Not everyone who works in a sick building will become sick, just as the whole population does not succumb to a bout of the flu during an epidemic. There are many factors that determine a person's physical response to their environment, although the response in sick building syndrome is rarely so severe that the person needs to take sick leave.
People who have become sensitised to a particular allergen (such as the house dust mite which provokes an attack of asthma in sensitive individuals) can be affected by very small amounts of that agent. Some substances are more likely than others to cause allergy, but any organic substance is a potential allergen.
A US company that specialises in remedying sick buildings carried out research which showed that allergenic fungi were the main pollutants in 34 per cent of mechanically ventilated buildings (Guardian 1988).
See also Asthma, Humidifier fever
Symptoms that are suggestive of work-related asthma include chest tightness, difficulty in breathing, shortness of breath and wheezing. Someone who is told by their general practitioner that they have recurrent bronchitis may in fact have occupational asthma. Breathing difficulties that improve on days away from the workplace could be due to occupational asthma.
'I teach computer studies in a room which, I feel, has made me develop asthma and which, latterly, has given me severe headaches. A colleague has suggested that I should use an ioniser in the room. If you know of any medical evidence that would substantiate my claim I would appreciate it. At the moment I am just told to keep taking the Becotide (for the asthma) and Paracodol (for the headaches).' (Ballyclare, County Antrim)
In one study, up to 10 per cent of workers in air-conditioned offices with humidification experienced chest tightness compared with about 2 per cent of those in buildings with natural ventilation (Finnegan et al 1984).
Work-related asthma may be caused by an allergic reaction to inhaled micro-organisms or their toxic products (Morris 1987).
See also Allergy, Humidifier fever
Breathing difficulties
See Asthma
Chest infections
A high frequency of airways infection is one of the features of the sick building syndrome described by the World Health Organization (1983).
See also Respiratory infections
Colds
See Respiratory infections
Cough
See Chest infections, Humidifier fever, Sick building syndrome
The sensitivity of the eyes to the atmosphere means that they are easily irritated, and symptoms such as soreness, itchiness, grittiness, watering and redness are common in buildings with indoor climate problems. Some of these symptoms are due to dryness, whereas others (watery eyes) may be an allergic response.
Tests for 'dry eyes' have shown that people who report building-related eye symptoms may have unstable tear-films and damaged conjunctival epithelium (Franck 1986).
Eye problems often occur together with nasal and throat problems.
See also Sick building syndrome
See Nausea
Extrinsic allergic alveolitis
The alveoli are the tiny airways at the bottom of the lungs where exchange of gases takes place. In extrinsic allergic alveolitis, these airways become inflamed as a result of an allergic response to an inhaled allergen. The illness is similar to farmers' lung, where the allergen is fungal spores. Symptoms are similar to those of humidifier fever - fever, chills, cough, malaise, chest tightness and shortness of breath - except they do not disappear because tolerance does not develop. Additional, long-term symptoms include loss of appetite, weight loss and a persistent cough with sputum which can lead to permanent lung damage due to scarring (fibrosis).
Extrinsic allergic alveolitis due to organisms from humidification systems has been reported in a few people (Robertson and Burge 1985).
The headaches associated with sick building syndrome are most often felt across the forehead, above both eyes, and also at the back of the neck. They are not usually throbbing or associated with visual symptoms, as in migraine (Robertson and Burge 1985), and were described as 'usually mild' in one study (Finnegan et al 1984).
The headache, like the lethargy which often accompanies it, usually gets worse as the day progresses and starts to improve quite quickly once the person has left the building. Headache has many possible causes, including working all day under fluorescent lighting or spending too many hours in front of a visual display unit. It may be useful to keep a diary of when headaches occur to see if they are related to time spent in the building.
See also Humidifier fever
This is the American term for extrinsic allergic alveolitis.
Humidifier fever is caused by breathing in water droplets from humidifiers (or sometimes from other components of a ventilation system such as air filters) that have become heavily contaminated with micro-organisms. Such contaminated water can cause various illnesses, including respiratory infections and allergenic illnesses such as asthma and extrinsic allergic alveolitis. Humidifier fever is the most common and best documented of these illnesses (Sykes 1988). Sometimes a diagnosis of humidifier fever is made by testing sufferers for their reaction to extracts of the water or organic material taken from a contaminated humidifier.
