3 May 1999
Source: http://www.ci.nyc.ny.us/html/doh/html/epi/moldrpt1.html

See also ENR cover story of May 3, 1999, "Buildings That Stink": http://www.enr.com/new/coverstry.asp

Based on a panel discussion
May 7, 1993
District Council 37 AFSCME
125 Barclay Place
New York, New York 10007

Sponsored by:
New York City Department of Health
New York City Human Resources Administration
Mount Sinai-Irving J. Selikoff
Occupational Health Clinical Center

Introduction

I. Health Issues

II. Environmental Assessment

III. Remediation

[IV and V apparently not used]

VI. Hazard Communication

Conclusion

Executive Summary

On May 7, 1993, the New York City Department of Health (DOH), the New York City Human Resources Administration (HRA), and the Mt. Sinai Occupational Health Clinic convened an expert panel on "Stachybotrys atra (SA) in Indoor Environments". The purpose of the panel was to develop policies for medical and environmental evaluation and intervention to address SA contamination. This document summarizes the panel's recommendations.

Contamination of indoor air by SA is thought to be rare. [See "Facts About Mold," below.] SA is generally found on materials with a high cellulose content (such as fiberboard, gypsum board, dust and lint) that become chronically moist or water damaged due to excessive humidity, water leaks, condensation, infiltration, or flooding. Such conditions are often accompanied by multiple mold contaminants and other air quality problems. Areas growing SA or other microbial contaminants must be repaired as rapidly as possible in order to ensure a healthy environment. Specific methods of assessing and remediating SA contamination must be based on the extent of visible contamination and underlying damage. The simplest and most expedient remediation that properly and safely removes SA contamination should be used. Repair of the defects that led to water accumulation should be done as quickly as possible. Contamination of a discrete area -- which is likely to characterize the majority of areas where SA is found -- can be assessed and remediated by building maintenance personnel, using the protocols described in this document. Widespread contamination, particularly if heating, ventilating, air conditioning (HVAC) systems or large occupied spaces are involved, require assessment and remediation by personnel with training and experience handling microbial contaminated material. In order to prevent contamination from recurring, underlying defects causing moisture buildup and water damage must be addressed. Effective communication with building occupants is an essential component of all remedial efforts.

SA in buildings may cause or exacerbate allergic type symptoms (such as wheezing, chest tightness, shortness of breath), especially in persons who have a history of hypersensitivity diseases (such as asthma, hypersensitivity pneumonitis, and severe sinusitis). The attack rate (percentage of occupants who develop these reactions) is generally low. Individuals with persistent health problems should be referred for medical evaluation by a physician trained in occupational or environmental medicine and knowledgeable about exposures to fungal contaminants. Decisions about removing individuals from an affected area must be based on the results of such medical evaluation, and be made on a case by case basis. Except in cases of widespread SA contamination, building-wide evacuation is not indicated.

In summary, prompt removal of contaminated material and infrastructural repair is the primary response to SA contamination in buildings. Emphasis should be placed on preventing contamination through proper building and HVAC system maintenance and prompt repair of water damage.

Introduction

Stachybotrys atra (SA) is a greenish-black fungus that can grow on materials with a high cellulose and low nitrogen content (such as fiberboard, gypsum board, dust and lint) that become moist or water-damaged, due to excessive humidity, chronic leaks, condensation, infiltration or flooding. The prevalence of SA contamination in indoor environments is unknown because buildings are not routinely tested for its presence. Recently, several cases of SA contamination in NYC buildings were reported to the New York City Department of Health (DOH).

