Healthy Indoors Magazine - USA Edition

HI April 2014

Healthy Indoors Magazine

Issue link:

Contents of this Issue


Page 39 of 53

40 April 2013 of state and federal public health organizations. Unfortunately, the continuing rise in incidence rate of Legionnaires' disease and the fact that it constituted over half (58%) of all waterborne disease outbreaks, 42% of illnesses and 96% of hospitalizations in 2009-2010 suggests that current practices are not working.(5) Guidance on the prevention of LD in certain high-risk populations found in healthcare fa- cilities was published by the Centers for Dis- ease Control and Prevention (CDC) in 2003. (6,7) These recommended measures are more proactive than what is typically practiced in other public buildings. However, outbreaks and sporadic health care acquired cases of LD still occur. Implementing preventive measures and sampling protocols that are recommended for high-risk healthcare populations have not been recommended by the CDC for broader use in public buildings. Despite the recognition that hot water kept in storage tanks below 124 degrees F poses an increased risk of amplifying Legionella bacteria, the CDC guidelines continue to defer to local plumbing codes that prohibit hot water delivery above 120 degrees F. This conflict between scalding hazards and exposure to potentially lethal bacteria is readily managed with currently available technology, namely thermostatic mix- ing valves. Reconciliation of this conflict be- tween Legionella risk and scalding risk has not occurred at the local or national level. RESEARCH NEEDS FOR PREVENTION, TESTING, AND REMEDIATION The need for comprehensive research that fills the knowledge gaps on how to effectively prevent amplification of Legionella and to eco- nomically monitor these efforts are just two of the critical areas of research. A robust research program focusing on the currently available test methods and laboratory analysis of water samples so that Industrial Hygienists can ef- fectively interpret sample results and guide treatment regimens is desperately needed. Research on the next generation of faster and more robust testing methods is needed to lay the foundation for future investigators. Finally, a rigorous research program that monitors Legio- nella control effectiveness in a building water system after an amplification site has been identified is needed. Most of the guidance for remediation relies too heavily on trial and er- ror and what could be described as case series assessments. The adverse impacts of aggres- sively treating a potable water system or cool- ing tower with biocides, many of which can be corrosive, are not commonly weighed against their effectiveness. Research that helps to de- fine the secondary parameters and conditions that should be considered and controlled during remediation efforts could improve the success rate and reduce the retreatment often needed during remediation efforts. Without many of the research questions being answered, practitio- ners will need to continue to rely upon trial and error, professional judgment, and sometimes

Articles in this issue

Archives of this issue

view archives of Healthy Indoors Magazine - USA Edition - HI April 2014