Humidifier fever is a non-infective (that is, you can't 'catch' it from anyone else) building-related illness for which a specific cause can often be found, if it is looked for, unlike sick building syndrome which usually has non-specific causes. The disease has been reported more often in industrial buildings than in offices or public buildings, and is a particular problem in printing works where humidification needs are high and paper dust provides a good source of nutrients for microbes in the air-conditioning system.
The acute symptoms are very like those of flu - fever, cough, aching limbs, headache, tiredness and lethargy - although the symptoms don't usually last for quite so long. Some people who are particularly sensitive to the causative agent may also have asthmatic symptoms of tight chest and difficulty in breathing (see Table 1).
Symptoms usually develop on the first day back at work after the weekend or other break (the disease is sometimes called 'Monday fever'), and they are often worse after a longer break or after a period of air-conditioning plant shut-down. They start only after the person has been back in the guilty environment for some hours, perhaps in the late afternoon of the first day, and often become severe in the evening and night after the person has left work, lasting for 24-48 hours. Despite the fact that the person may continue working in the contaminated environment, the symptoms do improve, indicating that an allergic reaction may be involved.
Cold water humidification systems can become contaminated with a wide range of micro-organisms (algae, amoebae, bacteria and fungi) and the response may be to the organism itself or to toxins produced. humidification systems that spray tepid water into the air are most prone to cause humidifier fever. The treatment of humidification systems with biocides or other chemicals can make the situation worse, since the chemicals may also be toxic. Humidifier fever is said to occur in about 3 per cent of people working in offices where a humidifier in the air-conditioning system is in operation (Robertson and Burge 1985).
Permanent lung damage does not occur, although a few reports have been made of people who have developed the more serious condition extrinsic allergic alveolitis due to organisms from humidification systems (Robertson and Burge 1985).
See also Asthma
Problems associated with poor air quality at work are often put down by bosses as a hysterical reaction, particularly since clerical staff are more likely than managerial staff to suffer from sick building syndrome and more women than men are clerical workers (Wilson and Hedge 1987). Since sick building syndrome has been accepted as a 'definite entity' by the Health and Safety Executive and the World Health Organization, the label of 'hysteria' can be seen as evidence of ignorance.
The influenza virus, like other airborne infectious agents, can be spread around a building by the recirculation of air in a ventilation system. Symptoms of flu are similar to those of humidifier fever, although their expression is not work related and they tend to last longer.
People working in sick buildings tend to suffer more from respiratory infections.
Lethargy, described in dictionaries as 'morbid drowsiness', might also go under the headings of tiredness, lack of energy, apathy, mental fatigue and sleepiness. The feeling that it is a great effort to concentrate tends to develop in the afternoons but improves once the person goes outside the workplace - sometimes within minutes, sometimes within 2-3 hours (Robertson and Burge 1985).
For lethargy to be taken seriously as a work-related condition it may be best to keep a diary, scoring the lethargy on a scale from 0-7 every 2 hours. The lethargy experienced in sick building syndrome is often also accompanied by a headache.
Lethargy may be experienced by about 50 per cent of workers in buildings that are air conditioned, with or without humidification systems, although about 15 per cent of people working in naturally ventilated buildings also complained of this symptom in the same study (Finnegan et al 1984). Many causes have been suggested for the symptoms of headache and lethargy: lack of negative ions, lack of air movement, low humidity, ozone and carbon monoxide, formaldehyde from furniture and furnishings, too much time spent at a visual display unit, fluorescent lighting.
See also Humidifier fever, Sick building syndrome
If the air is dry, the mucous membranes of the nose will also be dried and the nose will feel 'stuffy'. Or the membranes may be irritated and inflamed (as in the allergic response seen in hay fever), so that the nose is runny and perhaps itchy or blocked.
Nasal problems are more common in mechanically ventilated buildings with chiller or humidification systems than in those without such systems, which in turn have more problems than naturally ventilated buildings (Finnegan et al 1984; Robertson et al 1985; Burge et al 1987). Stuffy nose and dry throat, eyes and skin, are thought to be due to working in an atmosphere with low relative humidity or moisture content. However, one study showed that humidity levels were adequate, casting some doubt on the reasons for the 'dryness' reaction (Robertson et al 1985).
Nasal problems often go hand in hand with throat and eye problems.
See also Humidifier fever, Sick building syndrome
Nausea and dizziness are included in the World Health Organization's (1983) list of symptoms associated with sick building syndrome, but not all researchers have found these problems to be any more common than in the general population (Wilson and Hedge 1987).
