Sick Building Syndrome

Sick building syndrome is a cluster of nonspecific symptoms that occupants of a particular building experience in proportion to time spent in it. No specific illness or cause can be identified, and symptoms resolve soon after leaving. Surveys of office workers find that 10 to 30% report symptoms in some buildings, and the prevalence is higher in air-conditioned buildings than in naturally ventilated ones.

It is distinct from building-related illness, in which a specific disease with a clinical and laboratory signature is linked to a building (hypersensitivity pneumonitis, Legionnaires disease, humidifier fever and occupational asthma).

Contributors

• Inadequate ventilation (fresh air supply under 8 L/s for each occupant) and poorly maintained air conditioning
• Volatile organic compounds and formaldehyde from new furnishings, carpets, paints, adhesives and cleaning products
• Dust, fibers and particles from photocopiers and printers
• Temperature outside 20 to 24 degrees Celsius, humidity outside 40 to 60%, glare and noise
• Psychosocial factors: low job control, high demand, poor communication and stress

Women, atopic people and workers in clerical roles report more symptoms. The mechanism is multifactorial, with sensory irritation and psychological factors playing a part. Symptoms improve when ventilation, cleaning and management factors are corrected. Complications: reduced concentration and productivity, absenteeism and low morale.

• Headache, fatigue and difficulty concentrating
• Irritation of the eyes, nose and throat, dry cough, hoarseness, and dry or itchy skin
• Dizziness, nausea and sensitivity to odors
• Symptoms that appear during the workday, worsen with time in the building, and improve within hours of leaving or on weekends
• Several employees affected in the same area
• Red flags: fever, productive cough or dyspnea (consider building-related illness), neurological signs, a cluster with carbon monoxide risk, and wheeze

Sick building syndrome is a diagnosis of exclusion.

1. Symptom survey and history: work location, timing, number of affected staff, recent building changes (renovation, new carpets, cleaning products) and relation to ventilation.
2. Clinical examination and basic tests: peak flow diary, spirometry and allergy testing if asthma or allergy is suspected.
3. Exclusion of specific disease:
   • Carbon monoxide (carboxyhemoglobin, and building detectors) for headache and dizziness clusters.
   • Hypersensitivity pneumonitis (chest imaging and precipitins) and Legionnaires disease (urinary antigen and water testing) for febrile or respiratory illness.
   • Occupational asthma and rhinitis, infection and thyroid disease.
4. Building investigation by hygienists and engineers:
   • Ventilation rate and carbon dioxide concentration (a reading over 1000 ppm indicates under-ventilation).
   • Temperature and relative humidity.
   • Volatile organic compounds and formaldehyde measurements.
   • Particle counts, microbial sampling and inspection of ducts, filters and humidifiers.
   • Water system testing for Legionella.
5. Assessment of psychosocial factors using validated questionnaires.

Differentials: building-related illness, carbon monoxide poisoning, allergic rhinitis, occupational asthma, viral infection and non-occupational headache disorders.

1. Remediation of the building:
   • Increase the supply of outdoor air to at least 10 L/s for each occupant.
   • Clean and maintain ventilation systems, filters, ducts and humidifiers regularly.
   • Keep temperature at 20 to 24 degrees Celsius and relative humidity at 40 to 60%.
   • Remove or limit sources of pollutants, and use low-emission materials and cleaning products.
   • Fix water leaks and treat mold.
   • Airing new furnishings before occupation.
2. Workplace organization: improve job control, communication and breaks, improve lighting and noise, and provide clear information to employees.
3. Symptomatic measures for affected workers:
   • Saline nasal spray 2 sprays in each nostril as needed for dryness.
   • Carboxymethylcellulose 0.5% eye drops, 1 drop in each eye 4 times daily.
   • Emollient to dry skin twice daily.
   • Paracetamol 1 g orally every 6 hours (maximum 4 g a day) for headache, avoiding frequent use.
4. Avoid unnecessary medication and further tests, and offer reassurance that no serious disease is present.
5. Temporary relocation of those most affected while remediation is carried out.
6. Monitoring of symptom scores before and 4 to 12 weeks after changes.
7. Escalation: if a specific disease is found, manage it as building-related illness, with investigation of the cluster and exposure control.

Follow-up at 4 to 8 weeks with repeat surveys. Counsel that most symptoms settle after corrections, and that early reporting by staff aids detection.