FACTS ABOUT MOLD, AND HOW WE CONDUCT TESTS TO DETERMINE MOLD LEVELS
Scope of Remediation/Restoration:
The word "sample"
means different things in different contexts. At times, investigators
use the term to designate an individual measurement (e.g., an air or
source sample). However, a sample may also designate a set of measurements
(e.g., multiple measurements of some parameter that comprise a sample
of size n). In either case, the goal of sampling is to learn about entire
populations by looking at subsets of the members of the population.
There are several types of testing methods that can detect the presence
of mold. They can be used to find mold particles which are suspended
in air, in settled dust, or growing on surfaces of building materials
and furnishings. Some methods can identify a portion of the types of
live molds in a sampled environment.
A brief introduction into how Laser Particle Counters work is in order here, to understand why they are useless for mold investigations.
A Laser Particle Counter consists of three basic components: 1) An isokinetic probe that is used to extract air into the device, 2) A laser beam generation device with receiver plate where the particles pulled into the device from the isokinetic probe break the beam, 3) Software or electromechanical circuitry to assess the size of the particles, and count the particles that are within a certain size range.
Given this basic description of the components of a laser particle counter, there is no way that a laser particle counter can determine anything about a particle other than it's diametric size. A laser particle counter provides no means whatsoever to determine if a particle that enters its chamber is dust, pollen, skin cells, mold, insulation particles, or any other thing. Given this fact, one might ask what the purpose is of a laser particle counter?
Laser Particle Counters were first developed as a means to efficiently assess and determine the clarity of refined liquids. They are very useful to determine the amount and size of solid contaminants in gasoline, refined liquid foods, etc. Then, Industrial Hygienists discovered that Laser Particle Counters were a tool to be added to a box of tools that will let them know how much particulate "stuff" was in the air when they perform an Indoor Air Quality investigation (Note: An Indoor Air Quality investigation is NOT at all the same thing as a mold investigation). A related application to this is in computer chip clean rooms, where the manufacturer doesn't care what the substance is that is in the air, any substance settling on the chip plate would ruin it.
Given that Laser Particle Counters cannot inform the operator "what" is in the air, just "how much" and "what size" of "stuff" is in the air, a reasonable question is: "Why are mold inspectors using Laser Particle Counters for mold investigations and Clearance testing?". Giving them the benefit of the doubt, the answer is: They don't know better. If you don't want to given them the benefit of the doubt, you can draw your own conclusions why a mold inspector would be motivated to tell you that you have a mold contamination problem, when all you might have is dust, pollen, etc.
The American Council of Government Industrial Hygienists (ACGIH) does not recommend the use of Laser Particle Counters for mold investigations. The reason: It is impossible to determine the genus or concentration of mold using a Laser Particle Counter.
Surface sampling can be useful
for differentiating between mold growth and stains, for identifying
the type of mold growth that may be present and, in some instances,
identifying signs of mold growth in a general vicinity. Surface sampling
can improve the accuracy of the results and interpretation of the inspected
environment if sampled correctly, although not required. The following
are the different types of surface samples that are commonly used to
perform a direct
Tape (or tape-lift):
These samples can be collected using clear adhesive tape or packing tape. For microscopic examination of collected particles, adhesive tapes must be of good optical quality and compatible with any stains the analytical laboratory may use on the specimens. Easily removed material is collected by touching the tape gently to a test surface and removing the tape with a steady force.
Air samples are possibly the
most common type of environmental sample that investigators collect
to study bioaerosols. The physics of removing particles from the air
and the general principles of good sample collection apply to all airborne
materials, whether biological or other origin. Therefore, many of the
basic principles investigators use to identify and quantify other airborne
particulate matter can be adapted to bioaerosol sampling. Common to
test identifies dangerous molds & mildew.. Lab analysis is provided
to indicate the exact count and type of mold & mildew present.
The term "data" can vary and may consist of the simple observation of fungal growth on a wall, analytical measurements from hundreds of environmental samples, or the results of a survey of building occupants with and without particular building-related conditions.
Data interpretation is the
process whereby investigators make decisions on (a) the relevance to
human exposure of environmental observations and measurements, (b) the
strength of associations between exposure and health status, and (c)
the probability of current or future risks. These interpretation steps
are followed by decisions on what measures can be taken to interrupt
exposure and prevent future problems.
