Comparative assessment of chlorine, heat, ozone, and UV light for killing Legionella pneumophila within a model plumbing system

Journal Article · Sun Feb 01 04:00:00 EST 1987 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6516596

Muraca, P; Stout, J E; Yu, V L

Nosocomial Legionnaires disease can be acquired by exposure to the organism from the hospital water distribution system. As a result, many hospitals have instituted eradication procedures, including hypercholorination and thermal eradication. We compared the efficacy of ozonation, UV light, hyperchlorination, and heat eradication using a model plumbing system constructed of copper piping, brass spigots, Plexiglas reservoir, electric hot water tank, and a pump. Legionella pneumophila was added to the system at 10(7) CFU/ml. Each method was tested under three conditions; (i) nonturbid water at 25 degrees C, (ii) turbid water at 25 degrees C, and (iii) nonturbid water at 43 degrees C. UV light and heat killed L. pneumophila most rapidly and required minimal maintenance. Both UV light and heat (60 degrees C) produced a 5 log kill in less than 1 h. In contrast, both chlorine and ozone required 5 h of exposure to produce a 5 log decrease. Neither turbidity nor the higher temperature of 43 degrees C impaired the efficacy of any of the disinfectant methods. Surprisingly, higher temperature enhanced the disinfecting efficacy of chlorine. However, higher temperature accelerated the decomposition of the chlorine residual such that an additional 120% volume of chlorine was required. All four methods proved efficacious in eradicating L. pneumophila from a model plumbing system.

• Research Organization: Veterans Administration Medical Center, Pittsburgh, PA
• OSTI ID: 6516596
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 2; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

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560200 -- Thermal Effects
560300 -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BUILDINGS
CHLORINE
COMPARATIVE EVALUATIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY
ENERGY SYSTEMS
GEOTHERMAL SYSTEMS
HALOGENS
HEAT
HOSPITALS
HOT-WATER SYSTEMS
HYDROGEN COMPOUNDS
HYDROTHERMAL SYSTEMS
LEGIONELLA PNEUMOPHILA
MEDICAL ESTABLISHMENTS
MICROORGANISMS
NONMETALS
OXYGEN COMPOUNDS
OZONE
PLUMBING
RADIATION EFFECTS
RADIATIONS
SIMULATION
STERILIZATION
TEMPERATURE EFFECTS
TOXICITY
ULTRAVIOLET RADIATION
WATER