Apparently the CDC hasn't read Pool School

[bolleat]

http://www.cdc.gov/mmwr/preview/mmwrhtm ... mm6219a3_x

First of all, detecting nucleic acid from a bacteria is not the same as finding a live bacteria in the pool. So their conclusions are faulty.

Secondly they give poor advice for pools, using test strips and chlorine levels that are too low/don't consider FC or CYA.

Embarassing article by the US government.

Oh and yes I am a scientist.

 

[chem geek]

See the thread BBB pools and sanitary conditions - CDC comment (my post is near the end of that thread). I totally agree with you about the inappropriate use of PCR and even wrote to the corresponding contributor about it, and though I got a response, I didn't get specific answers to some of my questions so I'll talk to her at the upcoming World Aquatic Health Conference (WAHC) later this year. Basically, they were just looking for any evidence of fecal contamination.

They write in their article that they aren't testing for live bacteria and they don't claim to predict anything about whether the water is sanitary. They are basically just saying that there is fecal matter being introduced into pool water. I believe they want to educate the public to take more care in showering/rinsing/cleaning before entering a pool and to not go in a pool if one has diarrhea, but scaring them into thinking that public pools are cesspools of fecal matter isn't the best way, in my opinion.

As for FC and CYA, I've written to the CDC about this relationship since at least 2006 and it's been a slow slog with only marginal progress. The CDC proposed Model Aquatic Health Code (MAHC) bans CYA from indoor pools and high-risk venues and I told them that was going too far. Limiting CYA to a low level is one thing and requiring a minimum FC/CYA ratio for such venues is also reasonable, but a ban is too restrictive and completely inconsistent by orders of magnitude between indoor and outdoor pools in terms of the active chlorine level.

Out of curiosity, what kind of scientist?

 

[bolleat]

I am actually an infectious disease physician and virologist/microbiologist. I have a masters degree in microbiology along with my MD and I work in the influenza research field.

 

[chem geek]

Outstanding! Well, if I write anything that's out-of-whack or I make any sort of mistake, I hope you'll correct it. My schooling emphasis was more in physics and chemistry (though my profession has been in S/W engineering) so the microbiology is "bits-and-pieces" learning for me.