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Environmental Health - Information - Mold


Molds are fungi that grow throughout the natural and built environment. Tiny particles of mold are always present in indoor and outdoor environments. In nature, molds help break down dead materials and can be found growing on soil, foods, plant matter, and other items. Molds produce microscopic cells called "spores" which are very tiny and spread easily through the air. Live spores act like seeds, forming new mold growths (colonies) when they find the right conditions. Mold needs moisture, nutrients and a suitable location in order to grow and multiply.

Click on each topic below for more information on mold

Are air cleaners that use ozone safe and effective?

According to the Environmental Protection Agency (EPA) publication Residential Air-Cleaning Devices: A Summary of Available Information, "Some air cleaners, under the right conditions, can effectively remove small particles which are suspended in air. However, controversy exists as to the efficacy of air cleaners in removing larger particles such as pollen and house dust allergens, which rapidly settle from indoor air.

In assessing the ability of an air cleaner in removing allergens, one should consider the relative contribution of airborne to surface concentrations of the allergens, particularly in the case of pollen and house dust allergens where natural settling may be so rapid that air cleaners contribute little additional effect. Animal dander may settle more slowly, although, again, the surface reservoir far exceeds the amount in the air.

Furthermore, control of the sources of allergens and, where allergens do not originate outdoors, ventilation should be stressed as the primary means of reducing allergic reactions." Consumers who have employed source control and ventilation to reduce contaminants, and who choose to add air cleaning as well, should refer to either of these publications:

  • Residential Air-Cleaning Devices: A Summary of Available Information,
    from EPA
  • Air Cleaners, from Rutgers Cooperative Extension

This is a summary of the EPA document, Ozone Generators that are Sold as Air Cleaners. Ozone generators that are sold as air cleaners intentionally produce the gas ozone. Contrary to the claims of some vendors, no agency of the federal government has approved these devices for use in occupied spaces. In fact, when ozone is inhaled, it can damage the lungs. Relatively low amounts can cause chest pain, coughing, nausea, throat irritation, and congestion. It may also worsen bronchitis, heart disease, emphysema, and asthma, and can compromise the ability of the body to fight respiratory infections.

Although manufacturers and vendors of ozone generators may describe ozone as "energized oxygen" or "pure air," ozone is a toxic gas with different properties from oxygen. In fact, several federal agencies have established health standards or recommendations to limit human exposure to ozone. Scientific studies have shown that when ozone concentrations do not exceed these public health standards, ozone has little potential to remove indoor air contaminants. Particles such as dust and pollen that cause allergies are not removed by ozone. Ozone is also not effective at removing many odor-causing chemicals, nor does it remove viruses, bacteria, mold, or other biological pollutants. Some studies show that ozone concentrations produced by ozone generators can exceed health standards even when the manufacturer's instructions are followed.

High concentrations of ozone are sometimes used to help decontaminate unoccupied spaces from certain chemical or biological contaminants or odors, but these should only be used when people are not present. At these high concentrations, ozone can be toxic to human health and adversely affect indoor plants, and damage materials such as rubber, electrical wire coatings, and fabrics and art work containing susceptible dyes and pigments.

The public is advised to use proven methods of controlling indoor air pollution such as: eliminating or controlling pollutant sources, increasing outdoor air ventilation, and using safe, effective methods of air cleaning.

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Can mold make me sick?

Mold can affect the health of people who are exposed to it. Exposure occurs primarily by breathing spores or other tiny fragments. Exposure can also occur through skin contact (for example, by touching moldy surfaces) and by swallowing it. The type and severity of health effects that mold may produce are difficult to predict. The risks can vary greatly from one location to another, over time, and from person to person. People having mold reactions often report problems such as: nasal and sinus congestion; cough; wheeze/breathing difficulties; sore throat, skin and eye irritation and upper respiratory infections (including sinus). On rare occasions, more serious problems can develop. Mold-related symptoms typically disappear when the mold is eliminated from the indoor environment.

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Does cleaning the ductwork in the home reduce indoor air contamination?

The Environmental Protection Agency (EPA) has this to say about duct cleaning: "Duct cleaning has never been shown to actually prevent health problems. Neither do studies conclusively demonstrate that particle (e.g., dust) levels in homes increase because of dirty air ducts. This is because much of the dirt in air ducts adheres to duct surfaces and does not necessarily enter the living space.

It is important to keep in mind that dirty air ducts are only one of many possible sources of particles that are present in homes. Pollutants that enter the home both from outdoor and indoor activities such as cooking, cleaning, smoking, or just moving around, can cause greater exposure to contaminants than dirty air ducts. There is no evidence that a light amount of household dust or other particulate matter in air ducts poses any risk to your health.

