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Mold is a fungus that grows in the form of hyphae, or short branches of interconnected cells. Over 100,000 species of molds have been identified and named, and about a tenth of these can be found indoors on fabrics, food or even walls. Typically, mold thrives in dark, damp spaces. Household mold is generally categorized into allergenic, pathogenic, and toxigenic.
Household mold is microscopic in size, and hundreds of thousands of spores can fit onto the head of a pin. When mold reproduces and forms large interconnected strands of hyphae, called a colony, it can become visible to the human eye. Household mold is generally green or black in color, with black mold being potentially dangerous. Mildew is the same as mold, and it is commonly found in areas that are exposed to damp conditions.
Allergenic molds are generally harmless, but can cause reactions in some people with allergies or asthma. These molds are similar to pollen, in that they are airborne and plentiful in the right environment. Sometimes a mold count in the air at any one time can be higher than a pollen count. Examples of allergenic molds are Alternaria, Cladosporium, Mucor, Aspergillus and Penicillium. Allergenic molds should not be ignored, because they can become toxic when the colony is large enough.
Pathogenic molds are less common, and can cause infection. People with normal immune systems can usually ward off this type of infection, but those with a compromised immune system could be at risk. This includes people with HIV/AIDS, people with pneumonia, infants or small children. The most common species of pathogenic household mold is Bipolaris.
Toxigenic molds are referred to as black mold. Not every mold that is black is toxic, however. Toxigenic molds are highly dangerous and can cause severe problems. The most common type of toxigenic mold is Stachybotrys, which produces mycotoxins that act as toxic agents.
Side effects of allergenic molds are usually those associated with allergies in general: runny nose, itchy, watery eyes, etc. Some molds can produce headaches or dizziness. Dangerous molds, or a high exposure to otherwise-harmless molds, can result in critical damage to any number of internal organs or systems. Once toxic mold enters the body, it can attach itself to an organ and begin to reproduce, consuming the organ in the most severe cases.
There are many types of household mold detecting kits available. These tests typically require a sample of the mold to be shipped to a laboratory for analysis and possible identification. Most tests are affordable, but lesser-expensive tests are not as comprehensive and may not identify the mold type found in the home. One can also pay for a mold inspector who will examine a home for mold and report the findings of laboratory analysis.