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Mold and Their Health Effects. Edward J Peters, MD Austin Texas epeters@austinallergy.com. Fungi: Toxic Killers or Unavoidable Nuisances?. Court finds insurer at fault in mold case $32 million awarded…. The Austin American-Statesman, 6-2-2001. Austin American-Statesman 1-14-02. Fungi.
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Mold and Their Health Effects Edward J Peters, MD Austin Texas epeters@austinallergy.com
Fungi: Toxic Killers or Unavoidable Nuisances? Court finds insurer at fault in mold case $32 million awarded… The Austin American-Statesman, 6-2-2001
Fungi • Filamentous organisms that absorb food from the environment after external digestion. • Cell walls are made of a variety of materials that carry some antigenicity. • Most have a melanin pigment in the cell wall to protect from UV light. • Glucans in the cell wall are endotoxin-like and irritating and stimulate the immune system.
Definition: “Molds” • Common term for the multicellular fungi that grow as a mat of filaments. • Familiar fungi: yeasts, rusts, smuts, mushrooms, puffballs, and bracket fungi. • Exposure to fungi and their spores is unavoidable except in stringent air filtration and isolation situations (laminar flow units for bone marrow transplantation).
Are Fungi Pathogenic? • In healthy individuals, most fungi are not pathogenic. • Superficial infections of the feet, groin, nails and skin are the most common “infection”. • Limited number of fungi: Blastomyces, Coccidiodes, Cryptococcus, and Histoplasma can cause a severe illness in healthy individuals.
Allergenic Substances • All fungi produce some allergenic substances (enzymes) in the process of food digestion. • Mycotoxins and antibiotics can be released into the environment during growth. • 10% of the entire population and 40% of asthmatic patients are fungal-sensitive.
What do we know so far? • Lots of “molds” are black. • Exposure is unavoidable. • Most fungi have never caused disease in humans. • Lots of people but not all are allergic to fungi.
Indoor Levels of Fungi • In a home without water intrusion, the levels of airborne fungi will be 40-80% of the outdoor levels. • Outdoor concentrations vary widely by geographic area, season, atmospheric conditions (humidity, wind), and even time of the day. Verhoeff AP et al Allergy 1992; 47;83-91.
Sampling of Indoor Air: Problems • No uniform numeric standards for indoor sampling data. • No known dose-response relationship between a specific mold and any human health effects. • Exposure to fungi occurs indoors as well as outdoors, thus there is no way to ascribe a health effect or sensitivity to any specific exposure or time period.
Indoor Ambient Air Fungal Concentrations • In 820 residences without health complaints, indoor fungal counts averaged 1252 CFU/m3 and outdoor were 1524 CFU/m3. • In sawmills the airborne concentrations have been reported as high as 1.5 million CFU/m3 without health effects reported.
Respiratory Disease Caused by Fungi • Allergic asthma and allergic rhinitis are the commonest problems. • Allergic Fungal Diseases • ABPA: allergic bronchopulmonary aspergillosis • AFS: allergic fungal sinusitis • Invasive Fungal Diseases • Immunocompromised hosts (bone marrow transplant recipients/diabetes)
Hypersensitivity Pneumonitis • Results form the inhalation of significant quantities of fungal (or other) proteins. • Occupational exposures are the most common cause. Malt Worker’s Lung (Aspergillus) and Cheese Washer’s Lung (Penicillium) are due to fungal proteins. • Characterized by acute febrile illness and pneumonitis.
HP Case Report • 82-year-old female, hospitalized with acute RLL pneumonia, and symptoms cleared only to quickly return when she went home. • Repeat chest X-ray 2 weeks later R and L lung infiltrates. • Pulmonary function studies showed a FVC of 56% and FEV1 of 58%.
Hypersensitivity Pneumonitis Jacobs et al Ann Allergy Asthma Immunol 2002; 88:30
Did I lose you yet? • All homes (buildings) have some fungi especially if there is some water intrusion. • No standard way to sample airborne fungi. • Fungal diseases are either due to allergy or hypersensitivity in healthy people.
Sick Building Syndrome • Poorly defined set of symptoms (often sensory) attributed to occupancy of a building. • Investigations generally find no specific cause for the complaints. • “Toxic Mold” (Stachybotrys) and its mycotoxins have been blamed but no causal relationship has been found.
Mycotoxins • Metabolites from food digestion. • Aid the fungi compete for food by inhibiting growth of other organisms. • Low molecular weight and nonvolatile (not in air). • Health effects of mycotoxins comes from the animal or (rarely) human ingestion data, but not inhalation. • Penicillin and cyclosporine are examples of important “mycotoxins”.
Airborne Fungi in Buildings • Highest fungal levels (indoors and outdoors) from 1,717 buildings were found in the Southwest region. • Most common culturable airborne fungi were Cladosporium, Penicillium, and Aspergillus. • Stachybotrys chartarum was identified in the air of 6% of the buildings. Shelton et al Appl Environ Microbiol 2002;68:1743-53.
Deuteromycete: Stachybotrys “Fatal Fungus” • Spores are found worldwide on cellulose materials such as foam insulation, fiberboard, carpets, and even tobacco in cigarettes. • Mean concentration of 0.3 spores/m3 in 2.9% of homes in southern California. • In all cases, Stachybotrys is only a minor component of the mycoflora.
Deuteromycete: Stachybotrys “Fatal Fungus” • Slow-growing fungi that competes poorly with other rapidly growing fungi. • Recovered from air samples in 3-6% of surveys. • Saprophytic mold that grows on nonliving organic material (cellulose) in high humidity, and low nitrogen content. • Stachybotrys is recovered from water damaged building surfaces, but in low concentrations compared to Pencillium and Aspergillus species. Terr AI. Ann Allergy Asthma Immunol 2001;87:S57-63.
