Allergy and irritation are the most common symptoms of mold exposure. Less common effects of mold exposure include infections and diseases. Serious infections caused by mold are relatively rare and occur mainly in people with severely weakened immune systems. Exposure to humid, musty environments can cause a variety of health effects, or none at all.
Some people are sensitive to mold. For these people, exposure to mold can cause symptoms such as nasal congestion, wheezing, and redness or itching of the eyes or skin. Some people, such as those with mold allergies or asthma, may have more intense reactions. Serious reactions can occur among workers exposed to large amounts of mold in work environments, such as farmers who work near moldy hay.
Serious reactions may include fever and shortness of breath. Molds aren't usually a problem indoors, unless mold spores land in a wet or humid place and begin to grow. Molds have the potential to cause health problems. Molds produce allergens (substances that can cause allergic reactions), irritants and, in some cases, potentially toxic substances (mycotoxins).
Inhaling or touching mold or mold spores can cause allergic reactions in sensitive people. Allergic responses include symptoms similar to those of hay fever, such as sneezing, runny nose, red eyes, and skin rashes (dermatitis). Allergic reactions to mold are common. They can be immediate or delayed.
Mold can also cause asthma attacks in people with asthma who are allergic to mold. In addition, exposure to mold can irritate the eyes, skin, nose, throat, and lungs of people who are allergic and non-allergic to mold. Symptoms other than the allergic and irritant types usually do not occur as a result of inhaling mold. Research on mold and its health effects is ongoing.
This brochure provides a brief overview; it does not describe all the possible health effects related to exposure to mold. For more detailed information, consult a health professional. You can also check with your state or local health department. The most common types of mold are Aspergillus, Cladosporium, and Stachybotrys atra (also known as black mold).
Aspergillus is a highly allergenic mold that is commonly found in food and household air conditioning systems. Cladosporium is usually a black or green substance similar to “pepper” that grows on the backs of toilets, painted surfaces, and fiberglass air ducts. While this mold isn't toxic to humans, it can cause common allergy symptoms, such as red, watery eyes, rashes, and sore throats. Because mold grows in humid conditions, it's not enough to solve moisture problems by drying out the wall and areas where mold is present.
If you discover mold near drains, water pipes, or any other plumbing fixtures in your home, this indicates that the mold is somewhere near the leak. If you are allergic to mold and also asthmatic, you should have a contingency plan for emergency situations, as reactions can be serious. Other recent studies have suggested a possible relationship between early exposure to mold and the development of asthma in some children, especially among children who may be genetically susceptible to the development of asthma, and that certain interventions to improve housing conditions may reduce the morbidity caused by asthma and respiratory allergies. A study suggests that up to 90 percent of chronic nasal problems can be attributed to mold in the home or workplace.
These types of mold and mildew can discolor the roof and damage the roof tiles for a period of time if left unattended. Mold can sometimes be a warning sign of a costly moisture problem, such as wood decay inside ceilings or walls. When mold spores fall in places where there is excess moisture, such as when there have been leaks in roofs, pipes, walls, pots, or where there has been flooding, they will grow. Most people may only experience an allergic reaction or allergy-like symptoms after exposure to mold.
These case reports are rare and a causal relationship between the presence of toxigenic mold and these conditions has not been demonstrated. It's important to properly clean and dry the area, as you can still have an allergic reaction to parts of the dead mold and mold contamination can recur if there's still a source of moisture. Once the moisture dries, clean and spray the area with an antimicrobial treatment to prevent mold from reappearing. Mold in outdoor air can also stick to clothing, shoes, and pets can be brought indoors.
In areas where mold tends to grow, such as basement walls, spray or paint the walls with a mold-resistant primer or add Mildewcide to the paint. .
