“Las Vegas pool enthusiast” twitter is pushing back on this. I’ll explain what I know. https://twitter.com/dankaszeta/status/1264657138963668992

Random Las Vegas guy takes umbrage at my trustworthiness, not knowing who I am or the broad outlines of my career.

So, let me explain. Time for Captain Dan to tell a story.

Oh no. Another person tells me I can't tell this story. Obviously that will stop me.

Many of you are familiar with the broad outlines of my career. Many of you are not. I encourage those of you not familiar with my career to brush up on it.

The broad outlines of my career in chemical, biological, and radiological stuff are outlined in this thread. https://twitter.com/DanKaszeta/status/982642721495113728?s=20

Anyway, the late 1990s were an interesting time in the Federal government. The govt was just starting to take CBRN terrorism, anthrax, all that stuff seriously.

I was the chemical and biological terrorism guy at the White House Military Office and one of a relatively few people in a good position to advocate stuff at the working level as opposed to the top-down policy level

Washington DC had had its first major bioterror scare at the B'Nai Brth building but the full weight and organization of the US government was only slowly churning to build effective response to possible chem/bio terrorism

As part of a pro-bono effort to help other government agencies prepare along these lines, I gave seats in my training courses that would otherwise go unfilled to people from other agencies.

I ran a highly regarded (and, for a while at least, academically accredited) 2 week CBRN training course for the White House Military Office

Eventually, due to my contacts and alumni from my course, I had a reasonable network of people in various departments and agencies across the US govt gradually building capability and capacity on chem and bio terrorism.

So, one day, I got a phone call at the White House. I can't remember if it was '98 or '99. One of these guys, from another Federal agency needed help and advice from me. Obviously the exact words are lost to me but it went something like this

"Dan, ya gotta help me. I'm working this case in Vegas. It's probably nothing but it could be a bio thing. But I need access to a lab that can keep this on the downlow until we know what the deal is."

I had a rolodex (look it up young folk) full of esteemed scientists at the US government's finest labs. I made a few calls and sorted out a process for this guy in the field to submit some samples for a full chemical and biological analysis. The lab guys looked forward to it

Part of the forensic integrity of such a process is the inclusion of blanks as control samples. Such as empty bags and tubes that weren't used, samples of background material, and such.

In this case, I seem to recall the suspect item was a clear liquid. The guy in the field collected some control and background samples. Including tap water and some swimming pool water. From a major hotel.

You can see where this is going.

Two days later, I get a phone call in the middle of the night at home. From the White House switchboard. The lab is VERY eager to talk to me

Now, the lab, wisely and in accordance with good processes, did not know which sample was which. It turns out the "suspicious" liquid that had kicked off the investigation was something relatively harmless like glycerine.

The sample that had one of the finest labs in the country alarmed so much was, erm, the control sample from the pool water.

It was, to use a technical phrase "a shop of horrors"

So, I asked the good scientists what was in this sample. They said it was easier to say what WASN'T in the sample.

Alarming levels of Giardia and Cryptosporidium, both highly resistant to chlorine. A huge number of metabolites from human urine. Fecal matter, human, mammal, and avian. Trace amounts of cocaine, ketamine, and several different opiates.

Adenoviruses. A weak immunochromatographic hit for Tularemia (not conclusive). Campylobacter.

A soup of other things that I didn't even know existed. There I was at 3 am reading my manuals.

Now, a study like this isn't revelatory if it isn't reproducible. For giggles, I called my guy and told him to collect some more pool samples from other pools. You can guess how that worked out.

I went and got Potomac river water and sent it in. It was safer.

A few years later, I was in Las Vegas. I collected a sample and brought it back. By this point, I was working for the US Secret Service, but I still had my contacts with the labs. (Indeed, lab liaison was part of my job). Well... same shit, different year.

Long story made short - chlorination kills some things, but not others. "Las Vegas pools are clean and safe" is not the hill I'd choose to die on.

Have a nice day.

There's academic literature on this sort of thing. For example Int J Environ Res Public Health. 2019 Jan; 16(2): 166.
Published online 2019 Jan 9. doi: 10.3390/ijerph16020166

Honestly, I don't care if I make Las Vegas upset with this thread. I know what I know. Do what you want. Personally, I'd avoid a Vegas pool.

What happens in Vegas... stays in the pool water.

I did warn you all. Sometimes I know things that others do not know.

PS. Chlorination and overchlorination can lead to other problems as well. See: https://doi.org/10.1016/j.ijheh.2011.07.012

Have a nice day. Stay safe.

PS - People have asked about sunlight, thinking somehow this makes things safer. Actually, in a lot of ways it makes it worse because it reduces the available chlorine in the water. https://sciencing.com/heat-sun-affect-pool-chlorine-21723.html

Another thing was asked - so, why aren't thousands of people sick? Well, who says they aren't. There's no reporting mechanism that's going to pick up most of these illnesses. And the victims will likely get sick a few days after exposure, so many/most will already be back home