The sick building syndrome (SBS) is used to describe a situation in which the occupants of a building experience acute health- or comfort-related effects that seem to be linked directly to the time spent in the building. No specific illness or cause can be identified. People affected may be localized in a particular room or zone or may be widespread throughout the building.
Residents of a building complain of symptoms associated with acute discomfort (headache; eye, nose, or throat irritation; dry cough; dry or itchy skin; dizziness and nausea;
difficulty in concentrating; fatigue; and sensitivity to odours). The cause of symptoms is not known and most of the afflicted residents report relief soon after leaving the building.
It is important to note that complaints may result from other causes. These may include an illness contracted outside the building, acute sensitivity (e.g., allergies), job related stress or dissatisfaction, and other psychosocial factors. [1]
Causes of sick building syndrome
Contributing factors to sick building syndrome are:
1. INADEQUATE VENTILATION
2. CHEMICAL CONTAMINANTS FROM OUTDOOR SOURCES – outdoor air that enters the building can be a source of indoor air pollution.
3. BIOLOGICAL CONTAMINANTS
Bacteria, molds, pollen and viruses may breed in stagnant water that has accumulated in ducts, humidifiers and drain pans, or where water has collected on ceiling tiles, carpeting, or insulation. Sometimes insects or bird droppings can be a source of biological contaminants.
Physical symptoms related to biological contamination include cough, chest tightness, fever, chills, muscle aches, and allergic responses such as mucous membrane irritation and upper respiratory congestion. One indoor bacterium, Legionella, has caused both Legionnaire’s Disease and Pontiac Fever.
These elements may act in combination, and may supplement other symptoms such as inadequate temperature, humidity, or lighting. However, even after a building investigation the specific causes of the complaints may remain unknown.1
Ways to prevent sick building syndrome
- INCREASE THE VENTILATION RATES AND AIR DISTRIBUTION. The heating, ventilation and air-conditioning systems should be designed to meet ventilation standards in the local building codes. If there are strong pollutants, the air may need to be directly vented to the outside. This method is especially recommended to remove pollutants that accumulate in specific areas such as restrooms, copy rooms and printing facilities. The American Society of Heating, Refrigerating and Air-Conditioning Engineers recommends a minimum of 8.4 air exchanges per 24 h.
- REMOVAL OR MODIFICATION OF THE POLLUTANT SOURCE (replacing water-stained ceiling tiles and carpets, using stone, ceramic or hardwood flooring, proper water proofing etc.). Allowing time for building material in new areas to off-gas pollutants before occupancy and smoking restrictions are some measures that can be used.
- AIR CLEANING can be performed by ensuring uncongested interiors with open office designs, use of frosted glass and skylights that give access to natural light, terrace gardens, community spaces and indoor plants that absorb carbon monoxide and formaldehyde from the air.
- BANNING OF SMOKING in the workplace or restricting smoking to designated well-ventilated areas away from the work stations and creating no-smoking zones.[2]
Remember:
- USE NATURAL VENTILATION
If it’s safe to do so (for example, no presence of young children and pets, risk of falling, triggering asthma symptoms, high levels of outdoor pollution), open doors and windows as much as you can to bring in fresh, outdoor air. You can open multiple doors and windows to allow more fresh air to move inside.
Most studies indicate that relative to natural ventilation, air conditioning, with or without humidification, was consistently associated with a statistically significant increase in the prevalence of one or more sick building syndrome symptoms, by approximately 30 to 200%2
- ALERGIC TO DUST MITES? Relative humidity greater than approximately 50% increases indoor dust mite levels. Low ventilation rates may thus increase the prevalence or intensity of allergic and other symptoms[3]
[1] United States Air and Radiation (6609J) Research and Development, Environmental Protection (MD-56) Agency https://www.epa.gov/sites/default/files/2014-08/documents/sick_building_factsheet.pdf
[2] Sumedha M. Joshi: The sick building syndrome, 2008 Aug, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2796751/
[3] Flannigan B, Morey P. Control of moisture problems affecting biological indoor air quality. ISIAQ guideline. Ottawa: International Society of Indoor Air and Climate; 1996. [Reference list]