Prevention of mold growth indoors is only possible if the factors that may allow it are identified and controlled. When prevention has failed and visible growth has occurred in a home or building, restoration requires (a) removal of porous materials showing extensive microbial growth, (b) physical removal of surface microbial growth on non-pourous materials to typical background levels, and (c) reduction of moisture to levels that do not support microbial growth.
Identification of the conditions
that contributed to microbial proliferation in a home or building is
the most important step in remediation. No effective control strategy
can be implemented without a clear understanding of the events or building
dynamics responsible for microbial growth.
Potential health effects and symptoms associated with mold exposures
include allergic reactions, asthma, and other respiratory problems.
The most common symptoms of mold exposure are runny nose, eye irritation, cough, congestion, and aggravation of asthma.
Individuals with persistent health problems that appear to be related to mold or other types of air quality contaminant exposure should see their physicians for a referral to professionals who are trained in occupational/environmental medicine or related specialties and are knowledgeable about these types of exposures. Decisions about removing individuals from an affected area must be based on the results of such medical evaluation.
Since mold is naturally present
in outdoor environments and we share the same air between the indoors
and the outdoors, it is impossible to eliminate all mold and their spores
The mold identified in lab reports are often associated with excess moisture and can be a problem in indoor environments at high levels. Since mold requires water to grow, it is important to prevent moisture problems in buildings. The presence of mold, water damage, or musty odors should be addressed immediately. In all instances, any source(s) of water must be stopped and the extent of water damage determined. Mold can grow on virtually any organic substance, as long as moisture and oxygen are present.
When excessive moisture accumulates
in buildings or on building materials, mold growth will often occur,
particularly if the moisture problem remains undiscovered or unaddressed.
Building materials, such as drywall are made of cellulose and are highly
absorbent, perfect surfaces for mold growth when wet. Moisture problems
may include roof leaks, plumbing leaks, landscaping or gutters that
direct water into or under the building, and unvented combustion appliances
such as gas stoves. Water damaged building materials supporting mold
growth should be cleaned or replaced as quickly as possible in order
to ensure a healthy environment. Specific methods of assessing and remediating
mold contamination should be based on the extent of visible
"Fifty percent [50%] of homes
contain problem molds.
A new medical study attributes nearly 100% of chronic sinus infections to mold. A 300% increase in the asthma rate over the past 20 years has been linked to molds," as reported in USA WEEKEND, December 3-5, 1999.
"Exposure to certain types of fungi, known as toxic mold, can cause a serious [allergic] reaction, or death. If you're unlucky, this is the kind of mold you have. If you're really unlucky, your toxic mold will gird for battle and go to war, secreting chemicals called mycotoxins, which can find their way into your body, entering through your nose, mouth, and skin, lodging perhaps in your digestive tract, your lungs, or your brain. Among these toxins are trichothecenes, which were rumored to have been used as a biological weapon during the wars in Afghanistan and Vietnam," warned Lisa Belkin, "Haunted by Mold," NEW YORK TIMES, August 13, 2001.
can cause hearing loss, vomiting, memory loss
"All molds have the potential to cause health effects. Molds can produce allergens that can trigger allergic reactions or even asthma attacks in people allergic to mold. Others are known to produce potent toxins and/or irritants. Potential health concerns are an important reason to prevent mold growth and to remediate/clean up any existing indoor mold growth."
-- U.S. Environmental Protection Agency, 03/01.
"Most homeowners believe that as long as they do not see visible signs of mold, that is, patches of green, blue, or black discoloration on surfaces, their environment is free of contamination. What they don't realize, however, is that large accumulations of [hidden or concealed] mold may be growing in areas that they cannot see, like air ducts, remote attic or basement spaces, or wall cavities. Left to multiply, these infestations may produce enough organic compounds to cause allergic reactions, sickness and, in extreme cases, death (a possibility with infants)."
-- Edward R. Lipinski, HOME CLINIC: The Battle Against Mold and Mildew, NEW YORK TIMES, Sept. 12, 1999.
"All molds have the
potential to cause health effects.
