UV water treatment and endotoxins

[Rob Rob]

I purchased a Steripen handheld UV water purifier. It uses UV light to treat water that may be contaminated. The claim is that the UV radiation damages the microorganism in a way that prevents reproduction, and that microbes that can't reproduce can't make you sick. 

But from my memory of Microbiology class many years ago, I recall that some bacteria release endotoxins that cause illness.

So I'm thinking that even if I used this device on a glass of lake water that had a significant amount of bacteria, they still might dump endotoxins into my system if the cells are lysed in my stomach acid.

Any thoughts on this?

Thanks!

[CharonY]

You are not wrong and it depends on the water source. UV serves a similar purpose as chlorination. However, if the water is already  highly contaminated it may still be unsafe (including e.g. neurotoxins from algae blooms).

[StringJunky]

I looked into this, then forgot about it. You need something like a microporous polyethylene membrane to filter it out.

[John Cuthber]

In principle, enough UV of short enough wavelength will destroy almost  any organic molecules in the water.

You are not going to achieve that with anything you can carry in a pocket.

[PhilGeis]

We're constantly exposed to endotoxin -  including drinking water and via normal gut and oral flora.    High levels in drinking water have been associated with cyanobacterial blooms. Hemodialysis and respiratory exposure to endotoxin-laden water has been associated with some symptoms - not drinking the water.  I'd not be worried about the water mentioned above and wouldn't put too much faith in the device.   UV doesn;t penetrate water that well and even less in water with suspended particulates.  Also be aware that microorganisms use both light and dark repair mechanisms to repairr UV damage.