Friday, September 23, 2011

Crosspost from A very misleading “bacteria in buildings” advertisement presented as “news”

Am crossposting this from where I posted it earlier. See original post here: A very misleading “bacteria in buildings” advertisement presented as “news”
Wow this “story” (which is really an ad) is just so incredibly bad I do not know what to say: Dangerous Bacteria Isolated in Healthcare HVAC Evaporator Coils. I do not even know where to begin with criticism so I will just go step by step through some of the advertisement.
1. Title: Dangerous Bacteria Isolated in Healthcare HVAC Evaporator Coils
There is no evidence that the bacteria being looked at here are dangerous.
2. First sentence ”A recent study suggests that doctors may want to monitor the environmental condition of their air conditioners evaporator coil before surgery to help prevent the spread of bacterial infections”
No evidence is presented anywhere that monitoring AC coils has any even remote potential value here.
3. Second sentence: Dr. Rajiv Sahay, Laboratory Director at Environmental Diagnostics Laboratory (EDLab) and his colleagues sampled evaporator coils in healthcare air handling systems and isolated Pseudomonas aeruginosa a known noscocomial pathogen.
Well, Pseudomonas aeruginosa is indeed a known pathogen.  However, there is no evidence presented that all the things they detect are indeed pathogenic/virulent.  In fact, later in the article they report their results as being for “Pseudomonas sp” which suggests that their typing was very broad.  It is very possible that many of the cells they detected are not pathogenic.
4. Ignore the middle part.  It is just saying that Pseudomonas aeruginosa can be nasty in compromised patients.
5. They then go on to discuss their study more “In the study, over 560,000 colony forming units (CFU)/gram of Pseudomonas sp were isolated from deep within the evaporator coil system.”
What study?  No data is presented.  No methods.  No results.  Nothing.
6. They then say “Potential aerosolization of these micro-organisms from the infested coil is immense due to a discharge of air stream with 6 miles/hours (commonly observed) across the evaporator coils”
Not so sure about that.  Would have been much better to study ACTUAL aerosolization.
7. Then we find out that they person who conducted the study Dr. Rajiv Sahay is also the one selling the cleaning service to clean your air coils.  That does not instill confidence in me.
So a person selling HVAC cleaning reports unpublished results that they claim suggest if you do not clean your HVACs in hospitals you put all your patients at risk.  I am on board with the need to study microbes in hospitals more.  I am on board with the potential risks of microbes in AC systems.  I am not on board with not presenting data, and with getting the science wrong.

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