study. Published in 1989, this study investigated the ability of common houseplants to remove volatile organic compounds (VOCs) from sealed chambers. But how well do these findings translate to real-world conditions in our homes and offices? This article will delve into the details of the NASA Clean Air Study, separating fact from fiction and providing practical advice on using houseplants to improve your indoor air quality.

What the NASA Clean Air Study Actually Found

The NASA Clean Air Study, conducted in collaboration with the Associated Landscape Contractors of America (ALCA), aimed to find a natural way to purify the air in space stations. Researchers tested a variety of common houseplants for their ability to remove specific VOCs from sealed, controlled environments. These VOCs included:

• Formaldehyde: Found in many household products, including furniture, upholstery, and cleaning agents.
• Benzene: A component of gasoline, cigarette smoke, and some plastics.
• Trichloroethylene: Used in some cleaning fluids and adhesives.
• Xylene: Found in paints, varnishes, and adhesives.
• Ammonia: Present in cleaning products, fertilizers, and some fabrics.

The study found that several plants demonstrated significant effectiveness in removing these pollutants. Some of the top performers included:

• Peace Lily (Spathiphyllum): Effective against formaldehyde, benzene, trichloroethylene, xylene, and ammonia.
• Snake Plant (Sansevieria trifasciata): Particularly good at removing formaldehyde and benzene. Also converts carbon dioxide to oxygen at night.
• Spider Plant (Chlorophytum comosum): Efficient at removing formaldehyde and xylene.
• English Ivy (Hedera helix): Effective against benzene, formaldehyde, trichloroethylene, xylene, and toluene.
• Golden Pothos (Epipremnum aureum): Good for removing formaldehyde, xylene, and toluene. Note: This plant is toxic to pets.
• Chinese Evergreen (Aglaonema modestum): Effective against formaldehyde and benzene.
• Bamboo Palm (Chamaedorea seifrizii): Filters formaldehyde, benzene, and trichloroethylene.

The results were promising, suggesting that houseplants could play a role in improving indoor air quality. However, it's crucial to understand the limitations of the study before filling your home with greenery.

The Great Indoors: Applying NASA's Findings to Your Home

While the NASA study provided valuable insights, applying its findings to real-world indoor environments requires careful consideration. Here's where the "fact vs. fiction" comes into play:

The Scale Problem: It Takes a Forest

The NASA study was conducted in small, sealed chambers. Translating those results to a typical home or office environment is problematic. Research suggests that to achieve a comparable level of air purification, you would need a substantial number of plants – far more than most people typically keep in their homes. A study by researchers at Drexel University found that the number of plants required to significantly impact air quality in a typical room is so high that it's impractical. ( Drexel University News )

Ventilation Matters More

Modern homes are often well-ventilated, which means that outside air is constantly exchanging with indoor air. This ventilation dilutes the concentration of VOCs far more effectively than plants alone. Opening a window or using an air purifier with a HEPA filter can have a much more significant impact on air quality than a few houseplants. A review article published in *Environmental Science & Technology* also highlights that ventilation rates play a significant role in determining the effectiveness of plants in removing VOCs ( Environmental Science & Technology ).

Soil Microbes: The Unsung Heroes

While the plants themselves contribute to VOC removal, a significant portion of the purification process is attributed to microorganisms in the soil. These microbes break down VOCs, effectively cleaning the air. However, the effectiveness of soil microbes depends on various factors, including the type of potting mix, moisture levels, and the presence of other contaminants.

Beyond Air Purification: The Real Benefits of Houseplants

Even if houseplants aren't the miracle air purifiers we once thought, they still offer numerous benefits for our well-being:

• Improved Mood and Reduced Stress: Studies have shown that being around plants can lower stress levels, improve mood, and increase feelings of well-being. Research in the *Journal of Physiological Anthropology* found that interaction with indoor plants can reduce psychological and physiological stress. ( Journal of Physiological Anthropology )
• Increased Productivity: Plants in the workplace have been linked to increased productivity and creativity.
• Enhanced Aesthetics: Houseplants add visual appeal and create a more inviting and comfortable living space.
• Humidity Regulation: Plants release moisture into the air through transpiration, which can help to increase humidity levels, especially during dry winter months.

Practical Tips for Incorporating Plants into Your Home

Ready to bring some greenery into your life? Here are some practical tips:

1. Choose the Right Plants: Select plants that are well-suited to your home's environment (light levels, temperature, humidity). Research the specific needs of each plant before bringing it home.
2. Proper Placement: Position plants in locations where they will receive adequate light and air circulation. Consider the plant's mature size and growth habit when choosing a location.
3. Water Wisely: Overwatering is a common cause of plant death. Allow the soil to dry out slightly between waterings, and ensure that your pots have drainage holes.
4. Use Quality Potting Mix: Choose a potting mix that is appropriate for the type of plant you are growing. A well-draining mix is essential for most houseplants.
5. Fertilize Regularly: Feed your plants with a balanced fertilizer during the growing season (spring and summer).
6. Clean the Leaves: Dust and grime can accumulate on plant leaves, hindering their ability to photosynthesize. Wipe the leaves regularly with a damp cloth.
7. Consider Companion Planting: Some plants thrive when grown together. Research companion planting to create a harmonious and productive indoor garden.

Actionable Advice: Creating a Healthier Indoor Environment

To truly improve your indoor air quality, consider a multi-pronged approach:

• Increase Ventilation: Open windows regularly to allow fresh air to circulate. Use exhaust fans in bathrooms and kitchens to remove moisture and odors.
• Invest in an Air Purifier: A high-quality air purifier with a HEPA filter can effectively remove dust, pollen, pet dander, and VOCs from the air.
• Reduce Sources of VOCs: Choose low-VOC paints, furniture, and cleaning products. Avoid smoking indoors.
• Maintain Proper Humidity: Use a humidifier during dry winter months to maintain a comfortable humidity level.
• Incorporate Houseplants: While not a complete solution, houseplants can contribute to a healthier and more pleasant indoor environment. Choose a variety of plants known for their air-purifying qualities, and place them strategically throughout your home.

Conclusion: Appreciating Plants for What They Are

The NASA Clean Air Study sparked a popular belief in the air-purifying power of houseplants. While the study's findings are valid, it's crucial to interpret them within the context of real-world conditions. Houseplants, on their own, are unlikely to drastically improve indoor air quality. However, they offer a range of other benefits, including improved mood, reduced stress, and enhanced aesthetics. By understanding the limitations of houseplants as air purifiers and combining them with other strategies, such as increased ventilation and the use of air purifiers, you can create a healthier and more enjoyable indoor environment.

Next Steps:

Ready to take the next step in improving your indoor environment? Here’s what you can do:

1. Assess Your Home: Identify potential sources of VOCs and areas where ventilation could be improved.
2. Choose the Right Plants: Research plants that suit your environment and needs. Focus on variety for maximum benefit.
3. Invest in Air Purification: Consider purchasing a high-quality air purifier to complement your plants.
4. Stay Informed: Keep up-to-date with the latest research on indoor air quality and adjust your strategies accordingly.
5. Enjoy the Process: Embrace the joy of gardening and the beauty that plants bring into your life.