Molds can produce allergens that can trigger allergic reactions or even
asthma attacks in people allergic to mold. Others are known to produce
potent toxins and/or irritants. Potential health concerns are an important
reason." The U.S. Environmental Protection Agency, March, 2001.
Health-care professionals now know that molds can cause allergies, trigger asthma attacks and increase susceptibility to colds and flu. Anyone with a genetic predisposition can become allergic if exposed repeatedly to high enough levels.
Dr. David Sherris at the Mayo Clinic performed a study of 210 patients with chronic sinus infections and found that most had allergic fungal sinusitis. The prevailing medical opinion has been that mold accounted for 6 to 7 percent of all chronic sinusitis. [The Mayo Clinic study] found that it was 93 percent-the exact reverse. [Newsweek, 12/4/00]
Asthma and Mold
For millions of Americans, taking a breath is a major task. The culprit, asthma, affects more than 17 million Americans, including five million children. Asthma is a chronic disease in which air flow in and out of the lungs is impeded by swelling, constriction, and inflammation of the bronchial tubes, as was well as excess mucus production within those tubes. The airways of all people constrict when exposed to certain irritants like pollen, pollutants or some drugs. People without asthma can usually make the airways relax again quickly just by taking deep breaths. People with asthma cannot do that.
Patients may find their condition triggered or worsened by several factors, which can be allergic or non-allergic in nature. Allergic asthma means that asthma symptoms become more intense, perhaps even result in an asthma attack, when the individual is exposed to allergens to which their immune system is sensitive. The inflamed airways of asthmatics are sometimes described as twitchy, and inhaling pollens, molds, animal dander or other allergens can cause the airways to become even more inflamed, produce mucus & constrict. Most asthma in children is allergic in nature. From American. Academy. of Allergy, Asthma & Immunology [U.S.A. Today, All About Allergies & Asthma, 3/16/01]
Alzheimer's and Mold
Because the effects of toxic mold (Stachybotrys) are similar to Alzheimer's Disease [in such ways as the loss of memory and ability to think logically], it is possible that relatives and friends of toxic mold victims think that their relative's memory losses and mental diminishment is a sign of advancing age, or of the onset of Alzheimer's disease. Medical researchers strongly believe that environmental factors help trigger what is ultimately a genetic condition. [USA Weekend, Aug. 31- Sept. 2, 2001, p. 6] Mold contamination may be one of those environmental factors!
"Even if mold in your house doesn't cause you any medical problems, if it becomes established in the wood in your home, 'dry rot' may form. Dry rot can result in a homeowner's nightmare. When the mold dies, the wood dries and then shrinks, breaking up into irregular chunks. Cracks in the wood fiber then act like straws, siphoning up moisture and carrying it to undamaged portions of the wood. Left unchecked, this process keeps recurring, continually rotting more wood, and can cause severe structural damage to your home," warned Vicki Lankarge, on the website insure.com.
"Mold problems have become more prevalent because of increased use of cheaper building materials like plasterboard and plywood, which are more prone to growing mold when wet...Mold, as always, is spreading. But so is mold litigation, to the consternation of the insurance industry. Last week a state court in Austin, Texas, awarded Melinda Ballard and her family $32.1 million in a case involving allegedly extensive mold damage to their Dripping Springs, Texas, house. The jury ruled that Farmers Insurance Group had failed to properly address Ms. Ballard's original water-damage and mold claim and committed fraud in its handling of her claim," noted Christopher Oster, "Insurers Blanch At Proliferation of Mold Claims," Wall Street Journal, June 6, '01.
The black mold Stachybotrys found
in home, office and school environments has been linked to fatal pulmonary
The black mold Stachybotrys
found in home, office and school environments has been linked to fatal pulmonary
"About 38 percent of homes have mould and fungus growth due to elevated moisture." (The American Society of Home Inspectors) This problem is often worse in modern, tighter homes with little ventilation. Molds are fungi, simple microscopic plants. Mildew is a thin, black, or sometimes white, growth produced by mold. There are thousands species of molds. Outdoors, they live in the soil and help in the breakdown of organic matter. Molds grow indoors on virtually any substance when moisture is present.Molds can be usually detected by a musty odor. They produce mold spores (seeds), which waft in the air throughout the house, forming new colonies wherever they land. They grow on paper products, cardboard, ceiling tiles, wood products, paints, wallpaper, insulation materials, drywall, carpet, and fabric. Molds flourish in damp areas like crawl spaces, basements, bathrooms (especially shower stalls), air conditioners, humidifiers, clothing closets, refrigerator drip trays, house plants, garbage pails, mattresses, upholstered furniture, and often in new houses because of high moisture in the building materials.
