Mold is a problem in many homes, with consequences for health, especially for people with allergies and respiratory problems. A NASA study identified 50 plants good for filtering the air, not only from mold spores, pet dander, but also various types of chemicals. Good allies for a better environment.

The rainy winter, extending from autumn, contributes to exacerbating the risks of mold appearing in homes, particularly in bedrooms and bathrooms. A problem for people with respiratory difficulties or allergies, affecting the health of everyone in a dwelling. But it's not just what's visible that is worrying. According to the North American Space Agency (NASA), indoor air is 30 times more toxic than outdoor air. Besides mold, the indoor environment may be polluted with chemicals such as ammonia, benzene, formaldehyde, trichloroethylene, among others.

Aware of this problem, and within a framework that had as its horizon space exploration and the search for plants capable of purifying the air and even producing small amounts of oxygen, NASA conducted a study, published in 1989, to understand which were the best plants to have in an enclosed space like a space station... or a house. The research found 50 plants capable of purifying the air, many of them present in millions of homes for many years, almost all accessible in price and easy to maintain - after all, they thrive in humid and poorly lit spaces!

The study, conducted by B.C. Wolverton, Chief of the Stennis Environmental Research Laboratory, analyzed dozens of common houseplants and tested their ability to remove a variety of toxins, such as formaldehyde, ammonia, or benzene, among others. The goal was to understand which plants filtered certain pollutants better. This resulted in a table that has been circulating worldwide for the past 34 years and which includes plants that can also be very useful in combating mold in homes.

"Unfortunately, there are not many studies on the amount of air that plants can purify," lamented Leonardo Marotta, Ph.D. in Environmental Sciences, admitting, however, that the subject is studied by engineers and architects when assessing the plants they place in buildings. "Plants have a great capacity to move air and manage humidity; the environment becomes cleaner," he adds.

Feed on pollutants and mold to grow

According to Wolverton's study, plants harness air pollutants to grow. "The roots and associated microorganisms destroy pathogens such as viruses, bacteria, and organic chemicals, converting these pollutants into plant tissue," explains an article from NASA about the work published in 1989.

An external professor of Environmental Systems and Biomimetics at the IUAV University of Venice, Leonardo Marotta recalls a project he did for a waste treatment company in Italy. The placement of plants known for their ability to absorb pollutants contributed to "the improvement of humidity levels and air quality" in that facility.

But, plants alone are not enough. High humidity levels and poor ventilation are fertile ground for mold progression. Plants can be good friends of the environment and health at home, but in homes with humidity problems, and others too, it is important to promote proper ventilation of spaces, both indoors, by opening doors for air to circulate through all rooms, and outdoors, by opening windows to renew the air.