What to Know About Alternaria Mold

Got mold in your home? It might be Alternaria, which can cause serious respiratory issues. Learn about Alternaria mold and how to eliminate it.

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Indoor mold growth is never a good thing, but some molds are more dangerous than others. Learning to identify common household molds and the health problems they cause can help shed light on symptoms you or a loved one may experience. One group of molds that definitely shouldn’t be ignored is Alternaria. Learn about this group of molds, the problems they cause and how to eliminate them.

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. Alternaria prefers plants and wood for growth. But if it finds 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 those with compromised immune systems are at serious risk if exposed.

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.

Steve Maxwell
Steve Maxwell is an award-winning content creator who has published more than 5,000 articles, shot countless photos and produced video since 1988. Using his experience as a carpenter, builder, stone mason and cabinetmaker, he has created content for Mother Earth News, Reader's Digest, Family Handyman, Cottage Life, Canadian Contractor, Canadian Home Workshop, and many more. Steve lives on Manitoulin Island, Canada with his wife and children in a stone house he built himself. His website gets 180,000+ views each month, his YouTube channel has 58,000+ subscribers and his weekly newsletter is received by 31,000 subscribers each Saturday morning.