CAW National Council 4000
Occupational Health and Safety

Hazardous Substances:  Sick Building Syndrome

A certain pattern of health problems affecting more that 20 percent of workers and lasting for more than a couple of weeks
indicates Sick Building Syndrome (SBS). Some refer to it as: “tight building syndrome”, “office workers syndrome”; “building illness”;
or “building-related illness”.

Scientists associate about 50 different symptoms with SBS. Of these, the most commonly reported health symptoms are:

  • headache;
  • lethargy (fatigue), drowsiness;
  • eye irritation, throat irritation;
  • runny, plugged or bleeding nose;
  • sinus congestion;
  • skin irritation, dermatitis;
  • nausea;
  • dizziness, inability to concentrate;
  • upper respiratory problems, wheezing and/or coughing
  • chest tightness;
  • allergic asthma;
  • susceptibility to cold and flu-type disorders;
  • specific diseases like Legionnaires’ disease, hypersensitivity pneumonitis and humidifier fever.

Pollutants build up because the reduction of the amount of outdoor air in buildings is part of an overall energy conservation
program. It means shutting down or reducing the operating time of heating ventilation and air conditioning (HVAC) systems on
weekends and evenings. These measures dramatically increase the airborne pollutants indoors.

Possible Causes?

Modern sealed buildings use mechanical HVAC systems to supply air to occupants. Workers in these buildings are as dependent on
the HVAC system for air as they would be in a submarine or space capsule. Unlike those environments, the air in buildings does not
get scrubbed and purified. When pollutants build up in these closed environments the HVAC system spreads them throughout the
building. As a result, airborne pollutants mount in numbers and concentration causing and adding to health problems among

Investigators show that these systems also harbour, grow and spread bacteria, fungi and viruses. For example, the 1976 outbreak
of Legionnaires’ disease at a Philadelphia hotel was due to bacterial contamination of the HVAC system’s cooling tower. Twenty-
nine people died. Outbreaks of Legionnaires’ disease in buildings is a growing concern. It is now a recognized disease and the
government keeps records of outbreak and cases.

Source:  CAW Health, Safety & Environment Department