How dangerous is black mold to health?
Some people may be more sensitive to mold spores than others, and they may develop respiratory symptoms after inhaling even a small number of spores. In large quantities, mold spores can cause ill health in almost anyone.
There is no single type of mold called “black mold” — many molds are black. When people use the term, they may be referring to a type called Stachybotrys chartarum (S. chartarum), also known as Stachybotrys atra.
Therefore, people should remove any mold growth in the home and take steps to prevent it from growing back.
There is a commonly held belief that black mold — sometimes called toxic mold — can cause severe health problems because it releases mycotoxins. Mycotoxins are toxic substances that a fungus produces.
Some research suggests that mycotoxins from S. chartarum have a link to serious health problems in people who live in contaminated buildings.
One such health concern is mycotoxicosis — mold poisoning. Others include:
- aches and pains
- changes in mood
- headaches
- memory loss
- nosebleeds
To date, there is no proof that inhaling mold spores causes these symptoms.
Mold exposure can cause other symptoms, however. According to the Florida Department of Health, it can cause the following types of health problems:
Allergy and irritation
People with allergies may be more sensitive to mold than others. If they come into contact with mold, they may experience symptoms, such as:
- a runny or blocked nose
- watery, red eyes
- a dry cough
- skin rashes
- a sore throat
- sinusitis
- wheezing
Severe mold allergies cause more severe symptoms, including shortness of breath.
Mold exposure may also worsen asthma or lung problems in people with preexisting lung conditions.
A 2012 study found that infants and young children exposed to mold in the home had an increased risk of developing asthma by the age of 7. The research examined 289 homes and 36 types of mold.
However, S. chartarum was not among the three types of mold most strongly associated with asthma development.
Research published in 2004 by the Institute of Medicine (IOM) indicates that spending time in damp indoor spaces is related to respiratory symptoms, including those of asthma.
Infection
For most people with healthy immune systems, molds are not a problem.
However, people with weakened immune systems — such as those with uncontrolled HIV, transplant patients, or people undergoing cancer treatment — are at risk of fungal infections.
Toxic effects
Some people believe that black mold is particularly dangerous because it releases mycotoxins. However, the fact is that all molds are capable of producing mycotoxins. Just because mold is present does not mean that it is producing these toxins.
Most cases of mycotoxicosis result from eating moldy food, rather than from inhaling fungal spores in the home or outdoors. The evidence does not indicate that inhaling or touching mold can cause mycotoxicosis.
The IOM’s 2004 report was unable to back up claims that issues such as fatigue, lung disease, or cancer result from mold exposure.
The Centers for Disease Control and Prevention (CDC) state that there are very few reports of unique or rare health conditions resulting from mold in the home.
Summary
It appears that many types of indoor mold — not just black mold — may cause health problems in some people, but not in everyone.
Long term exposure to mold in the home, however, may be unhealthy for anyone.
People who are most at risk of the symptoms of mold exposure are:
- infants and children
- older adults
- people with allergies or asthma
- people with weakened immune systems
The main health concerns seem to relate to allergies and irritation, which typically cause respiratory symptoms.
People with weakened immune systems may also have a risk of fungal infection.
