Hygiene Risks
4. Biological Pollutants
The name biological agents is given to all microscopic living beings of a diverse nature (bacteria, funguses, viruses, parasites) that may be present in certain workplaces and which are capable of producing adverse effects (infectious, toxic or allergic) for the health of workers.
The main legal regulations regarding the protection of workers against risks derived from biological agents at work is Spanish Royal Decree 664/1997. According to its stipulations, a catalogue of biological agents may be established into four groups on the basis of the risk of infection:
- Group 1: Biological agents that are unlikely to cause disease in humans.
- Group 2: Biological agents that are the cause of diseases (pathogens) and which may cause disease in humans under favourable circumstances, but which are unlikely to be propagated to the group, with effective treatment usually existing.
- Group 3: Pathogenic biological agents that can produce serious diseases in humans, with the risk of being propagated to the group, with effective treatment existing.
- Group 4: Pathogenic biological agents that can produce serious diseases in humans, with the risk of being propagated to the group, with no effective treatment existing.
The classification of biological agents is accordingly made on the basis of the parameters summarised in the following table:
| CHARACTERISTICS OF THE AGENT | RISK GROUP | |||
|---|---|---|---|---|
| 1 | 2 | 3 | 4 | |
| Likely to cause disease | NO | YES | YES | YES |
| The disease is easily propagated | NO | YES | YES | |
| An effective remedy exists | YES | YES | NO | |
The main biological agent that workers belonging to the ISASTUR Group may be exposed to is the bacterium Legionella pneumophila, the cause of the disease known as legionella o legionellosis.
4.1. Legionella pneumophila
According to the aforementioned criteria, the legionella bacterium would be a Class 2 biological agent capable of surviving in a broad spectrum of physico-chemical conditions at temperatures between 20-45º C. It proliferates in surface waters and may pass from there into the distribution networks of A/C systems with/without a return circuit, cisterns, or cooling systems that present inadequate maintenance, lack of such or deficient installation design.
4.2. Preventive measures to adopt:
- The corresponding planning of periodic revisions of installations at risk is to be established (A/C systems piping, cooling systems, etc), in compliance with the stipulations of Spanish Royal Decree 865/2003, which establishes the hygiene/healthcare criteria for preventing and controlling legionellosis.
Said maintenance revisions must be carried out by duly trained and qualified personnel or companies, paying special attention to the minimum characteristics that must be included in the maintenance programme for the installations. - In the case of reforming already existing installations, or developing new installations, special attention is to be paid to specific preventive measures for the installations, included in the regulations in force.
