[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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