Human Diseases Caused by Stachybotrys • No case of a human systemic or local infection caused by any species of Stachybotrys. • One case of asthma improving in a 4 year old who was lived in a home that had Stachybotrys in water-damaged carpet, but not in air samples. • Possible toxicity to humans from ingestion of Stachybotrys exists as there are reports of horses dieing as the result of ingesting contaminated fodder in the 1930-1940’s in Russia.
Human Disease Caused by the Inhalation of “Killer Mold” • In 1986, five family members and their maid suffered from “a variety of maladies”. These authors claimed that there was a trichothecene mycotoxin in the air which caused the illnesses. • Two additional reports of work exposure to a variety of molds, including S. atra, in 1996 and 1998 resulted in various non-specific complaints and a single case of “interstitial lung disease” based on history. • Serum IgE and IgG to various fungi in all these cases were either negative or did not correlate with the exposures.
Acute Pulmonary Hemorrhage in Infants • Geographic cluster of 10 cases between the ages of 1 and 8 months in Cleveland, OH in 1993-1994. • Successfully treated in the hospital, but recurred in five of the infants shortly after returning home. • No other household members were effected. • Most lived in older, water damaged housing and had household exposure to Stachybotrys and other molds.
“Killer Mold” is not a killer? • Blamed for many problems (neurologic, memory, headaches) which have not been substantiated. • “Killer Mold” is only rarely found in the air and its mycotoxins are not breathable. • The term “Toxic Mold” is misleading as many molds are toxic if you ingest them.
Does Mold Cause Asthma? • 50% or more of homes of 4625 children reported dampness (molds, water damage, or water in basement). • Reported home dampness and mold is associated with “cough and wheezing”, but not clearly associated with asthma. • Pulmonary Function Tests (FVC or FEV1) were not effected by home dampness. Brunekreef et al Am Rev Respir Dis 1989; 140:1363
Household Mold Exposure in the First Year of Life • 880 infants at high risk for asthma (sibling with asthma) were followed for the first 12 months of life. • Cladosporium (62%) and Penicillium (41%) were the most commonest fungi found in these homes. • Highest Penicillium levels (>1,000 CFU/m3) were associated with wheeze and cough. Gent et al Environ Health Perspect 2002;110:A781-A786.
Effects of Indoor Fungi and Dust Mite Allergen Levels on Adults • Bronchial hyperreactivity (BHR) and history of wheezing were evaluated in 485 adults who participated in the ECRHS. • 77% of homes had levels of >10 μg/g dust mite allergen and 55% had airborne fungal counts >500 CFU/m3. • High levels of mold associated with BHR, but subsequent studies showed no relationship of levels of fungi (only “visible mold”) to Peak Flow. Dharmage et al Am J Repir Crit Care Med 2001;164:65-71. Dharmage et al Clin Exp Allergy 2002;32:714-20.
Dust Mite Exposure in US Beds • Dust mite allergen is a major risk factor for allergic sensitization and asthma. • Measurable dust mite allergen was found in bed dust of 84% of 831 homes with children. • 46% had levels associated with allergies, and 24% had levels seen in asthma (>10 μg/g). • Older single family homes, musty odor, and high bedroom humidity predicted higher levels. Arbes et al J Allery Clin Immunol 2003;111:408-14
Conclusion • Fungi are a major component of the biosphere and adapt well to varying conditions, such as water-damaged building materials. • Mycotoxins are produced by most fungi and Stachybotrys is not unique in this regard. • Stachybotrys remains a potential health risk, but human disease related to inhalation has not been established. • Furthermore, reports of subjective illnesses attributed to Stachybotrys are not compelling.
American Academy of Pediatrics Recommendations • Prompt cleaning of water damaged areas with dilute bleach. • Parents of infants with Idiopathic Pulmonary Hemorrhage should be questioned about mold, but “testing of the environment for specific molds is usually not necessary”. • Pediatricians should be aware that there is no method to test humans for “toxigenic molds”. Pediatrics 1998;101:712-4
Do we have to destroy everything because of mold? • No scientific studies support the need to destroy personal belongings or contents of rooms and buildings because they were in the environment. • Cleaning of the HVAC units with 0.25% Glutaraldehyde solution reduced fungi growth (CFU) for a least 8 weeks. Garrison et al Ann Allergy 1993;71:548-56.
Evaluation of Patient with “Toxic Mold” Symptoms • Many patients are CERTAIN that mold exposure has caused the problem. • Mold exposure “advocates” (physicians) have inappropriately promoted this idea. • A thorough evaluation often uncovers a pre-existing problem or underlying condition as the cause.
Evaluation and Work-up of “Mold Exposure” • Comprehensive medical history and complete physical examination. • Obtain and review all prior pertinent medical records which can sometimes be voluminous. • Laboratory evaluation may include a variety of tests depending on the type of complaint and exposure.
Laboratory Testing in “Mold Exposure” • CBC, chest x-ray, pulmonary function studies, and some testing for common allergens (skin testing or serologic testing) are usually necessary and indicated. • Nasal smears, CT scan of the sinuses, and general chemistry screens are often obtained. • Methacholine challenge for hyperreactivity can be very helpful when spirometry is normal.
Role of Consultants in the Evaluation of “Mold Exposure” • Indoor air quality assessment by a Certified Industrial Hygienist may be necessary especially in medical-legal evaluations. • Rely on cultures of airborne fungi (CFU/m3) and do not rely on spore counts or bulk specimens if you are trying to evaluate the health risk.