Unexpected Tc-99m detection on a coworker

Unexpected Tc-99m detection on a coworker

Hi,
I had an unexpected Radiacode detection today at work and thought it might be interesting for this community.

My Radiacode first started alarming while I was walking to the restroom. On my way back, I tried to locate the source and eventually found that the signal was coming from one of my coworkers.

He told me he had received some kind of medical “cocktail” for a nuclear medicine procedure / contrast-like examination. I measured up to around 4****k cps close to his chest pocket area.

I recorded a spectrum for about 6–7 minutes and attached the screenshot. The main peak appears to be around 140 keV, so my first guess is Tc-99m. There is also a visible feature around 88–90 keV, which I assume is probably backscatter from the 140 keV gamma line rather than a second isotope.

Additional context: he mentioned that the tracer was supposed to accumulate in organs, and he is scheduled for dialysis tomorrow. I am not asking for a medical diagnosis, just curious about the spectrum and isotope identification.

Does this look like a typical Tc-99m medical spectrum to you? And would you also interpret the ~90 keV peak as backscatter?

u/Petnek — 5 days ago
▲ 5 r/kia

Just joined the Kia family with a Ceed SW 1.5 T-GDi

Hi everyone,
I just bought my first Kia and wanted to share the excitement. It is a Kia Ceed SW 1.5 T-GDi TOP, manual transmission, in blue metallic, year 2022, 59 000 km.

I am coming from a 2003 Volvo S60 D5, which served me incredibly well and had over 500,000 km on the clock. It was a tough, comfortable and reliable car, so replacing it was not an easy decision. But after driving the Ceed, I feel like I made the right move.

The car feels much more modern, quiet and practical, while still keeping a very normal and honest driving feel. I like the size, the estate body, the equipment, the LED headlights, heated seats and steering wheel, and the 1.5 T-GDi seems like a very good match for the car.

It is still strange to leave the Volvo era behind, but I am genuinely excited about this new chapter with Kia.
Happy to join the community.

Any Ceed owners here with long-term experience or tips for a new owner?

u/Petnek — 11 days ago
▲ 199 r/gshock

GW-BX5600CBG-2ER joined my work rotation. This display is seriously impressive

Just picked up the GW-BX5600CBG-2ER and I’m honestly more impressed than I expected.

My plan is to wear it mainly at work, where I’m a test engineer in hydrogen technologies. My time is roughly split 50:50 between open office and lab work, so I wanted something tough, practical and still good looking enough for daily work use. Most of my work clothes are dark blue or navy, and this model fits that style almost perfectly.

At home I wear M5610U, which I still really like, but the display on the BX5600 is on another level. The viewing angles are dramatically better. I did not expect the difference to be this noticeable. I have just these two models, yet🤫🤭.

Curious what other square G-Shock fans think of this model. Underrated, or just a very specific taste?

u/Petnek — 21 days ago

RC 102 overheated

How it looks like when you forget RC 102 on the dashboard in partially (thank God) cloudy day? When I arrived after work, it shows 57 °C and really, really high readings. After cool down under 50 °C readings decreased to normal values.
It was in ankle strap.
After all this, it looks to function normally.

u/Petnek — 1 month ago

Old but still good

Recently I switched from Garmin Fenix line to "disconnected" watches. It's awesome, so peaceful without notifications or need to check various gathered numbers. Here are my old Edifice EF-328, revived with new battery just for office work.
I've got also G-Shock GW-M5610U and GA-B2100DF-1AER and like them very much.

u/Petnek — 1 month ago
▲ 56 r/gshock

Couldn't resist. GA-B2100DF

When I saw these GA-B2100DF, I simply couldn't resist. Collaboration with Charles Darwin Foundation was the last detail I needed to convince myself 🤭.
I plan to wear them to the nature, zoo, Radiacode terrain research and no city family trips.

u/Petnek — 1 month ago
▲ 7 r/kia

Your opinion on Kia Ceed SW 1.5 T-GDi, year 2022

Hi, I see here posts from United States, I suppose, and I'm not sure if this model was sold there. I would like to ask from Europe anyway.
Is here someone who can give me an advice on what to be beware of before buy in title mentioned used car? In my scope are cars specifically with this engine from years 2021 to 2023. Are there some red flags?
So far I read about automatic transmission, so I go for manual one.

u/Petnek — 2 months ago

Unexpected elevated background at a sports area in Tábor, Czech Republic. Possible imported fill material?

