Tours de refroidissement, eau vésiculaire et légionellose.

Cooling towers, drift, and legionellosis.

Auteurs : BUGLER T., LANE J., FIELDS B., et al.

Type d'article : Article, Synthèse

Résumé

This paper describes details about one of the important factors, cooling tower air emissions, by providing a comprehensive technical understanding of drift quantity, droplet distribution, and plume dispersion. By understanding these air emission details, ranges of Legionella bacteria concentration at distances from the tower can be estimated as a function of legionellae concentration in the tower water. It also describes the ecology of the bacteria in cooling towers and the epidemiology of outbreaks attributed to cooling towers. Most importantly, the paper discusses the correlation of the bacteria-exposure model described in this paper with the incidents of disease from previously studied outbreaks. The quantity of bacteria required to cause disease depends on several factors including the health of the individual and the exposure. A hypothetical example would be a situation where an individual could inhale 1 bacterium a week for fifty weeks with no ill effects, but develops disease when he inhales 50 bacteria in an hour. There is likely some exposure rate (inhalation of X bacteria/time) where the risk of disease may occur; the higher the exposure rate, the more likely the occurrence of disease. The inhalation rate (inhalation is the only means of transmission from cooling towers) depends strongly on two factors: 1) the concentration of bacteria in the ambient air in a particular area; and 2) the time spent in that area. This paper was originally presented at the 2008 International Water Conference, October 26-30, 2008 in San Antonio, TX, USA.

Détails

  • Titre original : Cooling towers, drift, and legionellosis.
  • Identifiant de la fiche : 2010-1444
  • Langues : Anglais
  • Source : CTI J. - vol. 31 - n. 1
  • Date d'édition : 2010

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