The ongoing research, litigation and debate concerning the health effects of mold exposure continue to occupy the laboratories, courtrooms and the press. The novelty of a new alarm in the trades is always intriguing and the controversy will probably not end soon. Not every black stain bleeding through the wall is necessarily a mold colony or even hazardous.
These days, however, just the slightest hint of mold can cause a real estate deal to fold or a construction job to grind to an expensive halt. But talk to someone who has actually been diagnosed with a mold-related respiratory disease and it soon becomes clear that, for some individuals, molds can change your life forever.
Symptoms
While fungus infections and related diseases may not disable a great number of American construction workers, many cases undoubtedly go unreported or are misdiagnosed as another upper respiratory tract infection. A recent Harvard Medical study concluded that in 10,000 homes, mold exposure was associated with a 50 to 100 percent increase in respiratory distress symptoms. Other studies suggest that molds contribute significantly to a 300-percent or more increase in asthma diagnoses in the past 20 years.Many people allergic to molds, mildew and fungus, exhibit a wide range of irritating, acute symptoms, such as asthma, skin rashes, fatigue, irritability and congestion. More severe symptoms may include coughing, nausea, headaches, arthritic aches and joint pain. The initial exposure symptoms are often flu-like and not until the diseases become advanced is a diagnosis of a mold-induced disease even made. However mycotoxins (poisonous mold byproducts) are very destructive and often produce chronic symptoms such as impaired breathing, memory loss, hearing, speech and eyesight degradation, loss of balance and even epileptic-like seizures and brain damage.
Recently, there have been several mold-infested "sick buildings" in my own rural upstate New York community that were discovered during either renovation, demolition or re-roofing projects. Several of the local workers involved were infected, diagnosed and are now recovering with some very serious and long-term health effects of aspergilliosis. This respiratory disease is caused by exposure to the black mold in the genus aspergillus.
I know of several other cases that may have been misdiagnosed or gone unreported, as the symptomology can be misleading. While many species of mold are tropical and subtropical in origin, many others are adaptable to our northern climates as well, especially when an insulated envelope is constructed and heated during the cold months. Warm, moist inside air traveling against a cold surface condenses into liquid (usually within the insulation envelope) and is trapped by various building materials preventing evaporation. Most of us do not observe this trapped water vapor as it condenses, freezes and thaws season after season. It is most often discovered by the contractor during a renovation or repair project.
The tighter we envelope our homes and workplaces, the more difficult it becomes to control moisture migration. Molds are colonial by nature and must expand their limits to survive. Molds can grow nowhere unless a dependable source of moisture is available.
Aspergillus (black mold)
While most molds and fungi are benign, slightly irritating or even beneficial (penicillin and blue cheese), some are very toxic to humans. The class of pathogenic molds that present the greatest hazard to workers involved with additions and wall/ceiling penetrations, interior renovations, and especially demolition are classified as "black molds." This group includes stachybotrys chartarum, cladosporium, aspergillus fumigtus (and more than 50 other species), fusarium, trichoderma, penicillium and memnoniella.Of this group, the stachbotrys, penicillium and aspergillus are the most common in residential, commercial and even industrial structures. Most large municipality and state departments of health have researched and developed public health protocols to address these indoor environmental contaminants, including testing and assessment techniques, remediation procedures and hazard communication policies. There are also federal agencies that are concerned with the health effects of molds, such as OSHA, NIOSH, CDC and EPA. Most large universities also support widespread mold investigation and research that can be accessed by way of their Web sites.
While some species may produce organ-specific physical reactions (eyes, ears, nose, throat and lungs), it is the fungal mycotoxins and volatile organic compounds that are produced as metabolites, which pose the greatest harm to the exposed worker. The fungus (or any fragment of mycelia) spore or metabolite that is inhaled may prove invasive and quite infectious.
It is commonly assumed that airborne particles less than 50 microns in diameter, which are inhaled may bypass the cilia in our trachea, our mucous membranes in our nose and throat and travel down the brachial tubes to our lung's air sacs (aveoli). Here, the transfer of oxygen and carbon dioxide occurs through surrounding capillary cell walls. The diameter of most mold spores is fewer than four microns (250,000 on a pin-head), which makes them very aggressive.
