What is black mold?

Mold is a vital part of our ecosystem. It absorbs and decomposes organic matter. Mold grows anywhere that the conditions are right. It needs adequate moisture, a food source, oxygen, and an appropriate temperature to grow. If these conditions are present, then mold will grow and reproduce by releasing spores, which are microscopic cells that act like seeds, into the environment.
While mold plays an important role outside, when it grows inside buildings, it can cause health problems for some people. When people talk about black mold, they are usually referring to Stachybotrys chartarum, which has been referred to as "toxic black mold." However, there is no evidence to suggest that the color of mold affects how dangerous it is.
There is also no evidence that exposure to any type of mold causes memory loss, trouble focusing, headaches, fatigue, autoimmune disease, or infant pulmonary hemorrhage, which is bleeding into the lungs.
Some molds do produce mycotoxins, which are toxic substances. However, mycotoxins are most harmful when they are eaten, not inhaled. Although the threat of black mold has been overhyped in the media, mold can cause health problems in people who are sensitive to it. Mold should always be properly treated and removed from buildings using adequate precautions.
Symptoms of black mold exposure
Many types of indoor mold, not just black mold, can cause symptoms if you are sensitive to them or are exposed to them for a prolonged period of time. Symptoms of mold exposure include:
- Sneezing
- Coughing
- Wheezing
- Nasal congestion
- Skin rashes
- Sore throat
- Eye irritation
Symptoms of mold exposure may be worse in people who are most at risk, including:
Causes of mold
Mold will grow anywhere the humidity exceeds 70% and can be active if the humidity is at 60% or higher. Mold also grows very quickly. Mold will grow within 24 to 48 hours on a damp surface.
Mold thrives in any warm, dark, and moist environment. The most common causes of mold in buildings are water leaks, condensation, and floods. Poor ventilation can also cause mold. Rooms such as the kitchen and bathroom, where water is frequently used, can easily grow mold if not properly ventilated.
Types of mold
There are thousands of types of mold, but the most common types of mold found indoors include:
- Cladosporium
- Penicillium
- Aspergillus
- Alternia

SLIDESHOW
Common Allergies: Symptoms and Signs See SlideshowWhen to see the doctor for mold exposure
If you're having symptoms of mold exposure, you may want to see your doctor or allergist to find out if you're allergic to mold. Your doctor can perform tests to determine if you have a mold allergy and recommend a treatment plan.
Diagnosing mold exposure
Your doctor will take a medical history that includes your signs and symptoms. They may do a physical exam and perform the following tests:
Skin prick test
In this test, you are given tiny pricks containing diluted amounts of substances you may be allergic to. If you are allergic, you will develop a small hive around the area of the prick.
Blood test
In this test, also called the radioallergosorbent test (RAST), a sample of your blood is tested for certain antibodies, which can determine if you are allergic to specific types of mold.
Treatment for mold exposure
The most important treatment for indoor mold exposure is to fix and remove the source of the mold. Limiting your exposure to mold is the most effective way to eliminate symptoms. If you remove the mold yourself, you need to take appropriate precautions to prevent exposure. You can also contact a mold remediation company to remove it for you.
Nasal sprays
These sprays, which contain corticosteroids or decongestants, are generally well tolerated and effective. They work by reducing the inflammation caused by allergies. Some can be bought over-the-counter, and some are only available by prescription.
Allergy medications
Over-the-counter allergy medications such as cetirizine or loratadine are often used to treat allergies. These are antihistamines that work by blocking histamine, a chemical released by your immune system in response to allergens.
Montelukast is a prescription allergy medication that works by blocking another chemical released by your immune system, leukotrienes.
Sinus rinses
Rinsing your sinuses with saline water can help flush away allergens and mucus from your sinus cavities. This will help keep your nose free of irritating substances that can cause bothersome symptoms. These kits are widely available over the counter.
Allergy shots
Allergy shots, also called immunotherapy, expose you to a small amount of an allergen to build up your immunity over time. These can be effective for certain types of mold allergy.
Centers for Disease Control and Prevention: " Facts about Stachybotrys chartarum."
Clinical Reviews in Allergy and Immunology: "Mold and Human Health: A Reality Check."
Clinical Reviews in Allergy and Immunology: "The Myth of Mycotoxins and Mold Injury."
Indoor Air: "Indoor mold levels and current asthma among school-aged children in Saskatchewan, Canada."
Institute of Medicine (US) Committee on Damp Indoor Spaces and Health. Damp Indoor Spaces and Health. National Academies Press. 2004
Integrated Medicine: A Clinician's Journal: "Is Mold Toxicity Really a Problem for Our Patients? Part 1 - Respiratory Conditions."
Mayo Clinic: "Mold Allergy."
National Institute of Environmental Health Sciences: "Mold."
Virginia Cooperative Extension: "Mold Basics."
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