[Greenbuilding] Flatten the Curve

Corwyn corwyn at midcoast.com
Sun Aug 21 09:59:20 CDT 2011


On 8/20/2011 9:53 PM, Paul Eldridge wrote:
> Hi Corwyn,
>
> As noted at the bottom of the Hydro-Québec page: "This message was
> prepared by the Hydro-Québec Direction – Santé et sécurité in
> conjunction with the Ministère de la Santé et des Services sociaux du
> Québec."
>
> I have no reason to doubt its validity. Do you?

I have learned to be leery of any company admonishing me to buy more of 
their product in order to be safe.

I am no expert on Legionella, though the subject comes up frequently here.

The CDC says (in http://www.cdc.gov/ncidod/eid/vol10no3/02-0707.htm ) 
"...an operating temperature >50°C was predictive of noncontaminated 
samples (OR 0.25; 95% CI 0.11 to 0.98, p < 0.05)."

"The percentage distribution of Legionella species differed 
significantly according to the heater system (chi-square = 14.00, p < 
0.05). Electric heaters were legionellae-free; the gas-heated 
independent systems had little contamination (10.0% of those with tank 
and 16.4% of those without) and were mainly colonized by either L. 
pneumophila serogroup 1 or non-pneumophila Legionella species. In the 
centralized heating systems of both single buildings and neighborhoods, 
Legionella colonization was higher (52.8% and 66.7%, respectively), and 
L. pneumophila serogroups 2–14 were the most frequently isolated serotypes."

"To limit Legionella colonization at the domestic level, we suggest 
simple and general measures: 1) use independent domestic water heaters, 
2) maintain high cleaning standards, 3) periodically replace components 
of the system which could favor presence or dissemination of bacteria, 
and 4) have a water copper content >50 µg/L. We do not believe 
disinfecting measures at the domestic level are needed, considering that 
our retrospective study on pneumonia in residents did not show a 
relevant evidence of risk in colonized buildings."


Thank You Kindly,

Corwyn

-- 
Topher Belknap
Green Fret Consulting
Kermit didn't know the half of it...
http://www.greenfret.com/
topher at greenfret.com
(207) 882-7652




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