You should consider cleaning the air ducts in your home if:

  • There is substantial visible mold growth present in hard surface (e.g. sheet metal) ducts or on other components of your heating and cooling system
  • Ducts are infested with vermin (e.g. rodents or insects)
  • Ducts are clogged with excessive amounts of dust and debris and/or particles are actually released into the home from your supply registers.

If any of the conditions above exist, try to find the cause or causes and correct them or else the problem will likely recur.

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Does the Volusia County Health Department test for mold?

The Volusia County Health Department does not typically conduct mold testing in our investigations. There are no standards for molds in living and working environments, so it’s very difficult to interpret testing results. If the mystery material in your house looks or smells like mold, it probably is. Don’t continue to expose yourself waiting for a mold test. It is important to protect your health and property by stopping the moisture causing the growth and eliminating mold from the house as soon as possible. If you absolutely must know what that black slime is on your wall, it is recommend that a lab with Environmental Microbiology Laboratory Accreditation Program (EMLAP) certification from the American Industrial Hygiene Association be used.

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How do I know if I have a mold problem?

The most practical way to find a mold problem is by using your eyes to look for mold growth and your nose to locate the source of a suspicious odor. If you see mold or if there is an earthy or musty smell in your indoor environment, you should assume a mold problem exists. Look for visible mold growth (may appear cottony, velvety, granular, or leathery and have varied colors of white, gray, brown, black, yellow, green). Mold can also appear as a discoloration, staining, or fuzzy growth on the surface of building materials or furnishings. Mold typically appears where there is excess moisture or water damage such as near plumbing/roof leaks, foundation seepage and condensation areas (wall cavities/windows). Search behind and underneath materials (carpet and pad, wallpaper, vinyl flooring, sink, and cabinets), furniture, or stored items (especially things placed near outside walls or on cold floors). Sometimes destructive techniques may be needed to inspect and clean enclosed spaces (such as a wall cavity) where mold and moisture are hidden.

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How do I solve a mold problem?

The critical step in solving mold problems is removing the moisture source and removing contaminated materials. Repair of the defects that led to the moisture problem should be conducted in conjunction with fungus removal. Once the moisture source has been eliminated, building materials supporting fungal growth must be remediated as rapidly as possible. Specific methods of assessing and remediating fungal contamination should be based on the extent of visible contamination and underlying damage. The simplest and most expedient remediation that is reasonable and properly and safely removes fungal contamination, should be used.

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Is vacuuming an effective way to remove biological contaminants that have settled onto surfaces?

Research has shown that vacuuming can cause anywhere between a 35 to 98 percent increase in airborne particulate levels. Since the vacuum cleaner filter bag can only retains larger particles, smaller ones can pass through it and into the room air. Particles smaller than 20 microns in size (about one-half the diameter of the finest human hair) may remain suspended in the air for significant time periods. Some portable vacuum cleaners are designed with high efficiency particulate air (HEPA) filters that remove at least 99.97 percent of the smallest particles in the discharge air. A central vacuum system may offer an advantage over portable units because it can have more suction to remove embedded materials and can direct exhaust air outside of the house. If you or someone in your family has allergies, it is important to use a vacuum cleaner that does not cause those particulates to become airborne and can remove them from your indoor environment.

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Mold/Moisture Resources on the Internet

You will find numerous webpages on the subject of mold, some providing more factual information than others. The Volusia County Health Department recommends you gather your information from state and federal health agency web pages. Below you will find links for additional information. Inclusion on this list does not indicate that we fully agree with the entire contents of the page cited.

U.S. Environmental Protection Agency

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What is toxic black mold?

The term “toxic black mold” is typically used by the media to describe the mold Stachybotrys. It is one of many molds that can appear black. Stachybotrys gained much attention and was labeled “toxic” by the media when the mycotoxin it produces was implicated in the development of acute pulmonary hemorrhage/hemosiderosis in infants. However, a review of these cases by the Centers for Disease Control and Prevention (CDC) could not prove that an association ever existed. Molds selectively make and use mycotoxins to repel competitors and gain control of a food source. The presence of certain molds (such as Stachybotrys) is no guarantee that a mycotoxin will be found. Mycotoxin-producing molds can also be many different colors, including black. Considerable gaps of understanding exist in the scientific community as to what, if any, health effects, mycotoxins cause in indoor environments. Despite this uncertainty, the allergenic effects of mold are well documented. Indoor growth should be removed and the conditions that caused such growth be eliminated regardless of the color or type of mold or its ability to make mycotoxins.

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Page last updated: 07/9/13