Concerns about indoor air quality, particularly the presence of mold and fungal spores, drive many people to seek natural solutions. A specific claim suggests that a single houseplant can remove an impressive 78% of airborne mold. This figure has captured public attention as a simple remedy. This article examines the plant behind this statistic, analyzes the scientific context of the mold removal claim, and explains how plants contribute to cleaner indoor air.
Identifying the Plant Associated with the Claim
The houseplant most frequently cited in connection with the 78% mold reduction figure is the English Ivy (Hedera helix). This vining plant gained its reputation after a study demonstrated its ability to filter a high percentage of mold particles quickly. Since English Ivy thrives in humid conditions, it is often recommended for placement in areas like bathrooms and kitchens where moisture levels are consistently higher.
While other plants like the Snake Plant (Sansevieria trifasciata) and the Peace Lily (Spathiphyllum) are recognized for air-cleaning properties, the precise 78% reduction claim is consistently linked only to the English Ivy. This specific figure propelled the plant into the spotlight as a potential solution for airborne mold issues.
Understanding the Context of the Mold Removal Study
The 78% reduction figure attributed to the English Ivy is rooted in research conducted under highly controlled laboratory conditions. The original studies, including those following the NASA Clean Air Study, were performed in small, sealed environmental chambers. These chambers were designed to be airtight, allowing researchers to introduce a known quantity of contaminants without the natural air exchange found in a typical home.
In this sealed environment, the plant’s ability to absorb or settle particles becomes the primary removal mechanism, leading to the rapid reduction observed. A standard residential home, however, experiences a constant rate of air exchange (ACH). This ventilation drastically dilutes pollutant concentrations and requires plants to work much harder to achieve a noticeable effect.
Applying the 78% figure to a large, ventilated living space is misleading because the concentration of mold spores is continually refreshed. The sheer volume of air means a single plant cannot realistically scrub the air to that degree. While English Ivy can trap mold spores, these controlled results do not translate directly into real-world mold remediation. The plant is a supplemental air quality improver, not a standalone solution for a serious mold infestation.
General Mechanisms of Air Purification by Plants
Houseplants contribute to cleaner air through several distinct biological processes. One key mechanism is phytoremediation, which involves the absorption of volatile organic compounds (VOCs), such as formaldehyde and benzene, through the leaves. These VOCs are then translocated to the root zone.
In the root system, symbiotic microorganisms break down the harmful VOCs into harmless byproducts, effectively removing chemical contaminants. Another mechanism is transpiration, where the plant releases water vapor through its leaves. This process draws air down toward the soil and roots, helping to pull airborne particles and toxins into the root zone for microbial breakdown.
Mold spores are biological particles, not gaseous VOCs, and are typically heavier than the toxins plants metabolize. Their removal is primarily achieved by physically settling on the sticky surfaces of the leaves or being trapped in the moisture boundary layer around the plant. Therefore, while plants actively metabolize VOCs, their effect on mold spores is more passive, acting mainly as a surface trap.
Other Recommended Plants for Indoor Air Quality
While no houseplant can replace professional mold remediation, several other species are recognized for filtering common indoor air toxins. The Peace Lily (Spathiphyllum) filters formaldehyde, trichloroethylene, and benzene, making it a comprehensive air quality aid. The Boston Fern (Nephrolepis exaltata) is particularly effective at removing formaldehyde, a common VOC found in many household materials.
The Spider Plant (Chlorophytum comosum) is a hardy choice that efficiently filters formaldehyde and xylene. These plants focus on removing VOCs that off-gas from furniture, cleaning products, and building materials, thereby improving the overall chemical quality of the air. Air-purifying plants are best utilized as a supplement to proper ventilation and should never be relied upon as the sole solution for significant moisture or mold problems.