UV Light Does Not Fully Purify Water

[enricosavazzi]

A reference about the (non-) sterilizing effects of UV:

 

http://www.the-scientist.com/?articles.view/articleNo/42009/title/UV-Light-Doesn-t-Fully-Purify/

[Andrea B.]

Thanks, Enrico. That was an interesting link.

[JCDowdy]

A couple of little problems with the paper. There is no description of UV intensity measurements. Also, it is not explicitly stated, that I could find in the article or supporting information, that the UV attenuating culture dish lid was actually removed during UV exposures.

 

We are left to assume an appropriately calibrated UV-C radiometer was used, you would be shocked to know how many otherwise diligent researchers neglect this non-trivial aspect. Here is a short quotation from the methods: "Trizol reagent (Invitrogen, Cat. No. 15596−026) was used to extract and purify total RNA from E. coli and P. aeruginosa according to the manufacturer’s instructions. Total RNA was quantified spectrophotometrically at an optical density of 260/280 (OD260/280) (AS-Nano100−1072; AOSHENG, Shanghai, China)."

 

These researchers reported the brand and catalog number of RNA extraction reagent as well as the city of manufacture of the spectrophotometer used to do a routine OD measurement but the can't properly characterize the UV dosimetry in a paper about efficacy of UV disinfection? I cannot understand how journal reviewers allowed such a glaring omission to be published.

 

Yes, this is a pet peeve of mine, but a valid objection nonetheless.

 

See:

Gasparro, Francis P., and Douglas B. Brown. "Photobiology 102: UV Sources and Dosimetry- the Proper Use and Measurement of''Photons as a Reagent''." Journal of Investigative Dermatology 114.4 (2000): 613-615.

[Andrea B.]

Eternal vigilance is also useful in Science. :D

 

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