Health problems related to working
in office type buildings
Health problems are usually divided in building related diseases and sick building syndrome. Building related disease include infectious diseases spread from the building services, such as Legionnaires’ disease, and diseases spread from worker to worker within a building, such as virus infections. They also include any toxic reactions to chemicals used within the building, or derived from fungae growing within a building. They will not be discussed further here. The sick building syndrome comprises a group of symptoms of unclear aetiology divided into mucous membrane symptoms related to the eyes, nose, and throat; dry skin; together with what are often called general symptoms of headache and lethargy. All these symptoms are common in the general population; the distinguishing feature which makes them part of the sick building syndrome is their temporal relation with work in a particular building. All except skin symptoms should improve within a few hours of leaving a problem building; dryness of the skin may take a few days to improve. Office workers are the easiest to study as there are few other confounding factors. Similar problems occur in other buildings, particularly schools, hospitals, and care homes. Problems with indoor air also occur in homes, particularly those with water damage. In Nordic countries the term sick building syndrome is also applied to domestic dwellings. The causes and remedies are often different in these situations, and will not be discussed further in this review.
A general feeling of tiredness is often the most prevalent symptom.1 It usually starts within a few hours of coming to work, and improves within minutes of leaving the building. Symptoms may be seasonal in northern climates, being worse in the winter months, suggesting a relation with sunlight. The typical headache is non-migrainous, rarely throbbing, usually described as dull, and often as a pressure on the head. In Scandinavia the associated symptom of heavy headedness is often prevalent. It is usually less frequent than the lethargy.
Mucous membrane symptoms
The most common symptom is the sensation of a blocked or stuffy nose. True rhinitis with sneezing and running of the nose is much less common. The latter are the typical symptoms of allergic rhinitis due to an inhaled allergen. A feeling of dryness of the throat, perhaps associated with increased thirst, is the next most prevalent mucous membrane symptom. It can be a particular problem in those who use their voice professionally, such as broadcasters or telephonists. Although dry eyes are the least prevalent mucous membrane symptom, it can cause particular problems in those wearing contact lenses, who may not be able to use them throughout the day. Objective signs include reduced foam in the inner epicanthus, and increases tear film break up time.
Dryness of the skin
Dryness of the skin is the most difficult symptom to elicit from questionnaires, which generally require a symptom to improve on days away from the building to be classed as a work related symptom. The more prolonged recovery of skin dryness may lead to its under-recognition. There is a specific facial rash related to VDU use which is very rarely identified, and may relate to precipitation of charged particulates onto the face.
IS THE PROBLEM “REAL”
There are many sceptics as to the validity of the sick building syndrome diagnosis. The name is confusing, as it is the workers rather than the building who suffer from the symptoms, but the cause is with the building and its services. There are few objective tests to validate the symptoms, the exception being those with dry eyes where objective validation is possible but difficult.Some regard the symptoms as psychological (implying that they don’t really exist). Lethargy is a psychological symptom, but yet can have organic (within the building) causes. The psychological versus organic debate does not produce much enlightenment or resolution of the problem.
There are a number of observations which have been reproduced in different surveys in different countries, which are as close to facts as it is possible to get. They are shown in box 1.
IS THERE A PROBLEM IN A PARTICULAR BUILDING?
Problems can easily get out of hand due to the organisation within a working group. To whom should an individual who perceives health related symptoms due to work in an office type environment turn? There is an association between the perception of poor indoor air quality and symptoms.For instance it is likely that the perception of dryness in the air relates more to increased temperature and particulates in the air than to water content; one study showed a fourfold reduction in perceived air dryness following air filtration, without changing the water content of the airIndoor air is often perceived as dry and stuffy, which can easily lead to the ventilation engineer being asked to solve the workers’ symptoms. Unfortunately there is no association between the sensation of air dryness and the water content of the air. The measurement of normal humidity if often used to show that the air is not dry, and that by implication the workers’ symptoms are not due to the building environment. Assessment of workers’ symptoms is the role of occupational health professionals, who should be involved at an early stage.
The first step is to visit the workplace and carry out a “walk through survey”. Obvious factors of gross overcrowding, poor cleaning, space management, water damage, and the occupancy of areas of a building not designed as workplaces can be identified without technology. A workforce questionnaire is the next step if there is doubt as to the “realness” and degree of the problem. The questionnaire aims to estimate the building symptom index, the average number of work related symptoms per worker. There are different questionnaires available; many are sufficiently robust for use.Box 2 shows a suitable one. If the building symptom index is outside the norms, further work is needed. Responding to complaints by measuring individual pollutants is rarely helpful.
In Nordic countries the MM questionnaire is frequently used. Unlike the questionnaires referenced above this does not provide a validated summary measurement,but has been the tool for much useful indoor air research.
The principal factors shown to be associated with SBS are shown in box 3.
There are a number of individual exposures in the workplace which have been associated with symptoms; the most important are VDU use, paper use, and cigarette smoke.