These spores are also very opportunistic, as the lung is also a dark, warm, moist and confined space. Molds may colonize from the brachial tree to the aveoli, producing debilitating plugs consisting of mold hyphae and fibrin. This typically causes a high chest pain and a non-productive cough, with blood-tinged sputum, which often mimics tuberculosis. As with the inhalation of asbestos fibers or silica particles, the body reacts to molds by sending macrophages in the bloodstream to ingest and destroy these invaders.
When ingested by these cells, the mycotoxins destroy the marcophage and lung scarring becomes a common defense. This eventually reduces the average 32 square feet of lung tissue capable of transmitting oxygen to the blood and CO2 to the lungs. Less oxygen to the cells causes brain and tissue damage. Acidic carbon dioxide builds up in the blood and tissues leading to fatigue and potential collapse.
Diagnosis and treatment
A large volume inhalation of mold spores may cause a disorder known as organic dust toxic syndrome or "farmer's lung." Acute symptoms may often present within four to eight hours after exposure and include fatigue, chills, shortness of breath, painful tight chest, headache, increasing weakness, fever and sweating, suppressed appetite, and thick phlegm and chronic coughing. Sometimes, repeated low-volume exposures to these spores may cause hypersensitivity pneumonitis, which compromises the immune system and may cause permanent lung damage. Pulmonary hemorrhages in the developing lungs of infants has also been diagnosed from mold spores. Aspergiliosis is a disease, which left untreated, may in some individuals even result in cerebral hemorrhage and fatality. The disease may be segregated into three separate diagnoses:Disseminated Aspergillosis: This acute infection produces a range of effects, including septicemia, thrombosis and infarction of the lungs, heart, kidneys and brain. It is diagnosed by chest X-rays, which reveal crescent shaped radiodlucency surrounding a circular mass (mycelium). This debilitating disease may also cause other infections, including pneumonia, endocarditis (heart valve), dyspnea (gag response), lung abscesses and brain abscess.
Allergic Aspergillosis: This is a hypersensitive asthmatic reaction to the aspergillus antigens in the blood system. It is typically diagnosed by sputum examination and laboratory culture (two weeks). This disease may lead to opportunistic infections, including sinusitis and ear infections. It is often accompanied with pleural pain and fever.
Aspergillosis Endopthalmitis: This infection of either the anterior or posterior chambers of the eye, which may cause temporary or permanent blindness if left untreated. Associated infections often include corneal keratitis.
As aspergillosis is non-transmittable between individuals, it does not require patient isolation or quarantine. Disseminated aspergillus is typically treated by an aggressive antifungal course of intravenous Amphotericin B for two to three weeks, local surgical excision of lesions and chest physiotherapy (coughing) to improve pulmonary function. There are hospitals and treatment centers (mostly located along populated river valleys) that specifically diagnose and treat mold-related diseases and disorders.
It has been noted by specialists that psychological depression is often common with patients with mold-induced diseases as the treatment often includes long and intense periods of hospitalization and rehabilitation. The debilitating effects of respiratory distress and intoxification often extend beyond the initial treatment period. Many mold-induced disease victims are even considered at high-risk for re-infection at much lower spore concentrations.
Regular, semi-annual cardio-pulmonary check-ups are strongly recommended for mold victims for the first few years after treatment. In some states, this is often legally considered an extenuating health-related circumstance, keeping many workers compensation files open for the lifetime of the victim.
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Mold testing and analysis
As a construction contractor, you are not expected to obtain a graduate degree in microbiology or mycology in order to protect your employees or your business. However, your written contract should contain a "non-disclosure" clause that is adequately phrased to reduce your liability and release your obligations to perform your contract when undisclosed conditions involving hazardous materials (including biohazards) are discovered or suspected.You may even require the property owner or prime contractor to perform definitive environmental testing and analysis prior and post to your commencing work when any hazmat is suspected. At that point you may even choose to abate the mold hazard yourself in the performance of your roofing or demolition project. In the state of New York where I live, there is no state-certification program for mold abatement contractors. While the National Institute of Safety and Health and the Center for Disease Control have a detailed protocol and policy for mold remediation, most state and local governments have remained uncommitted to legislate in this area.
However, if another contractor or owner is undertaking the removal of black mold infested materials from your project, before you start you should have copies of the lab tests taken prior and post abatement. In most cases, if the gross contamination of mold is observed (either a musty, anaerobic smell, dark black stain on building materials, etc.) and a worker is showing any of the initial exposure symptoms, you may proceed as if there is a hazardous mold exposure.
