How can molds affect people?

Molds produce health effects through inflammation, allergy, or infection. Allergic reactions (often referred to as hay fever) are most common following mold exposure. Typical symptoms that mold-exposed individuals report (alone or in combination) include:

Office workers and people in their homes sometimes complain of these symptoms. This may be an indication to have the building inspected for fungal growth.

How much mold can make me sick?

It depends. For some people, a relatively small number of mold spores can trigger an asthma attack or lead to other health problems. For other individuals, symptoms may occur only when exposure levels are much higher. Those who are especially at risk are: those with existing asthma conditions, infants, the elderly and any other immune compromised individuals.

Molds and Health

Mold exposure indoors does not always present a health problem. But some people, are sensitive to mold and can suffer allergic reactions (including, but not limited to) nasal stuffiness, eye irritation, or wheezing. Some individuals with chronic respiratory diseases may experience difficulty breathing, may develop mold infections in their lungs, and should consult a doctor for diagnosis and treatment.

Workers exposed to large amounts of mold, like farmers working around moldy hay, may suffer severe reactions, including fever and shortness of breath.

The Centers for Disease Control and Prevention suggest sensitive people should limit their exposure to certain outdoor areas that are likely to have mold, such as compost piles, cut grass, and wooded areas.

A more clinical description of Health Effects

Molds produce acute health effects through toxin-induced inflammation, allergy, or infection. There is no information at this time on the effects of chronic, low dose inhalation exposure to mycotoxins.

Toxin-induced inflammation: Repeated or high exposures to airborne mycotoxins can cause mucous membrane irritation characterized by eye, nose and throat irritation (Richerson, 1990). When small diameter spores (2-4 µm) are inhaled, they may reach the lung alveoli and induce an inflammatory reaction, creating toxic pneumonitis. Severe toxic pneumonitis can cause fever, flu-like symptoms and fatigue (organic toxic dust syndrome). Hypersensitivity pneumonitis, a particular form of glaucomatous lung disease, is a syndrome caused by inhalation of large concentrations of dust containing organic material including fungal spores. It is generally an occupational hazard in agriculture, but has been reported in individuals exposed in the home (Flannigan, et al., 1991). Other symptoms attributed to mycotoxin or fungal-originating VOCs include headache, dizziness, dermatitis, diarrhea and impaired or altered immune function.

Allergy: Indoor fungal allergens probably affect fewer people than do allergens from cats, mites or cockroaches. Yet a significant proportion (10-32%) of all asthmatics are sensitive to fungi.

Infection: Opportunistic fungal pathogens, such as Aspergillus, are common in indoor air. A normal, healthy individual can probably resist infection by these organisms regardless of dose, although high exposures may cause hypersensitivity pneumonitis. However, any mold that can grow at body temperature can become a pathogen in an immune compromised host. Individuals undergoing chemotherapy, organ or bone marrow transplantation or those with HIV/AIDS are especially susceptible to invasive infection by Aspergillus species (aspergillosis: a disease caused by Aspergillus).

Here is more information from the Center for Disease Control (LINK):

For further clinical studies, SEE journal article written by Berlin D. Nelson, Professor, Department of Plant Pathology, North Dakota State University, Fargo.