Currently there are no Federal, State or City regulations or guidelines for evaluating potential health effects of SA contamination and remediation. To address this regulatory gap, DOH, HRA, and the Mount Sinai Occupational Health Clinic convened an expert panel on "Stachybotrys Atra (SA) in indoor environments" on May 7, 1993. The purpose of the panel was to develop policies for medical and environmental evaluation and intervention to address SA contamination. The panel consisted of seven authorities on the subject: Donald Ahearn and Sidney Crow from Georgia State University, Bruce Jarvis from the University of Maryland, William Sorenson from the National Institute for Occupational Safety and Health (NIOSH) (Morgantown, WV), Philip Morey from Clayton Environmental Consultants, Robert Vogt from the Centers for Disease Control and Prevention (CDC) (Atlanta) and David Miller from Agriculture Canada (Ottawa).

This document, summarizing the recommendations for evaluating and remediating microbial contamination, is based on the May 7,1993 panel discussion. It was developed in cooperation with the Mt. Sinai Occupational Health Clinic and New York City Department of Health. The document contains a discussion of potential health effects and necessary medical evaluation; an outline of the criteria utilized to trigger an environmental assessment; protocols for initial inspections, sampling, environmental monitoring and the evaluation of data; remediation and cleanup procedures and a discussion of risk communication strategy. The criteria and protocols are divided into four sections: I. Health Issues; II. Environmental assessment; III. Remediation; and IV. Hazard Communication.

I. Health Issues:

A. Health Effects

SA can produce several toxic chemicals called trichothecene mycotoxins. These mycotoxins are known to be toxic to both humans and farm animals exposed to significant quantities. Initially the toxic effects of the mold were seen in farm animals that had eaten contaminated hay or grain. Farm workers also experienced health effects (dermatitis, blood and immune system disorders) from handling contaminated material. A recent evaluation of several tricothecenes by the International Agency for Research on Cancer (IARC) found no evidence that they cause cancer.

There have been only a few documented cases of health problems from indoor exposure to SA. In general, the intensity of exposure and health effects from SA in the indoor environment are much less severe than those which were experienced by farm animals and workers.

If SA spores are released into the air, there is a potential for allergic, respiratory or immunologic symptoms to develop or become exacerbated. These conditions include: asthma, hypersensitivity pneumonitis, allergic rhinitis, dermatitis, sinusitis and conjunctivitis. It is thought that these diseases are mediated by an immune response to SA (or other environmental agents). Many of the related symptoms are non-specific, but debilitating, such as discomfort, inability to concentrate and fatigue. Presently, it is not known whether long-term indoor exposure to airborne SA increases the risk of certain chronic respiratory diseases. In one reported case of indoor exposure, residents experienced cold and flu symptoms, diarrhea, headaches, fatigue, rashes and other symptoms. These symptoms disappeared after all of the contaminated duct work, insulation, and ceiling material was replaced.

B. Association between SA in buildings and health effects

Health risk cannot be predicted based simply on the presence of SA in building materials as indicated by bulk sampling results. In order for humans to be exposed indoors, spores must be released into the air and inhaled. Also, it appears that the symptoms listed above are not likely to develop in all persons exposed at levels likely to be found in buildings. The attack rate (percentage of persons who develop symptoms) is generally low. At the present time, "safe" (or "unsafe") exposure levels have not been established.

C. Medical Evaluation

Individuals with persistent health problems should be referred to practitioners trained in occupational/environmental medicine or related specialties and knowledgeable about these types of exposures. Some physicians are beginning to conduct tests for biological markers (eg. in blood samples) of SA exposure. However, such tests are not readily available or interpretable and should not be routinely used in a public health or primary care setting. For example, a negative test result does not conclusively "prove" that there has been no exposure to SA.

D. Medical Removal

Persons with asthma, hypersensitivity pneumonitis, severe allergies, sinusitis, immune suppression, or other chronic inflammatory lung diseases appear to be at greater risk for developing health problems associated with SA (as well as other fungi which are commonly found in water-damaged areas). Such persons may need to be removed from the affected area until remediation and clearance testing, if required, are completed. Decisions about medical removal must be based on the results of a clinical assessment by a trained occupational/environmental health practitioner. Evacuation of an entire area or facility is generally not warranted, except in cases of widespread contamination, particularly involving a ventilation system.

