The CDC is investigating and evaluating the health effects of and quantifying the risks associated with, exposure to mold and poor indoor air.

There are a number of barriers that need to be overcome in investigating the possible effects of molds on health. Presently, no accepted standards for mold sampling in indoor environments or for analyzing and interpreting the data in terms of human health.

Molds are ubiquitous in the environment, and can be found almost anywhere samples are taken. It is not known, however,
what quantity of mold is acceptable in indoor environments with respect to health.

Because of difficulties related to sampling for mold, most studies have tended to be based primarily on baseline environmental data rather than human dose-response data.

For these reasons, and because individuals have different sensitivities to molds, setting standards and guidelines for
indoor mold exposure levels is difficult and may not be practical.

The State of the Science according to the CDC

Molds and Human Health

In addition to the challenges presented to monitor mold due to no generally accepted standards for mold sampling in indoor environments or for analyzing and interpreting the data, there are challenges defining the effects mold has on human health. Other than surveillance for hospital-acquired infections, there currently is no system to track the public’s exposure to and the possible health effects of mold.

Exposure to mold does not always result in a health problem. However, routine measures should be taken to prevent mold growth indoors because some people are, or may become, allergic to it.

For people who are allergic to mold, common effects include hay-fever-like allergic symptoms.

Certain individuals with chronic respiratory disease (chronic obstructive pulmonary disease or asthma) may experience difficulty breathing when exposed to mold.

Also, people with immune suppression or underlying lung disease are more susceptible to fungal infections.

Summary of the Statement on the CDCs activity on mold and health

People who are exposed to molds may experience a variety of illnesses.

Fungi account for 9% of nosocomial infections, that is, infections originating or taking place in ahospital.

Ingestion of foods contaminated with certain toxins produced by molds is associated with development of human cancer.

Many respiratory illnesses among workers may be attributed
to mold exposures.

Uncommon illnesses that collectively can be called hypersensitivity
pneumonitis are caused by chronic exposures to high concentrations of mold and are almost exclusively limited to certain agricultural workers in particularly moldy environments.

Common illnesses caused by molds include allergic conditions such as hay fever and asthma.

· CDC is planning an occupational and environmental research project regarding bioaerosols in schools to address children’s and teacher’s health issues.

· CDC is working to address indoor air quality issues, including mold, in partnership with stakeholders through the National Occupational Research Agenda (NORA). NORA efforts have resulted in development of the research priorities paper, “Improving the Health of Workers in
Indoor Environments: Priority Research Needs for a National Occupational Research Agenda,” which identifies important areas for future research. The paper has been accepted for publication
in the American Journal of Public Health (AJPH).

Summary of the Statement on the CDCs activity on mold and health

Because molds can be harmful, CDC concurs with the general recommendations of agencies such as EPA and FEMA, which offer information on preventing and cleaning up mold growth in
indoor environments.

Linkages between indoor airborne exposures to molds and other health effects, such as bleeding from the lung, or memory loss, have not yet been scientifically substantiated.

CDC and other organizations are taking steps to fill the gaps in our knowledge about linkages between exposure to mold and human health.

Statement for the Record
Before the Subcommittees on Oversight and
Investigations and Housing and Community
Opportunity

Committee on Financial Services
United States House of Representatives
State of the Science on Molds and
Human Health

Statement of Stephen C. Redd, M.D.
Chief, Air Pollution and Respiratory Health Branch
National Center for Environmental Health
Centers for Disease Control and Prevention,
U.S. Department of Health and Human
Services

Released July 18, 2002
State of the Science on Molds and Human Health July 18, 2002

The State of the Science according to the CDC

Outbreaks of hypersensitivity pneumonitis also have been reported in office buildings in relation to exposures to mold-contaminated humidifiers and ventilation systems.

(Arnow et al. 1987. Early detection of hypersensitivity pneumonitis in office workers, American Journal of Medicine 64:236-242 and Hodgson et al. 1987. An outbreak of recurrent acute and chronic hypersensitivity pneuomonitis in office workers. American Journal of Epidemiology 125:631- 638)

Molds can cause illness when people are exposed to extensive mold growth indoors.

In its 1993 report “Indoor Allergens,” the Institute of Medicine (IOM) concluded that airborne fungal allergens were most often associated with allergic diseases, such as allergic rhinitis/conjunctivitis, allergic asthma, and hypersensitivity pneumonitis.

Potential Results of Mold Exposure

The EPA stated in 1991, "The term "Sick Building Syndrome" (SBS) is used to describe situations in which building occupants experience acute health and discomfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. The complaints may be localized in a particular room or zone, or may be widespread throughout the building. In contrast, the term "Building Related Illness" (BRI) is used when symptoms can be attributed directly to airborne building contaminants."

Disease Due to Fungal Toxins

Far less common but far more feared are the diseases due to fungal toxins. These diseases provoke significant anxiety due to their potential to cause dramatic consequences. However, there is currently a great deal of overblown fear and legal attention to environmental fungal toxins. The American College of Occupational and Environmental Medicine (ACOEM) has an excellent fact-based position statement on this topic.For excellent reviews on this topic, consult Kuhn and Ghannoum or Bennett . Almost all real episodes human illness due to fungal toxins have followed ingestion of the toxin. Perhaps the best known of the ingestion syndromes is ergotism, a syndrome known for hundreds of years. It may present with limb gangrene, hallucinations, and death and thus can be quite dramatic. It is a vasospastic disorder caused by ingestion of rye products contaminated with ergot
American College of Occupational and Environmental Medicine (www.acoem.org), Arlington Heights,IL.

CDC efforts to evaluate the health problems associated with molds

CDC has conducted several activities related to mold in wet indoor environments and its effect on people’s health.