However, due to the cost and delay factors of abatement, the owner or prime contractor may argue that these symptoms and observations do not conclusively prove the presence of harmful molds. Therefore, testing may be required. Testing may be either performed by bulk sampling or air test procedures and follow these minimal, non-inclusive parameters:
• Testing may be practiced when mold is suspected (smelled) but not observed.
• Testing (air or grab sampling) should not be practiced in a manner that agitates the mold or unnecessarily exposes unprotected workers. Ventilation shut off and windows closed for still-air conditions.
• Tests may either be taken by individual test kits, which are mailed back to a lab for testing or analysis, or else performed by a certified industrial hygienist for a reputable environmental testing agency. In any case, you should protect your workers and your firm, by thorough documentation, photographs and daily work logs sufficiently detailed to enable you to adequately reconstruct the work shift three years later.
• Air monitoring may not be necessary, except in the diagnosis of either aspergilliosis or stachybotriosis in a worker.
• Air tests should be concurrently taken at any natural air inlet into the affected space to eliminate the possibility of cross contamination.
Personnel performing the tests shall be:
a) Medically examined to ensure capable to enter area.
b) Thoroughly trained and evaluated in biohazard awareness and hazmat decontamination procedures.
c) Fit-tested for and supplied with the appropriate personal protective equipment for the hazard level assumed.
Analysis of test results must be made by either a professional accredited by the American Industrial Hygiene Association or by a lab certified by the Environmental Microbiology Laboratory Accreditation Program.
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Remediation and disposal
If you choose to undertake mold remediation as part of a renovation/demolition project, there are definitive actions that should be taken. Special emphasis should be placed on comprehensive and hands-on training of abatement personnel before exposing them to the health hazards. Often, a simple exposure can produce medical conditions that affect their lives for years to come. They should also have access to the best professional equipment available, including fit-tested respirators, level B protective clothing, and task-specific tools such as moisture meter, remote cavity biohazard samplers, fiber optic scopes, cassettes for sampling airborne aerosols, and decontamination supplies, just to name a few.A written, site-specific mold abatement plan should be developed by the employer and every member of the abatement team should be trained in its specific procedures, as well as their own assigned tasks. Removal of mold-contaminated materials (such as insulation, framing, plaster and gypsum board) and post-demo handling methods, should be conducted using a pre-determined set of safe work practices including engineering controls (encapsulation, barriers, ventilation), administrative controls (training, controlled access zones, shared exposures, decontamination, vapor proof waste containers) and finally personal protective equipment (level B clothing, respirators, supplied air).The species of the mold and the size (volume) of the abatement area are crucial to determining an adequate abatement plan. The reaction time is also crucial with molds, due to their rapid and aggressive colonization patterns. The amount of exposure time and extent of disturbance is critical. As with any poison, dosage is calculated by multiplying the concentration (particles per cubic centimeter) times the length of exposure. The ease with which we may be exposed by several inhalations, emphasizes the need for writing and practicing an efficient mold abatement plan.
Water leaks and accumulation should always be stopped immediately as moisture is essential to growth and the production of spores. Relative humidity should be tested and maintained below 60 percent (40 percent is ideal) to inhibit mold growth. Always remember the goal of remediation is to remove or clean contaminated materials by methods that prevent the emission of fungi particles and spores that may contaminate clean areas or infect workers.
Whenever gross fungal growth is observed, or even suspected, by anyone on the job site, the property owner should be immediately notified. The owner should then proceed according to hazard communication methods to notify all affected employers on the work site. These employers, such as an interior finish contractor, should likewise notify and evaluate his workers. If remediation is required, then all affected employees should be included in pre-abatement meetings with a disclosure of all the procedures in the mold abatement plan.
A simple diagnostic mold culture test kit can achieve certified laboratory analysis and species identification for approximately $30 in five to seven days. A more expensive airborne particulate test will indicate the sample concentration of mold (in spores/cc). This is a particularly important post-mitigation test to determine the level of success of the abatement. Knowledge and preparation is the best health defense for the contractor. Medical records and symptomatic post-exposure records should be diligently recorded. Any employees with persistent health problems related to bioaerosols should be referred to a professional medical practitioner, trained in mycological diagnosis and treatment. Thorough hazard communication is the essential key to a biohazard, such as black mold.