II. Environmental Assessment

A. Criteria for Initial Inspection

Reports about potential SA contamination in buildings should be followed up to ascertain whether a site inspection is warranted. The criteria for conducting an initial inspection include:

1. presence of visible mold;

2. evidence of water damage;

3. symptoms which are consistent with an allergic or toxic response to SA (eg. respiratory illness, rashes and chronic fatigue) and are severe enough as judged by medical documentation to result in lost work days.

B. Inspection Procedures

If visible mold, water damage, and occupants exhibiting related symptoms serious enough to result in lost work days are present, a site inspection should be conducted. The results of all site inspections should be compiled into a written report, and made available to the building owner, employer and employee representatives in the affected areas. Such an inspection should be conducted according to the following protocol:

1. Visual Inspection.

Visual inspection is the most important initial step in identifying a possible contamination problem. Visual identification of black mold in chronically-wet areas is considered to be a possible indicator of SA. Ceiling tiles, gypsum wall board, cardboard, paper, and other cellulosic surfaces should be given careful attention during visual inspection. The extent of any water damage and mold growth should be evaluated as this will be important in determining remedial strategies. Ventilation systems should also be visually checked, particularly for damp filters.

2. Bulk Sampling

a. If only a limited area is affected (i.e. all or part of an area that is approximately 30 square feet or less), the water damage is the result of a known occurrence, and no occupants are experiencing symptoms, then bulk (or other sampling) is not required. Remediation (as described under Remediation, Section A) should proceed without further evaluation, under the assumption that SA or (other fungal contaminants) are present.

b. Bulk samples should only be used to document the presence and extent of SA if extensive areas are affected, for example if visible mold occurs on areas larger than one wall board panel and water damage is a chronic problem, or if occupants are experiencing symptoms which may be related to SA exposure.

c. When bulk sampling is required, designated personnel should collect bulk samples from appropriate areas (eg. damp, moldy cellulose-derived material) by scraping surface materials into a clean ziploc plastic bag or by stripping the suspect surface with vinyl acetate tape.

3. Air Monitoring

a. Air sampling for SA should not be part of a routine assessment. This is because air sampling methods for SA are prone to false negative results and therefore cannot be used to rule out contamination. In addition, when the size of the affected area is small or moderate, decisions about appropriate remediation strategies can be made on the basis of visual inspection and bulk sampling.

b. Air monitoring may be required if there is evidence from visual inspection or bulk sampling that ventilation systems may be contaminated. The purpose of such air monitoring is to assess the extent of contamination throughout a building.

c. If air monitoring is conducted, personnel conducting the sampling must be trained in proper air sampling methods for microbial contaminants.

C. Evaluation of Environmental Data

1. Analysis

a. Documented quality control in the laboratories used for analysis of the bulk and air samples is necessary. SA is easily missed if other species are present and microscopic identification of the spores requires considerable expertise. These services are not routinely available from commercial laboratories. The laboratory director should be familiar with the literature concerning SA. A list of approved laboratories is available from the New York State Department of Health (518) 474-7413.

b. Samples should also be analyzed for the presence of other common indoor microbial contaminants.

c. Both indoor and outdoor air samples from nearby areas without signs of contamination should be collected and compared.

2. Evaluation criteria

a. Bulk sampling: Sampling results in excess of 1 colony forming unit per gram should be considered positive. Surfaces that were sampled and found to be contaminated with SA need to be remediated, as described in Section III.

b. Air monitoring:

1. Concentrations of mold in indoor air which exceed concentrations in outdoor air should be considered positive. Remediation of surfaces and general cleaning is required, as described in Section III.

2. Airborne concentrations of 103-104 cfu/m3 or greater require immediate evacuation of all occupants.

III. Remediation

Different levels of containment are necessary depending on the extent of the contamination problem. In all situations, the underlying cause of water accumulation must be rectified or the problem will recur. There must be a mechanism in place for ensuring an immediate response to these problems. Clean up should be conducted when the affected area is unoccupied. In all remediations, a routine follow-up inspection at 6-12 months or sooner if visible mold contamination or water damage recurs should be conducted. Emphasis should be on ensuring proper repair of the building infrastructure, so that water damage and moisture buildup do not recur.

