Using a dehumidifier to sample for legionella.

[Guest guest]

A question to all group members. Is it possible to use a dehumidifier to sample for legionella spp. within a shopping area open to public use. There is no or very little access to the unit. It is not possible to use swabs or collect the condensate water when possible. Sample impaction plates are also not used as I cannot verify this methodology. A possible sampling method may be to let the system work and the dehumidifier allowed to collect water from the air within the shop. As a result the condensate may be delivered to the laboratory for testing.Of course the unit has to be cleaned before perhaps with a UVC light or ozone as to minimize cross contamination from another site! Any thoughts ?????? Gerard Análises do Ar Ambiente Lda, Urb. Quinta Verde, Lote 842710-445 SINTRAPORTUGAL www.aaalda.com

[Guest guest]

Gerard,

My understanding is that Legionella spp. are ubiquitous. The concern is amplification in a reservoir that can then become aerosolized. Focus should be on potential reservoirs rather than air.

That said, with high enough air sample volume, I think you might be able to get some interesting data with QPCR analysis. Or, maybe you could collect surface dust and analyze via QPCR for "historical" airborne presence.

I don't think trying to culture legionella on the coils or in the reservoir of a dehumidifier is a good idea. It will not give you any reliable info.

Steve Temes

Using a dehumidifier to sample for legionella.

A question to all group members.

Is it possible to use a dehumidifier to sample for legionella spp. within a shopping area open to public use.

There is no or very little access to the unit. It is not possible to use swabs or collect the condensate water when possible. Sample impaction plates are also not used as I cannot verify this methodology.

A possible sampling method may be to let the system work and the dehumidifier allowed to collect water from the air within the shop. As a result the condensate may be delivered to the laboratory for testing.

Of course the unit has to be cleaned before perhaps with a UVC light or ozone as to minimize cross contamination from another site!

Any thoughts ??????

Gerard

Análises do Ar Ambiente Lda,

Urb. Quinta Verde, Lote 84

2710-445 SINTRA

PORTUGAL

www.aaalda.com

[Guest guest]

Consider looking at http://www.cdc.gov/legionella/files/LegionellaProcedures-508.pdf  Moffett From: iequality [mailto:iequality ] On Behalf Of Steve TemesSent: Thursday, May 10, 2012 1:20 PMTo: iequality Subject: Re: Using a dehumidifier to sample for legionella. Gerard, My understanding is that Legionella spp. are ubiquitous. The concern is amplification in a reservoir that can then become aerosolized. Focus should be on potential reservoirs rather than air. That said, with high enough air sample volume, I think you might be able to get some interesting data with QPCR analysis. Or, maybe you could collect surface dust and analyze via QPCR for " historical " airborne presence. I don't think trying to culture legionella on the coils or in the reservoir of a dehumidifier is a good idea. It will not give you any reliable info.Steve Temes Using a dehumidifier to sample for legionella. A question to all group members. Is it possible to use a dehumidifier to sample for legionella spp. within a shopping area open to public use. There is no or very little access to the unit. It is not possible to use swabs or collect the condensate water when possible. Sample impaction plates are also not used as I cannot verify this methodology. A possible sampling method may be to let the system work and the dehumidifier allowed to collect water from the air within the shop. As a result the condensate may be delivered to the laboratory for testing.Of course the unit has to be cleaned before perhaps with a UVC light or ozone as to minimize cross contamination from another site! Any thoughts ?????? Gerard Análises do Ar Ambiente Lda, Urb. Quinta Verde, Lote 842710-445 SINTRAPORTUGAL www.aaalda.com