Unexpected Radioactivity at Munich Airport - Lutetium 177?

[Go-Figure]

Hi there,
This is the last thread from my recent trip to Japan.
Actually, this post wasn’t supposed to exist at all.
When I landed at München (Munich) I thought I was done as far as radioactivity measurement was concerned for the day, but it turned out I was wrong.

I went through all the security checks and then headed towards the gate to take my last flight (to Florence).
Both my spectrometer and dosimeter were inside my bum bag. As you know, during security checks you have to place your belongings into plastic bags only taking them back after they have been scanned.
Nothing strange there.
I arrived at the gate less than an hour before boarding time and since I had time I decided to download the data I collected from my dosimeter and spectrometer while in flight in my PC.
As I took the dosimeter out I noticed a strange thing….the peak rate was supposed to be 10.60 µSv/h I recorded during the flight, but it was 1.87 mSv/h instead.
I wrote 1.87 mSv/h, millisievert/h, not microsievert/h, that was eye-popping!

I checked the graph and I saw the peak dose occurred at 4:54 PM, which was the time I was going through the security check. It must have happened while my belongings were scanned and it must have lasted just a little more than a second, because the average dose during that minute was 42.8 µSv/h. Here are both graphs.

01 - Munich Airport - Security Check - Peak Dose - 14-11-19.png

02 - Munich Airport - Security Check - Average Dose - 14-11-19.png

I was still checking the data while the PDS 100G (still inside the bum bag) started to vibrate, so I took it out and I saw it was reading more than 1µSv/h. The doserate decreased almost immediately but stayed well above what you would expect, between 0.60 and 0.90 µSv/h. What the hell was that now?

I immediately started to record a spectrum, looking around to try to find out what the source was.
It didn’t take me much to realise the source was a person just 2-3 meters away from me. A middle aged man, clearly not in great health, in a wheelchair pushed by two woman who were accompanying him. Him passing by had triggered the spectrometer. Getting closer to him made the doserate go higher, and getting farther from him produced the opposite effect, so there was no doubt it was him. Obviously he went through some sort of medical treatment and still had some radioactive material inside him.

I kept on accumulating data for 1500 seconds. I don’t know the name of the man, I can’t recall his face (I barely looked him in the face), I couldn’t recognise him if I saw him again, I basically have no idea who I am talking about, so I would say this is not violating anyone’s privacy. It could be anyone really.

I stopped recording the spectrum a minute before boarding, which was when I recorder the peak dose (graph below) as he passed by me at a distance of 30-40 cm.

Here’s the spectrum data. The dosimeter was still reading more than 2 µSv/h when I took the shot.

03 - Data - DSC03698R.jpg

And here is the average dose graph minute by minute.

04 - Munich Airport - Gate 33 - Average Dose - 14-11-19.png

As soon as I landed and I got in the train from Florence to my hometown I downloaded the spectrum to try to understand what I recorded.
Here’s the spectrum, both in LOG and LIN view.

05 - Munich Airpost Gate G33- 1500 Secs - 14-11-19 - LOG.png

06 - Munich Airpost Gate G33- 1500 Secs - 14-11-19 - LIN.png

So the question was: what is this? I have never seen a spectrum like this one before, so I went through the most common radionuclides used in medicine.
Tc99m, no.
I131, no.
I125, no.
Sr89, no.
Y90, no.
….plus another dozen or so of failed attempts…

I am still not sure what I am looking at here but my best candidate so far is Lutetium 177 (Lu177).
Here are two gamma Lu177 spectra, apparently both taken with an HPGE detector.

07 - g-ray-spectrum-of-177-Lu.png

[broken link removed - Steven]

08 - Fig-6-Gamma-spectrum-of-177-Lu-obtained-after-separation-from-Yb.png

[broken link removed - Steven]

Here are the nuclear data of Lu177
http://nucleardata.nuclear.lu.se/toi/nu ... iZA=710177

Peaks are at:
1 - 71.65 keV
2 - 112.95 keV
3 - 208.37 keV
4 – 249.67 keV
5 – 321.32 keV

And they are compatible with my spectrum, actually I can’t see the 249.67 keV peak (maybe buried in the slope) but I have peaks very very close to the other four.
I am not sure yet but maybe I solved the mystery spectrum.
Of course if anyone has a better candidate any suggestion is welcome!

And that’s the story of my short but pretty eventful stay at Munich airport!

Massimo

[Taray]

I deleted my first post here.
My impression is this gentleman has got advance prostate cancer and is wheel-chair bound due to bone secondaries in his pelvis.
He is on therapy with a radio oncologist perhaps with Lu177 .This is based on my reading and medical experience.
Well I could be wrong but I like to make up a plausible explanation
Taray

[sgt_bear]

Yes Taray's answer is very likely.

Any university hospital of munich does such a therapy
http://www.klinikum.uni-muenchen.de/Kli ... index.html

As the page writes, this form of threathment is sort of "individual and only used at persons that cant be healed by other means".

[Go-Figure]

Yeah,
When Lu177 became my best candidate I googled "Lutetium 177 Munich" and I found:

[broken link removed - Steven]

http://www.klinikum.uni-muenchen.de/Kli ... index.html

[broken link removed - Steven]

That was an indication that the Lu177 hypothesis was compatible with Munich.

Massimo

[Go-Figure]

Hi folks.
There's still a question mark for me here, but since so far I have found no valid alternatives, I labelled the peaks.
I didn't put any photo or even the name of the airport in the spectrum picture, because when you post something online you never know where it might end up being shared and I don't want someone to use this for whatever reason to associate that particular airport to this spectrum. Clearly the place has nothing to with it.

Massimo