A dry atmosphere leads to an increased incidence of respiratory infections since the mucous membranes are dried out too. Upper respiratory tract infections, such as colds and influenza, are more common in air-conditioned offices than in naturally ventilated ones (Ruheoann 1985). This may be partly due to the fact that recirculation of air in the system will spread viruses around the building and partly due to the debilitating effects of sick building syndrome. The inhalation of contaminated water from humidification systems may also cause respiratory infections.
'I work in a building that has a second-hand air-conditioning system and I don't think it works properly. All of us have had cold after cold and sore throats and coughs galore. We all feel very tired and lethargic at the end of the day. The boss won't allow us to have the windows open - even in the summer. I always feel headachy and my lungs are craving for fresh air at the end of the day. It feels very claustrophobic in there sometimes.' (Electrical wirer of audio equipment, Salisbury, Wiltshire)
See also Humidifier fever, Sick building syndrome, Stress
Sick building syndrome
Since the symptoms of sick building syndrome are common in the general population, it is the pattern of their expression that points to the diagnosis: in sick building syndrome, symptoms are associated with being in a particular building and are relieved by leaving or staying away from that building. Table 1 shows two types of syndrome; one is a more allergic response in sensitive individuals. In addition, the World Health Organization (1983) lists the following symptoms of malaise:
- eye, nose and throat irritation
- sensation of dry mucous membranes and skin
- erythema
- mental fatigue
- headache
- high frequency of airway infection and cough
- hoarseness, wheezing, itching and unspecific hypersensitivity
- nausea, dizziness
In a study of 4373 people working in 46 buildings (Wilson and Hedge 1987), 80 per cent had symptoms of ill-health which they associated with being in their place of work. Twenty-five per cent experienced one or two symptoms only, but 29 per cent had five or more symptoms. Lethargy was the most common complaint (57 per cent), followed by stuffy nose (47 per cent), dry throat (46 per cent), headache (43 per cent), itching eyes (28 per cent), dry eyes (27 per cent), runny nose (23 per cent), flu-like symptoms (23 per cent), difficulty in breathing (9 per cent) and chest tightness (9 per cent).
This study also showed that people with clerical/secretarial jobs have 50 per cent more symptoms than those with managerial posts, and 30 per cent more than 'professionals'. The likely reasons for this are that clerical workers most often work in open-plan offices where there is less control over environmental conditions than in cellular offices; they are more tied to their desks, so that they are exposed to the same conditions for most of the working day, unlike managers who are usually more mobile; and they often do repetitive, visually demanding jobs that stress the body physically. (Clerical/secretarial work comes high on the ladder of stressful occupations.)
Women report symptoms more frequently than men, a difference that may be due to the fact that women are employed predominantly in clerical/secretarial jobs and men in professional/managerial posts. Also, women tend to be more aware of how they are feeling than men. Another suggestion for this gender difference is that women may be more prone to sick building syndrome because a dose-response relationship exists: women need a lesser dose of a chemical or pollutant to become ill (Jones 1989).
People working in air-conditioned buildings consistently show higher rates of sickness than those working in buildings that are naturally ventilated or that have mechanical systems of ventilation supplying ducted air but not cooling or humidifying it, although it may be pre-heated (Finnegan et al 1984; Robertson et al 1985; Burge et al 1987; Wilson and Hedge 1987; Wilson et al 1987). For all ventilation categories, workers in public sector buildings have consistently higher rates of building-related sickness than those in the private sector (Wilson and Hedge 1987).
Skin problems
Dryness of the skin affects exposed areas such as the face, lips, arms and hands. In one study it was found to be commoner in women, who found they had to use more moisturising cream after moving from a naturally ventilated to an air-conditioned building (Finnegan et al 1984). Other reported problems include rashes, blotches (erythema) and itchy skin.
See also Sick building syndrome
Stress
The acute problems associated with stress include headaches, digestive disorders, fatigue and lethargy, sleeping problems, skin disorders and a reduced immunological response (i.e. a decreased resistance to infection). Many of these symptoms are similar to those seen in sick building syndrome, so stress due to environmental and other factors should also be considered as a cause of sick building syndrome.
Throat problems
Dry throat and hoarseness are symptoms that indicate drying of the mucous membranes and are often found together with a stuffy nose and sore eyes. Throat and chest infections are more common in buildings with air quality problems.
See also Eye problems, Nasal problems, Sick building syndrome
Wheezing
See Asthma
Sick Building Syndrome: causes, effects and control - Chapter 2
© 1990 London Hazards Centre, Interchange Studios, Hampstead Town Hall Centre, 213 Haverstock Hill, London NW3 4QP, UK
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