Management and Prevention of Infectious Diseases on Construction Sites

(For NCA only and optional for other regions)

The Real Property Branch (RPB) has implemented preventative and control measures to protect individuals, assets and construction sites against the risks associated with pigeon and bat droppings. Public Services and Procurement Canada (PSPC) building, bridge, dam and wharf structures provide natural nesting habitats for pigeons and bats. This, in turn, exposes PSPC employees, clients, consultants and contractors to higher levels of health risks associated with the inhalation of airborne particles from the resultant droppings.

Human exposure to pigeon or bat droppings can result in infections, disease, flu/pneumonia-like symptoms, blindness, and in rare cases, death. The two primary diseases resulting from the inhalation of these droppings are 'hypersensitivity pneumonitis' and 'histoplasmosis'. Another rare but related fatal disease is 'disseminated histoplasmosis'.

  • Hypersensitivity Pneumonitis: An allergic type of lung disease related to the inhalation of protein material within pigeon and bat droppings. Usually, there are flu-like symptoms such as: chills, fever, fatigue, cough, and shortness of breath, which generally occur between 5-10 hours after exposure.
  • Histoplasmosis: An infectious disease caused by the inhalation or ingestion of the spores of a fungus called 'Histoplasma Capsulatum', or the contamination of bodily fluids by the spores through other means. The spores are usually found in areas inhabited by pigeons and/or bat colonies. This condition can be mild to very severe with pneumonia-like symptoms usually appearing within 3 - 18 days after exposure.
  • Disseminated histoplasmosis is the rarest, most severe form, and involves the spreading of the fungus to other organs outside of the lungs. This form is fatal if not medically treated, and in some cases is fatal even with medical treatment. Histoplasmosis cannot be transmitted through person-to-person contact.

The Ministry of Labour advises that these droppings cannot be classified as a hazardous material since they are neither a manufactured nor a controlled product. They do, however closely match the materials classified in the Workplace Hazardous Materials Information SystemThis link is available only to clients with access to Publiservice, the Government of Canada extranet. Class D, Division 3, Biohazardous Infectious Material. Due to the nature of real property projects, project managers must:

  • be aware of the existence and dangers of histoplasmosis
  • be aware of environments which facilitate exposure to histoplasmosis
  • take the necessary steps to protect individuals, assets and construction sites against histoplasmosis by implementing the necessary prevention and control measures to help eliminate histoplasmosis at the source

Prevention and Control Measures


On projects with a probability of encountering histoplasmosis, project managers should:

  • be aware that the early fall season has the highest probability for histoplasmosis due to the fact that bats and birds are seeking shelter for the winter months
  • for specific cases, contact PSPC health and safety discipline staff and environmental services discipline staff early in the planning stage of the project for advice and expertise related to the building/asset and individual health issues
  • investigate the possibility of colonies of bats or birds roosting in a building/workplace
  • allow for related corrective measures within the specifications for the work prior to tendering
  • determine the building's/workplace air quality prior to construction activities through pre-construction assessments such as environmental air monitoring
  • take immediate action (when possible) to seal all entry points into the building/structure. This may be very difficult to achieve when a building/workplace is undergoing demolition work that creates openings within it, therefore this must be considered during the pre-planning stages of a project
  • ensure all contracts required for the work incorporate clauses which clearly stipulate requirements for a contractor to follow in the event of the discovery of histoplasmosis
  • once the construction contract is awarded, the contractor assumes control of the building/workplace/site and becomes legally liable through the contract for dealing with histoplasmosis contamination
  • other items to consider are:
    • posting of signs warning of potential health risks
    • emergency procedures/key contact person/phone/fax/cell/e-mail
    • informing workers, in writing, of the potential risk factors

Preparation Phase


  • inform workers of the risk of disease and the need for adhering to all preventative and control measures
  • recommend a specific medical assessment of workers for histoplasmosis prior to the start of the project. This may include chest x-rays, serologic (blood) tests, and skin tests. Also consider pulmonary function tests, fitness to wear a respirator, and immunization against tetanus.
  • ensure that hygiene facilities have been installed or are available (e.g. temporary showers)
  • ensure workers are aware of the symptoms of heat stress conditions and the importance of maintaining adequate fluid and salt intake when working in hot conditions. Recommend that arrangements for providing cool drinking fluids, in an uncontaminated area, should be made, especially replenishing fluids and electrolytes like Gatorade.

Work sites

  • carry out bacteriological testing of droppings before any cleanup is started. It is preferable to assume that the droppings are contaminated and to implement the cleanup appropriately. Spot tests resulting in a 'negative' result do not guarantee that 'all areas' are non-infected.
  • rope off suspected contaminated areas and post signs denoting the areas as 'hazardous', 'restricted', and/or 'no entry'.
  • when work involves removing potentially contaminated soil, implement chemical decontamination 2-3 days prior to actual removal, by soaking the soil to a depth of approximately 6 in./150 mm with a 3% formaldehyde solution or a 5.25% chlorine solution.

Waste Cleanup Phase


Should wear protective clothing available at the work site such as:

  • disposable hooded coveralls (ex. Tyvex suit) which are reasonably impervious to the contaminated material and can be changed as needed
  • gloves, preferably rubber since wetting procedures are used to suppress dust
  • rubber boots - since daily washing will be necessary to remove any debris
  • respirators with a good protection factor and the most efficient filter possible (a full- face National Institute of Occupational Safety and Health (USA)(NIOSH) approved respirator with HEPA filters is recommended). The respirator should be washed and decontaminated at the end of each shift as mucous membrane contact, especially in the eyes, can result in serious infections.

Work sites

institute and stress safe work practices:

  • where ventilation systems exist, shutdown ventilation system
  • seal intake and output duct openings to isolate areas where contaminated dust is produced
  • remove old, potentially contaminated filters, properly bag and send for waste disposal
  • where duct work exists, clean out debris
  • screen off any outside ventilation intake openings to prevent birds etc. from re-entering
  • keep droppings sufficiently wet (with water) to minimize the amount of dust becoming airborne. Where droppings are excessive, repeat wetting is necessary during cleanup. It is advisable to use a low pressure hose for spraying with water.
  • discourage walking near or in droppings and ensure that only 'wet down' droppings are scraped and shoveled
  • double bag and label dampened material as 'biohazardous water'. Consult with Ministry of Environment on methods of disposal.

Note: There are specified methods to dispose of contaminated material and the contractor must provide a certificate of proper disposal.

Post-Cleanup Phase


  • Individuals carrying out the aforementioned tasks must be provided with personal protective equipment. To avoid any health complaints before, during, or after the carrying out of the activity, workers should be made to wear protective coveralls, gloves and rubber boots. A half mask respirator with chlorine canisters should be used if ventilation is reasonable (i.e. windows, positive/negative pressure) If the area is confined and large amounts of chlorine solution are to be used, a full face air-supplied respirator should be used. For use of controlled products, obtain and refer to the appropriate Material Safety Data Sheet.

Work sites

  • Areas of work site contamination usually involve stone, old timbers and old concrete. These materials are porous, sometimes resulting in the possibility of the presence of some residual contaminated material remaining (this also applies to any fixtures i.e. lights). Therefore, if the structure is to remain as is or is part of a renovation, further decontamination should be considered. Spray, and thoroughly soak all contaminated areas and wash all fixtures with a hypochlorite solution (1:9 Javex/water).

For other sites such as bridges and on/around dams, no contaminated materials must be permitted to fall into or be disposed into the underlying or surrounding marine environment.