Four different levels of abatement, as described below, are identified, based on the extent of SA contamination.

A. Level I: Small Isolated Areas (2 sq. ft or less)

1. Example: ceiling tiles

2. Cleanup can be conducted by regular building maintenance staff. Such persons must receive training from a qualified individual on proper clean up methods, protection, and potential health hazards, and should be free from asthma, allergy and immune suppressive disorders. Gloves and a half face respirator should be worn. A full respiratory protection program, in accordance with 29 CFR 1910.134 is required.

3. Contaminated absorbent material should be removed in a sealed plastic bag

4. Surrounding areas should be cleaned with household bleach.

5. Special containment or evacuation measures are not necessary.

B. Level II: Larger Isolated Areas (2 - approximately 30 sq. feet)

1. Example: individual dry wall panels.

2. Cleanup can be conducted by regular building maintenance staff. Such persons must receive training from a qualified individual on proper clean up methods, protection, and potential health hazards, and should be free from asthma, allergy and immune suppressive disorders. Gloves and a half face respirator should be worn. A full respiratory protection program, in accordance with 29 CFR 1910.134 is required.

3. Surrounding material should be covered with plastic sheets and tape before removal.

4. Contaminated absorbent material should be removed in a sealed plastic bag

5. Surrounding areas should be cleaned with household bleach.

C. Level III:Large Scale Remediations(1) (more than 30 square feet)

1. Example: More than one wall board panel in an area which cannot be isolated from personnel.

2. Personnel trained in the handling of hazardous materials are necessary.

3. Containment of the affected area is required

1. Complete isolation of work area from occupied spaces using plastic sheeting sealed with duct tape (including openings, fixtures and HVAC components) is required.
2. A high efficiency particulate air (HEPA) exhausted negative air unit is required.
3. Airlocks and decontamination room are needed for exit from work area.

4. Contaminated material should be removed in double-sealed plastic bags.

5. The work area must be HEPA vacuumed prior to the removal of isolation barriers.

6. Clean up workers should wear:

a. Full-face respirators with HEPA cartridges or powered air purifying respirators

b. Disposable protective clothing, head gear, foot covering, gloves

7. Air monitoring:

a. should be conducted during remediation to determine if spores are escaping during remediation and prior to removal of isolation barriers to assess the efficacy of the remediation.

b. should be conducted after large scale remediation, to determine its effectiveness and whether and area is safe for symptomatic persons to reoccupy. If post-remediation air samples indicate the presence of SA, even in minor amounts, further investigation of possible sources is required.

D. Level IV: Remediation of HVAC Systems

1. Personnel trained in the handling of hazardous materials are required for remediation of HVAC systems
   
2. Containment of the affected area is required

a. Complete isolation of work area from occupied spaces using plastic sheeting sealed with duct tape (including openings, fixtures and other HVAC components) is required.

b. A high efficiency particulate air (HEPA) exhausted negative air unit is required.

c. Airlocks and decontamination room are needed for exit from work area.

3. Contaminated material should be removed in double-sealed plastic bags.

4. The work area must be HEPA vacuumed prior to the removal of isolation barriers.

5. Clean up workers should wear:

a. Full-face respirators with HEPA cartridges or powered air purifying respirators

b. Disposable protective clothing, head gear, foot covering, gloves

6. If SA is present in settled dust removal with a HEPA equipped vacuum and subsequent damp wiping is recommended

7. Air monitoring:

a. should be conducted during remediation to determine if spores are escaping during remediation and prior to removal of isolation barriers to assess the efficacy of the remediation.

b. should be conducted after large scale remediation, to determine its effectiveness and whether an area is safe for symptomatic persons to reoccupy.

