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Sick building syndrome (SBS) refers to respiratory health problems in office workers that are not attributable to industrial activity. SBS is emerging as a critical health, environmental, and legal issue.
Epidemiology and Contributing Factors
The definition, epidemiology, and precipitating events of the symptom complex help to distinguish it from other defined building-related illnesses such as occupational lung diseases or hypersensitivity pneumonitis, which can be traced to a single compound or allergen (e.g., asbestos, mold). Some physicians, however, feel that SBS is a pseudodiagnosis composed of nonspecific transient symptoms without proven findings.
Investigations of outbreaks have shown that a high proportion of workers is affected. Symptoms are nonspecific but often related to the respiratory tract and without apparent cause other than inadequate ventilation. Buildings in which the syndrome occurs often have poor arrangement of space, ample use of fabrics, dirty carpets, elevated room temperatures, and many smokers.
Complaints tend to come from patients in buildings with high occupant densities, forced ventilation systems, and energy-efficient architecture. Physical, chemical, biologic, and psychological factors that may play a role include poor heating high noise levels, poor lighting, high work-related stress, and a history of anergy or other medical conditions. Women are affected more often than men, and patients who are younger are at greater risk.
INDOOR AIR QUALITY. Although one might believe that the air inside buildings is much cleaner than the air outside, indoor air can often be more polluted. Poor quality indoor air has been linked to problems that range from acute respiratory irritation to cancer. Studies have shown that SBS is not caused simply by poor quality air but results from the combined effects of various physical and nonenvironmental factors. Building occupants are exposed to diverse products and processes that include human expiratory gases, cosmetics, fragrances, deodorants, tobacco smoke, ozone, oxidation products from plastics, contaminants from building components and machinery,, and spores and other allergens. In addition, carbon monoxide, sulfur dioxide, and nitrogen oxides generated by faulty combustion systems or automobile exhaust.
VOLATILE ORGANIC COMPOUNDS are generated by photocopiers, carpets, and furnishings as they are used or when components oxidize; compounds include acetone, benzene, benzaldehyde, benzyl acetate, toluene, and xylene. One irritant, formaldehyde, is present in hundreds of office components, including wood and laminated furniture, shelving, and wall covers. It also evaporates from paints, varnishes, and chemicals used for sealing and finishing walls.
Allergens produced by molds and fungi can cause hypersensitivity pneumonitis (e.g., air conditioner's lung) but often contribute to SBS. The organisms are ubiquitous and can be introduced into buildings in dirt and dust during construction, internal operation of contaminated equipment, and flooding or water damage from broken pipes, leaks, or condensation. Common sites for mold and fungi are humidification systems, wet insulation, and carpets, where they can grow unnoticed; other sites include the paper covering plasterboard, wallpaper, and ceiling tiles.
Symptoms and Diagnosis
Symptoms are mostly nonspecific, mild, and related to the respiratory tract. They include headache, dizziness, upper respiratory irritation (rhinitis, itchy or watery eyes, scratchy throat, sneezing, Coughing, shortness of breath), nausea, lethargy, inability to concentrate, listlessness, and fatigue. Patients who complain of symptoms also perceive that they have little control over their physical environment. Although objective physiologic abnormalities are not generally found.
The diagnosis requires that symptoms improve on days away from the building; however, this underestimates some symptoms that take longer than a weekend to resolve. Objective tests are not available for most complaints and diary cards.
Modern Architecture and Related Conditions
Modern architecture has led to the development of SBS. Newer buildings tend to be more tightly sealed and ventilated, heated, and air conditioned with duct systems that facilitate buildup of pollutants. New buildings can have fan coil units or may rely on natural ventilation; however, exposure to conditioned air has led to specific building-related problems.
Typical problems with air conditioning include improper setup, unexpected alterations, obstructed inlets and outlets, unanticipated changes in loading factors, distribution perturbations, and contamination. Design changes can result in areas that do not have adequate air turnover (dead spots) as well as places with irritating drafts. Improperly cleaned and maintained ventilation systems can contribute to SBS, and increased air recirculation can exacerbate SBS ff molds, fungi, or insects are present. Whenever possible, ventilation improvements and reduction of environmental contamination.
Humidifier fever is a typical complaint in some settings that may be confused with SBS. The former is associated with flu-like symptoms and breathing difficulties caused by infectious agents in stagnant water in some internal humidifier reservoirs. The condition occurs more often in print shops and other manufacturing plants where the air.
Evaluation and Therapy
A first step in evaluating a suspicious building is to survey the occupants to identify particular symptoms. Questionnaires can also help document the patients' perception of the building's physical and psychosocial environment.
Many tests can assess indoor air quality. Typical measurements include humidity, temperature, and levels of carbon dioxide, dust, fungi, microorganisms, dust mites, and fiberglass and other fiber fragments. Because carbon dioxide is an indicator of ventilation efficiency, the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE).
Indiscriminate testing can result in misleading, irrelevant, and uninterpretable data. Thus, selected measurements may be more helpful in assessing potential etiologic agents; SBS usually has a multifactorial etiology. Useful measurements include temperature, relative humidity, and carbon dioxide levels. Measurements of respirable particles, chemicals, bioaerosols, and allergens should be performed only after medical conditions attributable to SBS have been identified.
One case reported by T. Metso and colleagues, involved five family members who lived in an apartment building and had experienced respiratory symptoms. Laboratory tests revealed elevated levels of myeloperoxidase.
Treatment: A biopsychosocial approach is recommended for understanding SBS. Medical therapy is palliative. Symptomatic treatment can be beneficial; however, medical treatment may obscure undiagnosed conditions and result in unwanted side effects.