Lesson 2 Biological factors

  • Exposure to biological risk factors refers to biological hazard (often related to as biohazard). In common perception it seems to be the most well recognized category of risk factors, often emphasized by various movies or novels.
  • However it is necessary to emphasize that although fictional stories are designed to provide entertainment, there is a serious and real danger related to this kind of risk factors.
  • A biological hazard is a biological substance which creates threat for health of living organism.
  • This biological substance may be microorganism (bateria, parasites, moulds or fungi), virus or toxin.
  • They can be inhaled, eaten or come in contact with skin.

Fig. 2. Biohazard sign (different designs)
Source: Public domain

  • It can be found on containers with dangerous biological materials, such as virus samples or medical waste (e.g. used syringes or hypodermic needles).
  • In your work as a cleaner you may encounter containers or bags with such label, which should alert your caution and should be processed with special care and keeping up to the standards.
  • However there are biological risk factors that you may be exposed to without knowing it.
  • Among cleaners exposure to fungi has been recognized, which may cause hypersensitivity reactions due to fungal antigens inhaled with dusts, which usually involve pneumonitis with asthmatic symptoms.
  • Another example is an exposure to mould which may be connected to allergic skin conditions. This may occur during e.g. emptying dust collectors).
  • You may also be exposed to biological risk factors through a contact with rodent droppings or different vermin that may carry diseases.
  • Drivers of waste collecting trucks may be at risk of exposure to hazardous cargo.
  • infectious agents (bacteria, viruses, protozoa, helminths, and fungi) present in the raw domestic wastewater (mainly from human origin) and in agricultural wastes
  • contact with the toxins released by the infectious agents
  • insects or rodents proliferating in the sludge drying beds.

Fig. 3. Examples of biological risk factors and their potential implications
Sources: Virus – Public domain, graphics by CDC/ Alissa Eckert, MSMI; Dan Higgins, MAMS;
Bacteria – Public domain, graphics by CDC/ Evangeline Sowers, Janice Haney
Carr; Fungi – Public domain, graphics by CDC/ Dr. Hilliard F. Hardin