If post-remediation air samples indicate the presence of SA, even in minor amounts, further investigation of possible sources is required.

8. Growth supporting material should be removed from ducts with a HEPA vacuum, where practical, if not removal of the affected component of the HVAC system is required

9. Contaminated material should be disinfected prior to removal. Decisions concerning the type of disinfection should be made by a qualified individual, based on the extent of the growth supporting material. Decisions as to disinfection must be based on the extent of the growth substrate in the ducts. There are numerous "biocides" such as quaternary ammonium compounds (e.g. dimethylbenzyl ammonium chloride) that are employed routinely for disinfection and cleaning surfaces, particularly in hospitals and laboratories. Some of these biocides are recommended by manufacturers for use with cooling coils and condensation pans. In fact, the biocides are essential for maintaining the system. Household bleach is often recommended and can be used to clean coils. Chlorine dioxide or ozone are used for disinfecting inside of ducts.

Potentially toxic substances such as chlorine dioxide or ozone that are currently used for disinfecting duct work should not be used when the building is inhabited. Also, sufficient time should be allowed for the disinfectant to dissipate. These substances, however do have a short half life. As to whether they would be efficacious or not would depend upon the extent of the contamination and circumstances of application. As a safety factor it may be advisable to disinfect molded material within a duct system prior to cleaning.

10. The causes of SA accumulation and/or growth must be identified and corrective action taken.

[IV and V apparently not used here.]

VI. Hazard Communication

When SA is found, occupants in the affected area(s) should be notified of its presence by the building owner and the employer. Notification should include the a description of the remedial measures to be taken and a timetable for completion. Group meetings held before and after remediation with full disclosure of plans and results can be an effective communication mechanism. Some individuals may require separate counseling. They should be encouraged to seek medical advice from a qualified occupational/environmental health practitioner if they are concerned about continuing health problems. Individuals seeking medical attention should be provided with a copy of all inspection results and interpretation to give to their medical practitioners.

Conclusion

In summary, prompt removal of contaminated material and infrastructural repair must be the primary response to SA contamination in buildings. Emphasis should be placed on preventing contamination through proper building maintenance and prompt repair of water damaged areas.

Chronic exposure to airborne SA poses a risk of debilitating health effects caused by irritative and allergic reactions. This risk is compounded by exposure to additional molds and other pollutants usually found in buildings contaminated by SA. Laboratory tests for immune markers associated with SA exposure are not helpful at this time. Research should be pursued to refine such tests and characterize them more fully.

The simplest and most expedient remediation that properly and safely removes SA from buildings should be used. This includes prompt removal, cleaning of contaminated sites and repair of the defects that led to water accumulation. Widespread contamination poses much larger problems that must be addressed on a case-by-case basis in accordance with published guidelines for remediation. Effective communication with building occupants is an essential component of all remedial efforts. Individuals with persistent health problems should be referred to physicians competent in evaluating health effects of microbial exposures.

(1) Morey PR. Microbial contamination in buildings: precautions during remediation activities. 1992

December 1998

New York City Department of Health
Environmental and Occupational Disease Prevention

What is mold and where is it found?
Molds (fungi) are present EVERYWHERE -indoors and outdoors. They serve an important, positive role, by helping to break down organic matter. There are more than 100,000 species of mold. At least 1,000 species of molds are common in the U.S.

Some of the most common molds found are species of Cladosporium, Penicillium, and Aspergillus. Mold is most likely to grow where there is water or dampness -- such as in bathrooms and basements.

How can molds affect your health?
The most common types of mold are generally not hazardous to healthy individuals. However, people who have asthma, hayfever, or other allergies or have weakened immune systems are more likely to react to mold. The most common symptoms are running nose, eye irritation, cough, congestion, and aggravation of asthma. A small percentage of the population can develop more serious effects -- such as fevers and breathing difficulties -- but these effects are uncommon. Some types of mold can cause more serious health problems, but this is much more rare.

