Mold has different appearances depending on the species, stage of growth, and growth media. Often mold has a fuzzy or wooly appearance ranging in color from black, green and brown to yellow, gray and white. Fungi are a diverse group of single-celled organisms that includes mushrooms, molds, mildews, smuts, rusts, and yeasts. When the environment is favorable and the right amount of nutrients, moisture, and oxygen are present, mold can begin to grow. Indoor fungal contaminates can grow on different kinds of cellulose debris. Common indoor cellulose materials include:
- Wall paper
- Hard wood flooring
- Wood members
- Carpet Pad
- Tack Strip
It is estimated that there are over 400,000 different types of mold. Less than 100,000 have actually been named, of which less that 1,000 are commonly found indoors. Of all the molds found indoors, less than 1% are known to be toxic. That's the good news. The bad news is, without proper mold testing and laboratory analysis there is no way to know the difference. There are thousands of molds that are black, thousands that are green, thousands that are brown, etc… Direct microscopic analysis by highly trained and educated personnel is the only way to know for certain what types of molds are present and if fungal contamination is in an environment.
Molds are organized into three groups according to human responses: Allergenic, Pathogenic and Toxigenic.
Allergenic molds do not usually produce life-threatening health effects and are most likely to affect those who are already allergic or asthmatic. The human system responses to allergenic molds tend to be relatively mild, depending on individual sensitivities, typically producing scratchy throats, eye and nose irritations and rashes. These can lead to uncomfortable living for some if high amounts of allergenic molds are present.
Pathogenic molds usually produce some type of infection. They can cause serious health effects in persons with suppressed immune systems. Healthy people can usually resist infection by these organisms regardless of dose. In some cases, high exposure may cause hypersensitivity pneumonitis (an acute response to exposure to an organism).
Mycotoxins can cause serious health effects in almost anybody. These agents have toxic effects ranging from short-term irritation to immunosuppression and possibly cancer. Therefore, when toxigenic molds are found further evaluation and action is recommended.
Often, mold spores, whether dead or alive, cause adverse health effects, primarily of a respiratory nature, including hay fever-like allergic symptoms.
Some of these molds also produce chemical toxins known as "mycotoxins," which are generated and released into the air within the mold spores, leading to the "toxic mold" designation. Exposure to these toxins can occur through inhalation, ingestion, or skin contact, and can result in symptoms including dermatitis, cough, rhinitis, nose bleeds, cold and flu symptoms, headache, general malaise and fever.
Initial awareness of adverse health effects from Stachybotrys atra exposure was raised by a mid-1990's study from Cleveland, Ohio, involving infants who had died from sudden and unexplained pulmonary hemorrhage (bleeding of the lungs). Upon investigation, researchers found that the infants resided in homes with high levels of Stachybotrys atra were prone to serious health effects.
With the ongoing scientific research in to toxic mold species there are plenty of valid reasons for mold testing. For example, we now know that some molds produce toxins which may be linked to severe cases of asthma, respiratory problems including bleeding lungs, and many other very serious ailments including immune system disorders. The medical and legal communities are now taking mold contamination very seriously. With so much overwhelming evidence to support the dangers of exposure to mold, mold testing is the first step in properly assessing whether an abnormal or elevated mold condition exists.
There are a number of documented cases of health effects and physical problems resulting from indoor exposure to mold and mold spores. Mold related illnesses can result from high level / short-term exposures and lower level / long-term exposures. The most common health effects or symptoms reported from exposure to indoor mold environments are a chronic clearing of the throat, runny nose, eye irritation, cough, congestion, and aggravation of asthma, allergic reactions similar to cat allergies, headache, and fatigue. Mold related health effects are often reported as feeling like you have a cold but you don't. Eventually it may feel like you have the flu but you don't. Many of our customer report feeling better when they leave their home for a week or more. Once they arrive back within a day or so they are ill again.
Some individuals are at a higher risk of experiencing negative health affects from exposure to high amounts of mold or to certain types of mold. These include the following:
- Immune compromised individuals (cancer patients, etc)
- Pregnant women
- Individual’s with existing respiratory problems
- Individuals recovering from surgery
When elevated levels of airborne toxic mold spores are inhaled deep into the lungs of those sensitive they can sometimes enter the bloodstream and affect the immune system, nervous system, liver, kidneys, blood and cause brain damage. With enough long-term exposure to elevated mold environments, it is possible for mold related illnesses and health effects to become life-long chronic diseases.
