It’s gross, grimy and may be growing somewhere in your bathroom.
Black mold is the stuff of homeowners’ nightmares. It’s notoriously difficult to remove, can cause expensive property damage and has been blamed for a wide range of health problems.
But how worried should you really be about this pesky houseguest? Here’s what you need to know.
What is black mold?
There are many different kinds, but when people talk about black mold, they’re usually referring to Stachybotrys chartarum.
This greenish-black fungus occurs naturally in the environment and reproduces through microscopic spores that travel through the air. They can enter your home through open doors and windows, ventilation systems or by hitching a ride on pets, clothing and shoes.
Once inside, the mold can take hold if conditions are right. It thrives in warm, persistently damp environments with access to cellulose — an organic material found in drywall, paper and wood.
That’s why it commonly crops up in water-damaged areas of the home, including basements, bathrooms, laundry rooms and around leaky windows.
Is black mold dangerous?
It can cause health problems, but it’s not necessarily more dangerous than other household molds, according to the Cleveland Clinic.
Like other fungi, black mold can trigger allergies and respiratory problems. Some species, including Stachybotrys chartarum, can also produce mycotoxins — naturally occurring toxins that can be harmful at high doses.
But just because mold can produce toxins doesn’t mean it’ll poison you. Scientists haven’t established that typical household exposure delivers enough mycotoxins to cause the chronic, whole-body poisoning often blamed on “toxic black mold syndrome.”
What physical symptoms can black mold cause?
For some people, mold exposure causes no noticeable problems. Others may develop itchy, red eyes, nasal congestion, sore throat, coughing, wheezing and skin rashes, according to the Centers for Disease Control and Prevention.
People with asthma, mold allergies or weakened immune systems are more vulnerable to complications, including fungal infections in some cases.
Those exposed to large amounts of mold, such as farmers handling moldy hay, may also experience more severe reactions.
Can black mold cause psychological symptoms?
This is where things get murkier.
People living or working in damp, moldy buildings have reported fatigue, headaches, anxiety, depression and cognitive problems, including brain fog and trouble concentrating.
Some animal studies have found that mice exposed to high doses of Stachybotrys spores developed brain inflammation, memory problems and anxiety-like behaviors.
However, major medical organizations point out that no controlled human studies have proven that normal indoor mold levels deliver enough mycotoxins to cross the blood-brain barrier and cause neurological damage.
That said, there are other possible explanations for the psychological symptoms people exposed to mold report.
For example, constant allergies, sinus congestion and asthma flare-ups can disrupt sleep, leaving people exhausted, irritable and mentally foggy.
Dealing with a mold-infested home, worrying about its potential health effects and trying to get to the bottom of unexplained symptoms can also take a psychological toll, potentially worsening existing mental health conditions or contributing to new ones.
“This chronic stressor can lead to heightened anxiety and depressive symptoms, which, in turn, may foster psychosis in susceptible individuals,” according to the Neuroscience Institute.
Damp buildings may also have other irritants, including bacteria and dust mites, that contribute to headaches and other symptoms.
What should you do if you find black mold in your home?
First, tackle the moisture problem. Repair leaky pipes and windows, address water damage and improve ventilation to keep mold from returning.
For smaller patches on hard surfaces, the CDC recommends scrubbing with hot, soapy water or an appropriate commercial mold cleaner. Wear gloves, goggles and an N95 respirator while cleaning.
Moldy porous materials, including carpeting, insulation and drywall, may need to be removed and discarded.
If the mold covers a large area, is growing inside walls or ventilation systems, or you’re experiencing allergic reactions while cleaning, call a professional mold remediation company to help remove it.
How do you treat symptoms caused by mold exposure?
In many cases, symptoms improve once the mold is removed and exposure stops.
For people with mold allergies, antihistamines, nasal sprays, decongestants and eye drops can relieve symptoms, according to the Mayo Clinic.
Allergy shots, also known as immunotherapy, may also help some people build up tolerance to specific mold allergens over time.
But before you open your wallet to purchase one of the pricey mold detoxes being hawked online, you might want to think twice.
Medical and toxicology experts say there’s no good evidence that you need a special cleanse to rid your body of mycotoxins from everyday household mold exposure.