·In 1994, CDC conducted two epidemiologic investigations of reported clusters of the acute onset of bleeding from the lungs of very young children (pulmonary hemorrhage or idiopathic pulmonary hemosiderosis).

In one investigation a possible association was reported between exposure to the mold Stachybotrys atra (S. atra) and disease.

This association was not reported in the second investigation. In a further review of our first investigation, CDC reviewers and an external panel of experts determined that there was insufficient evidence of any association between exposure to S. atra or other toxic fungi and idiopathic pulmonary hemosiderosis in infants.

CDC has plans to further evaluate the relationship between pulmonary hemorrhage and S. atra through state-based urveillance, further investigations of identified disease clusters, and
focused research studies.

·In July 2001, following flooding in North Dakota, CDC investigated Turtle Mountain Reservation residents’ concerns that mold contaminating their homes might be contributing to an increase in illness among tribal embers.

CDC assessed both the physical and environmental condition of the homes to identify any environmental hazards, including the presence of mold, and collected information on health conditions of the individuals living in the homes.

An interim report identified several existing hazards unrelated to mold and made recommendations to address these hazards. The final report is expected in October 2002. In addition to working with the Indian Health Service and the Federal Emergency Management Agency (FEMA) on this project, CDC also worked with the U.S. Department of Housing and Urban Development (HUD) to identify procedures that might be implemented to assess conditions of HUD homes that would help to prevent mold.

· CDC responded to a request from the State of Texas and the City of Houston in the summer of 2001, after the city experienced significant flooding, to assess the conditions of the buildings and provide advice on cleanup and repair of affected buildings. The emphasis of this technical
assistance was cleanup and prevention of further mold growth and prevention of unnecessary exposure.

· In 1999, CDC’s occupational health experts began a 5-year initiative on work-related asthma in offices and schools, with an emphasis on moisture and mold exposures.

A research program regarding work-related asthma was targeted that includes evaluations of workplaces, intervention studies, and recommendations for reducing the risk of respiratory disease, and
provision of information to management, employees and environmental health and safety professionals.

The research aims are targeting problem buildings identified through the CDC’s occupational Health Hazard Evaluation program.

Specific objectives include methods development and testing, specifically with regard to state-of-the-art techniques for assessing indoor air quality-related exposures; quantification of objective medical indices related to asthma and other lung diseases; and planned case-control, cross-sectional, and intervention studies directed towards risk factor identification and assessment.

The results include the following:
· there were significant relationships between reports of work-related respiratory disease and visual assessment of water and mold-damage in two studies;
· there were significant relationships between endotoxin and ultra-fine particles in air and work-related respiratory symptoms; and
· there were significant relationships between indicators of mold in chair and floor dust and work-related respiratory symptoms.

CDC’s collaborations with other Federal agencies

CDC is working with federal, state, local, and tribal governments to investigate and respond to mold-related problems. The CDC is working with HUD, FEMA, and the Indian Health Service on mold issues.

The CDC is assisting the U.S. Environmental Protection Agency (EPA) Indoor Environments Division in the development of a guide for mold remediation in schools and large buildings and in the development of a brief guide to mold for
homeowners.

CDC is participating in the development of a World Health Organization guidance document on exposures to biological agents in the indoor environment; this document should be finalized in the year 2003.

CDC also has worked with the Council of State and Territorial Epidemiologists in the development of case definitions and classifications for pulmonary
hemorrhage in infants.

CDC’s collaboration with the Institute of Medicine (IOM)

One such collaboration is with the Institute of Medicine (IOM). The CDC is funding the IOM to evaluate the relationship between damp or moldy indoor environments and the manifestation of adverse health effects. Under this project, the IOM will conduct a comprehensive review of the scientific literature; the review will focus on respiratory and allergic symptoms and other non-allergic health effects. The IOM summary will include recommendations or suggest guidelines for public health interventions and future research.

The IOM initiated their study in January 2002 in response to concerns about mold and the gaps in scientific knowledge; The CDC is currently developing an agenda for research, service, and education related to molds, and collaborating with other research bodies to more effectively understand how mold affects humans.

The results of this effort will ultimately enable CDC to
(1) make recommendations for reducing mold contamination,
(2) identify environmental conditions that contribute to the occurrence of disease following mold exposure, and
(3) assist state and local health departments in improving their capacity to
investigate mold exposures.

CDC is working to help strengthen state and local capacity to respond to requests regarding molds. Because there are no quantitative standards, guidelines or uniform recommendations for responding to mold in indoor environments, each state or local health department responds to public inquiries based solely on its own experience.

Another collaboration, the CDC is working with the Council of State and Territorial Epidemiologists to:

· develop an inventory of state Indoor Air Quality programs;
· determine the extent to which these programs are coordinated to respond to issues related to indoor mold exposures;
· identify resources that states need in order to develop and implement appropriate responses; and
· develop a coordinated public health response strategy to mold exposure.

The CDC is investigating and evaluating the health effects of and quantifying the risks associated with, exposure to mold and poor indoor air. Despite the lack of standards, CDC concurs with EPA’s recommendation to remedy mold contamination in indoor environments to prevent negative health effects. The American College of Occupational and Environmental Medicine (www.acoem.org), is also studying the adverse affects of mold exposure.

The expectation is that such studies will help to identify the environmental factors and antecedents associated with mold contamination and factors that determine poor health outcomes.

For example, The CDC is developing a protocol for investigating the possible health effects of exposure to mold in indoor school environments.

The CDC will use the knowledge, experience and skill gained from these investigations and evaluations to translate science-based findings into appropriate public health interventions to reduce any health
risk found to be associated with mold exposure.