What to Know About Alternaria Mold

Indoor mold growth is never a good thing, as it indicates moisture issues or unknown leaks within your home. However, some molds are more dangerous than others. It’s important to learn how to identify common household molds so you can distinguish between those that pose a mild risk and those that are a critical health hazard. This is especially crucial if you or your loved ones have compromised immune systems, allergies or asthma, as mold can trigger serious reactions in these individuals.

One group of molds that definitely shouldn’t be ignored is Alternaria. This mold type is typically found outdoors but can make its way into your home. It can then take root in damp environments like bathrooms, basements and under sinks. In this guide, we’ll cover the dangers of Alternaria, how to identify it and the best way to remove it from your home for good with tips from Michael Sacenti of American Healthy Homes.

What Is Alternaria Mold?

Alternaria is a collection of nearly 300 mold species found all over the world. The club-shaped spores develop into long, chain-like structures, eventually growing into thick black, green or gray colonies. Spores spread in the air, often settling in water or soil. Alternaria molds are some of the most common causes of decomposition, and are responsible for at least 20 percent of agricultural spoilage. These molds aren’t all bad, though. Some have performed well as bio-control agents that help keep invasive plant species in check.

Where Is It Commonly Found?

Alternaria is predominantly an outdoor family of molds, so any growth that happens in your home likely began with spores from outside. “It mostly grows on plants and is considered a plant-based fungus,” Sacenti says. “It’s fairly rare to see inside a home.” But if it does find its way inside, it can colonize on tiles, drywall, plywood and even paint and polyurethane. Like most molds, it grows best in dark, damp areas.

What Are the Health Effects?

Alternaria can cause many health problems, mainly a variety of allergies. A 2007 study of 75 U.S. locations showed a marked increase in asthma symptoms in homes with higher Alternaria concentrations. Spores can take root on eyeballs, mucus membranes and in the respiratory tract. Most Alternaria species don’t cause serious infections in healthy people, but “anyone with underlying health conditions is at the highest risk,” Sacenti says.

How to Remove and Prevent Alternaria Mold

The first step to removing Alternia mold is identifying and drying areas of excessive moisture in your home. This will make it harder for new mold to grow and existing mold to spread. Since Alternaria spores almost always come from outside, be sure to keep doors and windows closed during spring and summer if you think you may have a mold problem. Ample ventilation can be achieved with a heat recovery ventilator (HRV), which will help improve indoor air quality and decrease mold growth. If you can find visible mold, use a non-toxic fungicide to remove it. If you don’t see any mold but develop sudden asthmatic symptoms or other respiratory issues, consider hiring a professional mold removal team.

About the Expert

• Michael Sacenti owns American Healthy Homes. He has 10 years of experience in the mold remediation industry and 40 years of experience in real estate maintenance.