During a run with my Radiacode 102 at the Komora sports area in Tábor, Czech Republic, I noticed something unusual.
The entire area was consistently showing about +10 CPS above the surrounding environment, and at one spot I measured up to 0.26 µSv/h.
What makes it interesting is that this was not just a tiny hotspot. The elevated readings covered a relatively large modified terrain area.

Here is the Radiaverse map segment:
Radiaverse map location

My first thought is that the terrain may have been landscaped using imported material with naturally elevated radioactivity, possibly crushed granite, industrial aggregate, or soil containing more uranium/thorium-bearing minerals than the local background.

The surrounding area is noticeably lower, so the transition is quite visible.

Has anyone else found large “artificial” elevated background zones around sports fields, parking lots, or landscaped public areas?

u/Petnek — 2 months ago

I noticed that the same feature request was already discussed here about three years ago, so I wanted to ask whether there has been any consideration of implementing it since then. How do you resume a spectrum measurement? : r/Radiacode

I’d really like to see a feature allowing saved spectroscopy sessions to be resumed later instead of always starting from zero.

For weak sources, long acquisition times are extremely important, and this could significantly improve spectrum quality and isotope identification. Many of us don’t have two devices available, so when using a Radiacode as an everyday dosimeter, it’s difficult to leave it measuring one sample continuously for 12–24 hours or even longer.

A “resume spectroscopy” option could make long-term measurements much more practical:
• continue measuring the same sample over multiple sessions/days
• build better statistics for weak sources
• improve peak visibility and identification confidence
• reduce the need for uninterrupted measurements

Of course, keeping the measurement conditions consistent would still be the user’s responsibility. Same geometry, same distance, similar background conditions, etc.

Even with that limitation, I think this could be a very useful advanced feature for hobby spectroscopy users.

Has the idea evolved any further since the previous discussion?

reddit.com
u/Petnek — 2 months ago

I recently checked an old watch that belonged to my grandmother, and it seems to be my first real radium-related find.

I measured it with a RadiaCode-102. The dose rate close to the watch is around 1.6 µSv/h.

I also collected a longer gamma spectrum:
Watch measurement: 3 h 31 min
Background measurement: 3 h 30 min
Watch: average about 60 cps
Background: about 9.2 cps
Net difference: about 50 cps above background

After background subtraction, the spectrum shows peaks consistent with the Ra-226 decay chain, especially Ra-226 itself and its daughters Pb-214 and Bi-214.
The most visible lines are around:
186 keV, consistent with Ra-226
242, 295 and 352 keV, consistent with Pb-214
609, 1120 and 1765 keV, consistent with Bi-214

I have not opened the watch and I do not plan to. I know the main concern with old radium watches is not just external dose, but possible contamination if the paint is damaged or disturbed.

For me, this is a fascinating find. It is one thing to read about radium-painted watches, but seeing the spectrum from an old family object makes it feel much more real.

u/Petnek — 2 months ago

I recently found an old watch that belonged to my grandmother. Out of curiosity, I measured it with my Radiacode 102, and this turned into my first proper gamma spectrum from this kind of find.

The dose rate near the watch is about 1.6 µSv/h.

I also made a longer measurement:
Watch measurement: 3 h 31 min
Background measurement: 3 h 30 min
Watch: average about 60cps
Background: about 9.2 cps
Net difference: about 50 cps above background

After subtracting the background, the spectrum shows clear peaks consistent with the Ra-226 decay chain, especially:
Ra-226 around 186 keV
Pb-214 around 242, 295 and 352 keV
Bi-214 around 609, 1120 and 1765 keV

For me, this is a pretty fascinating find. It is one thing to read about radium paint in old watches, but seeing the spectrum from a family object makes it feel very real.

I have not opened the watch and I do not plan to. It will be stored safely as a collectible, not worn.

u/Petnek — 2 months ago