Effect of copper and silver ionization on Legionella pneumophila eradication

Book · Wed Nov 01 04:00:00 EST 1995

OSTI ID:116308

Lin, Y E; Vidic, R D ^[1]; Stout, J E; Yu, V L ^[2]

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1. Univ. of Pittsburgh, PA (United States)
2. VA Medical Center, Pittsburgh, PA (United States)

The presence of Legionella pneumophila in water distribution systems has been epidemiologically linked to hospital-acquired Legionnaires` disease. The objective of this study was to evaluate the efficiency of copper and silver ions for inactivation of Legionella pneumophila. Experimental results showed that L. pneumophila was completely inactivated at copper concentration of 0.1 mg/L within the period of 2.5 hours while 6-log reduction requires a Ct value of 0.8 mg/L*hour. On the other hand, more than 24 hours was required to completely eradicate L. pneumophila at the highest silver ion concentration (0.08 mg/L) tested and only 4-log reduction is observed for Ct value of 0.8 mg/L*hour. The effective synergism of these ions in eradicating L. pneumophila was observed for copper concentrations of 0.05 and silver concentration of 0.04 mg/L. One approach for the control of L. pneumophila in water distribution systems is to initiate copper/silver ion concentrations at 0.4/0.04 mg/L to achieve complete eradication of L. pneumophila already present in the water distribution system (as established in previous studies) followed by a lower residual (0.05/0.04 mg/L) protection against L. pneumophila in the incoming water.

• OSTI ID: 116308
• Report Number(s): CONF-9507173--; ISBN 0-7844-0095-4
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BACTERIAL DISEASES
COPPER
EXPERIMENTAL DATA
INFECTIOUS DISEASES
LEGIONELLA PNEUMOPHILA
SENSITIVITY
SILVER
TOXICITY