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Mold and Other Allergens

What Is Mold?

Most people think that mold is slimy, blackish-green discoloration found on carpeting, baseboards or wallpaper that is usually only found only in dirty, unkempt homes or apartments. The truth is, mold and spores can flourish in sparkling clean environments as well.

Molds are microscopic organisms that are found almost everywhere outdoors. No one really knows how many species of mold exist but estimates range from tens of thousands to hundreds of thousands. Molds reproduce by creating spores, which are small reproductive bodies that is capable of growing into a new organism, producing bacteria, fungi, and algae. Most spores are thread-like organisms so small that 250,000 of them can fit on the head of a pin. They stay airborne indefinitely, drifting from one room to the next, landing on food, clothing, appliances, table tops, carpeting and furniture, walls and woodwork. Any wet, damp or humid surface becomes a breeding ground for mold colonies and more spores.

You will find mold and mildew inside your sink and dishwasher cabinets and probably in your bathrooms and laundry areas. In fact, there is an 86% chance of mold growing somewhere in or on your refrigerator. Its nestled into the microscopic crevices of clothing, furniture fabric and in your carpeting. There is little doubt that mold spores exist in your heating and air conditioner system ductwork, window sills, basement, crawl space and attic, office desk, indoor plants, kitchen counter space, on the TV, in your fireplace and countless other places.

Many of these locations could contain everyday, ordinary “low-risk” and “acceptable level” occurrences of mold—or not. Each person has their own level of tolerance to the mycotoxins (poisons) emitted by mold. And those with higher levels of tolerance to mycotoxins can eventually become sensitized to these poisons from prolonged exposures. The “higher risk” mold conditions can usually be recognized by the sudden visual appearance of emerging mold, or the presence of a pungent mildew or musty odor. The faintest whiff of this odor should immediately prompt your concern about mold exposure and prompt you to take quick action to identify and correct its cause and clean up the mold and mildew damage!

Pathogenic Molds

Pathogenic molds usually produce some type of infection. (Pathogenic literally means, “capable of causing disease”.) While a normal, healthy individual can probably resist infection by these organisms regardless of dose, pathogenic molds can cause serious health effects in persons with suppressed, underdeveloped, or compromised immune systems. In some cases, high exposure may cause hypersensitivity pneumonitis (an acute response to exposure to an organism). People with compromised immune systems would be, infants and small children whose immune systems are not fully developed, elderly people whose immune systems are essentially worn out, and anyone exposed to AIDS, chemotherapy, pneumonia, bronchitis, and other respiratory infections.

Toxic Molds

“Black Mold” is a term commonly used to describe molds that are black and slimy. It is also often used in reference to toxic mold; molds that are know to present health risks to humans and animals by producing Mycotoxins (poisons). Mycotoxins are fungal metabolites that have been identified as toxic agents.

However, that not all black mold is toxic and that not all toxic mold is black. In fact, there are over 400,000 different types of mold and many of them are black in color of which only a portion have been identified. Black mold and/or toxic mold are terms often used in reference to Stachybotrys, (stack-ee-bot-ris) aka: Stachybotrys chartarum, aka: Stachybotrys atra. Many fungi (e.g., species of Aspergillus, Penicillium, Fusarium, Trichoderma, and Memnoniella) in addition to Stachybotrys can produce potent mycotoxins, some of which are identical to compounds produced by Stachybotrys.

Mold Allergies

Along with pollens from trees, grasses, and weeds, molds are another cause of seasonal allergic rhinitis. People allergic to molds may have symptoms from spring to late fall, often peaking from July to late summer. Unlike pollens, molds may persist after the first killing frost and some can even grow at subfreezing temperatures, but most become dormant. Snow cover lowers the outdoor mold count dramatically but does not kill molds. After the spring thaw, molds thrive on the vegetation that has been killed by the winter cold.

Those living in the warmest areas of the United States will find molds thriving all year-round, thus causing constant allergic problems. In addition, molds growing indoors can cause year-round allergic rhinitis even in the coldest climates.

When the microscopic fungal spores or fragments of fungi, are inhaled they may cause allergic rhinitis. Being so small, mold spores may evade the protective mechanisms of the nose and upper respiratory tract to reach the lungs.

Which Molds are Allergenic?

Like pollens, mold spores are important airborne allergens only if they are abundant, easily carried by air currents, and allergenic in their chemical makeup. Found almost everywhere, mold spores in some areas are so numerous they often outnumber the pollens in the air. Fortunately, however, only a few dozen different types are significant allergens.

In general, Alternaria and Cladosporium (Hormodendrum) are the molds most commonly found both indoors and outdoors throughout the United States. Aspergillus, Penicillium, Helminthosporium, Epicoccum, Fusarium, Mucor, Rhizopus, and Aureobasidium (Pullularia) are also common.

Many weather forcasts now also contain mold counts in addition to pollen counts information. However, for several reasons these counts shouldn’t be used as a constant guide for daily activities. One reason is that the number and types of spores actually present in the mold count may have changed considerably in 24 hours because weather and spore dispersal are directly related. Many of the common allergenic molds are of the dry spore type–they release their spores during dry, windy weather. Other fungi need high humidity, fog, or dew to release their spores. Although rain washes many larger spores out of the air, it also causes some smaller spores to be shot into the air. In addition to the effect of day-to-day weather changes on mold counts, spore populations may also differ between day and night. Day favors dispersal by dry spore types and night favors wet spore types.

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