How can you be exposed to mold?
When moldy material becomes damaged or disturbed, spores (reproductive bodies similar to seeds) can be released into the air. Exposure can occur if people inhale the spores or directly handle mold-containing material and accidentally ingest it. Some molds can produce chemicals called mycotoxins. Mycotoxins may cause illness in persons who are sensitive to them (for example, persons who are prone to allergies) or when persons are exposed to large amounts in the air (typically associated with certain occupations).

What is Stachybotrys Chartarum?

Stachybotrys chartarum (SC) ( also known as Stachybotrys atra) is one mold that is associated with health effects in people. SC is a greenish-black mold that can grow on materials with a high cellulose content (such as drywall sheetrock, dropped ceiling tiles, and wood) that become chronically moist or water-damaged, due to excessive humidity, water leaks, condensation, or flooding. SC is a relatively uncommon mold. SC spores do not become easily airborne; therefore, contamination of indoor air by SC is unusual.

How can you tell if SC is present in your home?
All mold needs water to grow. Mold can grow anywhere there is water damage, high humidity or dampness. Most often molds are confined to areas near the source of water. Removing the source of moisture, such as through repairs or dehumidification, is critical to preventing mold growth. Many molds are black in appearance but are not SC, for example, the black mold commonly found between bathroom tiles. SC can only be positively identified through microscopic exam or by specially trained professionals.

How can SC affect your health?
Typically, indoor air levels of SC are low; and therefore not generally hazardous to health. However, as with other molds, at higher levels health effects can occur. These include allergic rhinitis (cold like symptoms), dermatitis (rashes), sinusitis, conjunctivitis, and aggravation of asthma. Some related symptoms are more general, such as inability to concentrate and fatigue. Usually symptoms disappear after the contamination is removed.

There has been some evidence linking SC with pulmonary hemosiderosis, a condition that causes bleeding in the lungs of infants generally less than six months old. This is a very rare condition. In cases of hemosiderosis, the exposure to SC came from highly contaminated dwellings, where the infants were continually exposed over a long period of time.

What should you do if mold is present in your home or apartment?
Although any visible mold can be tested by an environmental consultant and/or analyzed by a laboratory specializing in microbiology, these tests can be very expensive -- from hundreds to thousands of dollars. There is no simple and cheap way to sample the air in your home to find out what types of mold are present and if they are airborne. As noted above, even if you had your home tested, it is difficult to say at what levels molds would cause health effects. Therefore, it is more important get rid of the mold rather than find out more about it. The most effective way to treat mold is to correct underlying water damage and clean the affected area.

How should mold be cleaned?
Mold should be cleaned as soon as it appears. Persons cleaning mold should be free of symptoms and allergies. Use a common household bleach and water mix (1 part bleach to 10 parts water) to clean it. You can add a little dish soap to the bleach and water mix to cut any dirt and oil on the wall that can hold mold. Do not add ammonia. This can result in dangerous vapors. Apply the bleach and water mix to the surface with a sponge, let it sit for 15 minutes, then thoroughly dry the surface. Dispose of any sponges or rags used to clean mold.

If the mold returns quickly or spreads, it may indicate an underlying problem such as a leak. Any underlying water problems must be fixed to successfully eliminate mold problems. If mold contamination is extensive, a professional abatement company may need to be consulted.

Will my health or my child's health be affected and should we see a physician?
If you believe that you or your children have symptoms that you suspect are caused by exposure to mold, you should see a physician. Keep in mind that many symptoms associated with mold exposure may also be caused by many other illnesses. You should tell your physician about the symptoms and about when, how, and for how long you think you or your children were exposed.

Who can I call if I suspect I have a mold problem or if I want more information?
For more information about the health effects of mold exposure and information on the safe removal of mold, please call the New York City Department of Health, Bureau of Environmental Investigations at (212) 442-3372 or the Bureau of Environmental and Occupational Disease Prevention at (212) 788-4290.

December 1998