Exposure to molds occurs when people inhale mold spores. Mold spores are so small that they evade the protective mechanisms of the nose and upper respiratory tract. Although thousands of molds exist, only a few dozen are significant allergens. They aggravate or cause allergies and asthma, particularly, in children. The incidence of allergies and asthma has doubled in the last decade, which has been linked to the increase in air-borne molds in modern energy-efficient homes. One of five Americans suffers from allergies. The other common effects of exposure to molds include nasal stuffiness, eye irritation, wheezing, flu like symptoms, chronic sinus infections, rashes, nosebleeds, fever, shortness of breath, headaches, dizziness, inability to concentrate, fatigue, and respiratory infections.
Some pathogenic molds effect the central nervous system or suppress the immune system. The growth of molds in your house should prevented to minimize the exposure to yourself and your family. You cannot eliminate all mold spores in the air, but, at the very least, you must reduce the exposure to allergens below the threshold at which your family experiences reactions.
Black MoldSome molds produce extremely potent toxins called mycotoxins. Large amounts of mycotoxins in air can cause serious illnesses like toxicosis (invasive infection). Some are carcinogenic and cause, for example, kidney cancer. Toxic "black molds" in homes and schools have caused public alarm. Some schools and many private homes had to be evacuated. Homeowners have lost their homes, because insurance companies normally do not cover this misfortune. There is actually a number of mold types that are black in color or produce black pigments. Such mold growths are common in houses, particularly in bathrooms and basements. The black molds known to produce mycotoxins include Stachybotrys and Memnoniella.
. Moisture Control is the Key to Mold Control
Concern about indoor exposure to mold has been increasing as the public becomes aware that exposure to mold can cause a variety of health effects and symptoms, including allergic reactions. This document presents guidelines for the remediation/cleanup of mold and moisture problems in schools and commercial buildings; these guidelines include measures designed to protect the health of building occupants and remediators. It has been designed primarily for building managers, custodians, and others who are responsible for commercial building and school maintenance. It should serve as a reference for potential mold and moisture remediators. Using this document, individuals with little or no experience with mold remediation should be able to make a reasonable judgment as to whether the situation can be handled in-house. It will help those in charge of maintenance to evaluate an in-house remediation plan or a remediation plan submitted by an outside contractor. Contractors and other professionals who respond to mold and moisture situations in commercial buildings and schools may also want to refer to these guidelines.
Many types of molds exist. All molds have the potential to cause health effects. Molds can produce allergens that can trigger allergic reactions or even asthma attacks in people allergic to mold. Others are known to produce potent toxins and/or irritants. Potential health concerns are an important reason to prevent mold growth and to remediate/clean up any existing indoor mold growth.
Since mold requires water to grow, it is important to prevent moisture problems in buildings. Moisture problems can have many causes, including uncontrolled humidity. Some moisture problems in buildings have been linked to changes in building construction practices during the 1970s, 80s, and 90s. Some of these changes have resulted in buildings that are tightly sealed, but may lack adequate ventilation, potentially leading to moisture buildup. Building materials, such as drywall, may not allow moisture to escape easily. Moisture problems may include roof leaks, landscaping or gutters that direct water into or under the building, and unvented combustion appliances. Delayed maintenance or insufficient maintenance are also associated with moisture problems in schools and large buildings. Moisture problems in portable classrooms and other temporary structures have frequently been associated with mold problems.
When mold growth occurs in buildings, adverse health problems may be reported by some building occupants, particularly those with allergies or respiratory problems. Remediators should avoid exposing themselves and others to mold-laden dusts as they conduct their cleanup activities. Caution should be used to prevent mold and mold spores from being dispersed throughout the air where they can be inhaled by building occupants.