Document: NUREG-1555
Document ID: ccbea725-7fae-4453-bfec-b565c95a8e44
Document Type: esrp
Title: IMPACTS TO MEMBERS OF THE PUBLIC
Source: NUREG-1555
Source URL: https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1555/initial/
Revision Date: 2007-10
Chapter: 5
Section ID: 5.3.4
CFR Part: 
CFR Title: 

Content:
y found in natural surface waters, and thus it is not surprising that they are found in even greater numbers in water from cooling towers and evaporative condensers. This type of equipment can amplify Legionella sp. concentrations and disperse the pathogen through aerosolization (NRC 1996). Naegleria fowleri causes primary amoebic meningoencephalitis (PAM) and Acanthamoebic keratitis and Acanthamoebic uveitis cause granulomatious amoebic encephalitis (GAE). GAE is a particular risk for persons who are immunodeficient, although infections have occurred in otherwise healthy individuals (FDA 1996). The primary infection site is thought to be the lungs. The organisms that are in the brain are generally associated with blood vessels, suggesting vascular dissemination (FDA 1996). Only 100 to 200 reports of PAM have occurred worldwide (NRC 1996). Sources of infection for PAM generally include heated swimming pools, thermal springs, and a variety of naturally or artificially heated surface waters. During 1993 to 1994, only one case of PAM was reported by the Centers for Disease Control (CDC 1996). The one case was caused by N. fowleri and was associated with swimming in both a waste- water holding pond and in the Rio Grande River. A study of cooling waters from 11 nuclear-power plants and associated control source waters indicated that only two sites were positive for the pathogenic Naegleria fowleri. In addition to testing for pathogenic amoebae in cooling waters, the 11 nuclear-power plants in the 1981 study were also studied for the presence of Legionella sp. In general, the artificially heated waters showed only a slight increase (i.e., < 10-fold) in concentrations of Legionella sp. relative to source water. In a few cases, source waters had higher levels than did heated waters. Infectious Legionella sp. were found in 7 of 11 test waters and 5 of 11 source waters (NRC 1996). October 1999 5.3.4-9 NUREG-1555 An additional study of Legionella sp. presence in the environs