Before anyone jumps on me The above subject header is from a study done in Germany. If true, it is good to know. Although I always take a single study with a pinch of study. In fact as a researcher I take a series of findings with a pinch of salt.
I don't have a copy of the full article, but here are is the authors and abstract.
Author(s): Wenzel M; Klauke M; Gessenhardt F; Dellweg D; Haidl P; Schönhofer B; Köhler D
Author's Address: Annostr. 1, Krankenhaus Kloster Grafschaft, Zentrum für Pneumologie, Beatmungs- und Schlafmedizin, D-57392 Schmallenberg, Germany.
Source: Chest [Chest] 2005 Oct; Vol. 128 (4), pp. 2138-40.
Publication Type: Journal Article
Journal Information: Country of Publication: United States NLM ID: 0231335 Publication Model: Print Cited Medium: Print ISSN: 0012-3692 (Print) NLM ISO Abbreviation: Chest Subsets: Core Clinical (AIM); MEDLINE
MeSH Terms: Continuous Positive Airway Pressure/*methods
Sleep Apnea Syndromes/*therapy
Aerosols; Humans; Sterilization
Abstract: OBJECTIVE: We investigated the necessity of using sterile water in humidifiers for avoiding respiratory tract infections during nasal continuous positive airway pressure (nCPAP) therapy. METHODS: Water in a convection-type humidifier (Sirius; Heinen and Löwenstein GmbH; Bad Ems, Germany) was labeled with (99m)Tc-diethylenetriamine penta-acetic acid. Low-flow (2 L/min, 4 L/min, or 6 L/min) and high-flow (31 to 46 L/min) rates were applied, rates typical for nCPAP. Heat and moisture exchange filters were placed behind the start of the tube to measure any radioactive aerosol. RESULTS: We demonstrated that no radioactive aerosols were produced, either with low or high flows. CONCLUSIONS: The convection-type humidifier produces water vapor but does not aerosolize the water. We conclude that bacteria, other microorganisms, or even solutes that may be contained in the water cannot be transported into the air and thus will not be deposited in the lung. In order to avoid respiratory tract infections, sterile water is not required, at least in this particular humidifier. We suggest that nonsterile tap water is probably a safe alternative.