Widespread mold contamination during construction demolition or inspection can prove to be an aggressive and opportunistic source of infection from just a brief exposure. For some individuals it appears a single exposure to concentrated black mold or fungus colonies growing in confined spaces behind the wall or ceiling during demolition may be dangerous. Training and experience in mold awareness and identification, as well as the ability to take prompt corrective measures, such as evacuating the affected area, are the prerequisites for a competent person on the job.
Make sure your supervisors and job foremen are aware of the health hazards of molds and fungi on their projects and are adequately trained to identify potential conditions for mold growth. The odds of mold contamination on most jobs are minimal but it only takes a single, deep breath of contaminated air for some individuals to become infected. So, take the time to become trained in mold hazards and the appropriate emergency action plan. Endeavor to keep the lines of communication open from each worker, through site supervision, straight to your office and the effects of black mold health hazards will be minimized.
Sidebar
The basic recommended levels of mold and fungus remediation
LEVEL I: Small isolated areas (10 square feet or less) such as ceiling tiles, small area of wall gypsum board.• Abatement workers may be appropriately Hazard-Awareness-trained maintenance personnel.
• Provide NIOSH N95 respirators, gloves and protective clothing in accordance to OSHA standards.
• Evacuating non-essential personnel (with medical evaluations).
• Dust suppression procedures (misting) by 100-percent containment is not required.
• Contaminated materials that cannot be cleaned should be removed in double sealed plastic bags. Check state requirements for disposal of moldy materials.
• Visibly free from contamination/debris.
LEVEL II: Mid-sized isolated areas (10 to 30 square feet), such as several pieces of gypsum wallboard.
• Abatement workers may be appropriately hazard-awareness trained maintenance personnel.
• Provide NIOSH N95 respirators, gloves and protective clothing in accordance to OSHA standards.
• Evacuating non-essential personnel (with medical evaluations).
• Cover work area with plastic sheet with taped seams to contain dust.
• Dust suppression procedures (misting) is recommended.
• Contaminated materials that cannot be cleaned should be removed in double sealed plastic bags. Check state requirements for disposal of moldy materials.
• Areas used by workers for egress should be HEPA vacuumed and cleaned with antimicrobial detergent, and left dry and visibly free from contamination/debris.
LEVEL III: Large isolated area (30 to 100 square feet) such as several wall board panels.
• An experienced microbial-certified safety and health professional to be consulted prior to remediation to develop abatement plan.
• Abatement workers may be appropriately Hazard-Awareness-trained maintenance personnel.
• Provide NIOSH N95 respirators, gloves and protective clothing in accordance with OSHA standards.
• Evacuating non-essential personnel (with medical evaluations).
• Cover work area with plastic sheet with taped seams to contain dust and seal adjacent HVAC systems.
• Dust suppression procedures (misting) is recommended.
• Contaminated materials that cannot be cleaned should be removed in double sealed plastic bags. Check state requirements for disposal of moldy materials.
• Work area used by workers for egress should be HEPA vacuumed and work area cleaned with antimicrobial detergent and left dry and visibly free from contamination/debris.
If abatement method is expected to produce a lot of dust, such as by abrasive cleaning or demolition or the fungi is very visible in heavy blanket or pocket concentrations, then Level IV remediation procedures should be followed.
LEVEL IV: Extensive contamination (more than 100 square feet contiguous area) or any exposure that resulted in a positive medical diagnosis of a mold-related disease of condition.
• An experienced microbial-certified safety and health professional to be consulted prior to remediation to develop abatement plan.
• Pre-entry and continuous air monitoring recommended.
• Abatement workers should obtain advanced mold hazard and decontamination training for experienced, professional abatement personnel.
• Provide NIOSH N100 respirators, disposable gloves and protective clothing that covers head, feet and hands in accordance to OSHA standards.
• Evacuating non-essential personnel (with medical evaluations).
• Completely isolate work area with plastic sheet with taped seams to contain dust and seal adjacent HVAC systems.
• Provide NIOSH approved exhaust fan with HEPA filter to generate negative pressure to sealed work area.
• Design and provide adequate airlocks and decontamination room.
• Contaminated materials that cannot be cleaned should be removed in double sealed plastic bags. Clean outside of bags in decon chamber with HEPA vacuum (99 percent efficiency) prior to transport to uncontaminated area of building. Check state requirements for disposal of moldy materials.
• Contained work area used by workers for egress should be HEPA vacuumed and work area cleaned with antimicrobial detergent and left dry and visibly free from contamination/debris.
Post-abatement air monitoring prior to reoccupation is also recommended.