We are frequently asked questions by our patients concerning either school or work environment and their illnesses. Indoor air quality is an important health concern, since we generally spend 90% of our time indoors. In addition, more than half the work force now works primarily in office or other commercial buildings.
We like to use the term "building related illness" to describe the entire spectrum of diseases which are acquired in the indoor environment. Building related illnesses may be divided into two broad categories. The first group is well characterized by certain symptoms and laboratory findings. Examples of these diseases include hypersensitivity, pneumonitis, humidifier fever, asthma, and various respiratory infections. The second major group of building related illnesses is termed the "Sick building syndrome," in which no laboratory abnormalities have been found and no single cause has bee identified. Overall, a specific cause, such as a bacterial contamination of the humidification system or accumulation of motor vehicle exhaust can be found in approximately 25% of apparent outbreaks of building related illnesses. The remaining 75% are unexplained and are considered to be attributed to the sick building syndrome.
One of the specific building related illnesses that we as allergists frequently encounter are asthma and sinus diseases. Most reported cases of building related asthma have been related to exposure to contaminated humidifiers or to allergic reactions to the biocides that are used in the humidifiers. Likewise, nasal allergies and chronic sinusitis may be caused by a specific exposure to allergens in the work environment, such as molds or dust mites. Conditions of low temperature and/or low humidity as well as indoor irritants as formaldehyde, tobacco smoke and perhaps volatile organic compounds and mineral fibers may trigger asthma symptoms in people with pre-existing lung allergies.
Exposure to toxins and irritants in the work place may lead to significant respiratory illness. Symptoms of carbon monoxide poisoning for example can arise when air intakes for building ventilation systems are located near parking garages or down wind from large boiler stacks. Common sources of toxins and irritants include finishing materials, cleaning agents, construction materials, office equipment and furnishings, tobacco smoke and combustion products. Formaldehyde, found in resins and glues used in plywood is another common source of indoor air problems.
A remarkably consistent pattern of complaints from office workers began to surface in the 1970s. This was subsequently called the "Sick Building Syndrome." These symptoms actually began during the time of the energy crisis, and newly constructed or remodeled buildings were being designed with energy efficiency in mind. Most of these buildings had no windows that open to the outside air and any air exchange was provided only through air conditioning systems. Also at that time, the ventilation standards for indoor air was lowered from 20 cubic feet per minute per occupant to five cubic feet per occupant. As a result, workers illnesses soon were attributed to lower rates of ventilation and consequent inadequate dilution of irritants. Many of the workers complained of their eyes, nose and throat being irritated and they also suffered from frequent headaches and had difficulty concentrating. Similar complaints are being heard today in the WOrld Health Organization which estimates that nearly 30% of newly constructed or remodeled buildings are associated with health problems.
The diagnosis of building related illness often presents a major challenge to your doctor. The work-up may be extremely extensive and expensive requiring a whole team of specialists including occupational medicine physicians, epidemiologists, psychiatrists, psychologists, toxicologists, building engineers, architects, and building maintenance supervisors. Unfortunately, despite this very intensive investigation, the actual cause and diagnosis is frequently not made and may end up in a very complex legal mess.
Individuals with illness that seems to be related to building exposure represent a difficult challenge to physicians. It is imperative that we do not prematurely dismiss workers' complaints because by doing so an opportunity to identify and alleviate a specific cause of the illness may be missed.
Written by Allergy Care physician, Dwight Lindsay, M.D.