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Allergy & Asthma Advocate: Fall 2005
Mold in schools: the importance of school indoor air quality and its affect on asthmaBy Christopher Randolph, MD, FAAAAI Mold is a type of fungi, usually growing on damp or decaying surfaces. It can be found in any location and on any substance, provided that there is presence of moisture. Usually relative humidity over 50% is required, as well as oxygen and light for growth of mold. Mold is the most common outdoor airborne allergen and plays a key role in the breakdown of leaves, wood and other plant debris. Mold is essential to the digestion of large amounts of dead plant material that would otherwise be difficult to remove. Molds elaborate tiny spores as part of reproduction. These spores can travel indoors and outdoors and can deposit on surfaces and begin the process of growing and digestion wherever they survive. Molds are commonly found in indoor environments such as schools on wood surfaces, paper, carpets, and foods. Their growth is favored by excessive moisture or water accumulation. While it is impossible to eliminate all molds or mold spores indoors, control of mold is largely by control of moisture. If there is a problem with mold in a school, the best way to handle this problem is to bleach the surface and reduce the level of moisture to less than 50% humidity. 
Mold growth that occurs in buildings has been associated with health problems, ranging from respiratory problems, cough and wheezing to headache, fatigue, weakness and even gastrointestinal symptoms. There is excellent evidence that mold worsens existing allergy and asthma symptoms, particularly common molds, indoor and outdoor. Examples include Alternaria, but also Aspergillus and Penicillium, which are indoor molds, and Basidiospores, which are mushroom molds that have been associated with increased incidence of asthma presenting to the Emergency Room. Mold problems have been associated with tight building construction begun in the past 20-30 years when there was a fuel crisis. Tightly sealed buildings do not allow moisture to be released easily. Furthermore, moisture problems are related to poor or insufficient maintenance of heating, ventilation and air conditioning systems, related to financial constraints in school systems. Temporary structures within schools such as trailers or portable classrooms have been associated with moisture and mold and related conditions. For the management of mold problems in schools, vist the Web site http://www.epa.gov/IAQ/schools/asthma/EAT-CUMCM.htm or www.EPA.gov/asthma. The primary mode of management of mold growth in the school is to reduce indoor humidity by venting showers and other moisture generating sources to the outside, controlling levels of dampness and humidity by using air conditioners and dehumidifiers and providing ventilation to maintain indoor humidity levels between 30% and 60%. The use of exhaust fans in areas where there is cooking or dishwashing or cleaning, as in food service areas, is essential. Buildings should be checked for signs of mold, moisture, leaks or spills. The school site should be checked for moldy odors, water stains or discoloration on the ceilings, walls, floors and window sills. Previous studies have shown that favorite spots for mold growth are windowsills, sinks (particularly in kitchens), and heating, ventilation and air conditioning systems where moisture can collect. Inspection should be made of areas under and around sinks for standing water, water stains or mold in bathrooms and avoidance of standing water in air conditioning and refrigeration drip pans. Prompt response is required when signs of moisture and/or mold are noted or when there are leaks or spills. Any damp or wet building materials or furnishings should be cleaned and dried within 24-48 hours in order to prevent mold growth. The source of a water problem or leak should be addressed to prevent growth of mold. Removal of mold from hard surfaces with water and detergent and complete drying is essential. Absorbant material such as ceiling tiles that are mold ridden may need to be replaced. The mechanical room and roof need to be evaluated for unsanitary settings, leaks or spills. Finally, one can prevent mold condensation by reducing the potential for condensation on cold surfaces such as windows, piping, exterior walls, roofs and floors by adding insulation. Floor and carpet cleaning is essential. Spots and stains should be cleaned and removed immediately, using floor manufacturer's recommended techniques. Care should be utilized to minimize excess moisture and removing residual accumulation and assure that clean areas are dried rapidly. In areas where there is a continuous moisture problem, do not install carpets, i.e. drinking fountains, classroom sinks or on concrete floors where there are leaks or frequent condensation. Finally, the action items cited above are included on the checklist found in the Indoor Air Quality Tools for Schools Action Kit, located in the Asthma Management and Education section of the Environmental Protection Agency Web site, www.wpa.gov. The Action Kit includes a ventilation checklist, building maintenance checklist, administrative staff checklist, teachers' checklist, food service checklist and renovation and repair checklist. Individuals with asthma who are exposed to obvious mold growth need to be properly managed and evaluated by a board-certified allergist/immunologist. Skin testing and spirometry testing to diagnosed allergies and asthma is essential. Management with inhaled corticosteroids, intranasally and into the oral airway, as well as proper use of non-sedating antihistamines and allergen immunotherapy, where needed, are essential methods of management. The initial management requires addressing the moisture problem and eliminating it, as above, and minimizing mold by minimizing moisture and bleaching areas that can be bleached with diluted solution 2.4% hypochloride bleach and removal of those mold-ridden items that cannot be remediated. All school evaluations should be done by professional industrial hygienists and indoor air consultants in conjunction with the Occupational Safety and Health Administration (OSHA) and clean up should be done only by properly equipped and outfitted indoor air specialists. This may require moving the students, teachers or administrative individuals and should be done under the guidance of a professional indoor air consultant. |
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