Mycotoxins & Their Effect on the Human Body
The following information is written by Dr. Hildegarde Strininger and presented to the World Safety Organization's 17th International Environmental Safety & Health Conference & Exposition on November 3 - 5, 2003.
Aflatoxin is one of the most potent carcinogens known to man and has been linked to a wide variety of human health problems. The FDA has established maximum allowable levels of total aflatoxin in food commodities at 20 parts per billion. The maximum level for milk products is even lower at 0.5 parts per billion. Primarily Aspergillus species fungi produce aflatoxin.
Ochratoxin is primarily produced by species of Penicillium and Aspergillus. Ochratoxin is damaging to the kidneys and liver and is also a suspected carcinogen. There is also evidence that it impairs the immune system.
T-2 Toxin is trichothecene produced by species of Fusarium and is one of the more deadly toxins. If ingested in sufficient quantity, T-2 toxin can severely damage the entire digestive tract and cause rapid death due to internal hemorrhage. T-2 has been implicated in the human diseases alimentary toxi aleukia and pulmonary hemosiderosis. Damage caused by T-2 toxin is often permanent.
Fumonisin is a toxin associated with species of Fusarium. Fumonisisn is commonly found in corn and corn-based products, with recent outbreaks of veterinary mycotoxicosis occurring in Arizona, Indiana, Kentucky, North Carolina, South Carolina, Texas and Virginia. The animals most affected were horses and swine, resulting in dozens of deaths. Fumonisin toxin causes "crazy horse disease", or leukoencephalomalcia, a liquefaction of the brain. Symptoms include blindness, head butting and pressing, constant circling and ataxia, followed by death. Chronic low-level exposure in humans has been linked to esophageal cancer. The American Association of Veterinary Laboratory Diagnosticians (AAVLD) advisory levels for fumonisin is horse feed is 5 ppm.
Vomitoxin or Deoxynivalenol (DON)
Vomitoxin, chemically known as Deoxynivalenol, a tricothecene mycotoxin, is produced by several species of Fusarium. Vomitoxin has been associated with outbreaks of acute gastrointestinal illness in humans. The FDA advisory level for vomitoxin for human consumption is 1 ppm.
Zearalenone is also a mycotoxin produced by Fusarium molds. Zearalenone toxin is similar in chemical structure to the female sex hormone estrogen and targets the reproductive organs.
Citrinin is a nephrotoxin produced by Penicillium and Aspergillus species. Renal damage, vasodilatation, and bronchial constriction are some of the health effects associated with this toxin.
Alternariol cytotoxic compound derived from Alternia alternata.
Satratoxin H is a macrocyclic tricothecene produced by Stachybotrys chartaru, Trichoderma viridi and other fungi. High doses or chronic low doses are lethal. This toxin is abortogenic in animals and is believed to alter immune system function and makes affected individuals more susceptible to opportunistic infection.
Gliotoxin is an immunosuppressive toxin produced by species of Alternaria, Penicillium and Aspergillus.
Patulin is a mycotoxin produced by Penicillium, Aspergillus and a number of other genera of fungi. It is believed to cause hemorrhaging in the brain and lungs and is usually associated with apple and grape spoilage.
Sterigmatocystin is a nephrotoxin and a hepatotoxin produced by Aspergillus versicolor. This toxin is also considered to be carcinogenic. Other mycotoxins include: Penicillic acid, roquefortine, cyclopiazonic acid, verrucosidin, rubratoxins A and B, PR toxin, luteoskyrin, cychlochlorotine, rugulosin, erythroskyrine, secalonic acid D, viridicatumtoxin, kojic acid, xanthomegnin, viomellein, chaetroglobosin C, echinulin, flavoglaucin, versicolorin A, austamid, maltayzine, aspergillic acid, paspaline, aflatrem, fumagillin nigragilin, chlamydosporol, iscotrichodermin and many more. As previously discussed there are many mycotoxins that can cause adverse health effects and even death in humans. These synergistic effects of exposure to multiple mycotoxins simultaneously are very poorly understood. Even more poorly understood are the by-products of mycotoxin degradation, particularly under the influence of strong oxidizing agents such as sodium hypochlorite and/or ozone, agents frequently used or misused by hazardous materials personnel or remediation remediators in industry. More research is required in this field to better understand the relationship of fungal contamination, relative humidity, temperature and ventilation in fungal growth in buildings and on building substrates as they relate to disease.
Articles & Reference Links
For More Information on mold, please use the resources below:
Center for Disease Control and Prevention (CDC)
Environmental Protection Agency (EPA)
Washington State Dept of Health
California Renter's Rights with Property Mold