Radiation Monitoring

[Joe]

Checks this week have ranged between 0.1 to 0.19 micro Sv, nothing concerning has been noted and more importantly checks have been made on rain samples and all are normal.
Will continue monitoring this week.

[Beardy_McNormous]

What hardware do you have Joe?

[Straight Shooter]

0.09 micro Sv at 5.30 pm ....location South Wales .

[Straight Shooter]

0.11 micro Sv at 8.28 Am 14-03-2022

[Straight Shooter]

O.21 micro Sv 16.30 14-03-2022 .

[Joe]

Beardy I use the Radex 1503, pretty basic but sensitive for low levels. In fact my trigger source for testing is a smoke alarm.

[Joe]

What’s your baseline levels for your location SS, do you vary much.

[Pete Grey]

Not knowing much about the levels of radiation deemed to be “normal” or safe I thought I should find out.

The International Commission on Radiological Protection ( ICRP) recommend 20 millisieverts per year as an occupational effective dose (this is the accumulative dose) a limit 50 millisieverts is allowed providing the average over 5 years does not exceed 20 millisieverts per year. A whole CT body scan is 15-20 millisieverts.

1000 microsieverts is 1 millisievert, and 0.2 microsievert/hour is less than 2 millisieverts a year.

Incidentally anyone flying at 40,000 feet will receive a dose of between 3 and 9 microsieverts/hour due to cosmic radiation.

This puts things in perspective.

Any way SS and Joe thanks for the information.

[Joe]

Pete the slight problem with official figures is knowing how to interpret them. What you really need to do is get to know your meter and the expected levels in your area.
For example I use a very sensitive meter and I can read down to 0.1 micro Sv, my baseline level for this area is around 0.1 to 0.25 micro Sv ( baseline is just your normal expected readings in your area).
You might find other areas could have a level of 0.3 micro Sv or higher but this is still normal and just depends on the geology in your area.
What people need to know is abnormal levels in their area, for example if I seen 10 micro Sv I would sit up and take notice but I am still perfectly safe. I would be investigating the reason and be preparing for increased levels. When I see 100 to 1000 micro Sv I would be taking action and checking wind direction and navigating to a safer area.
Now 1000 micro Sv (1 milli Sv) is not the end of the world but I wouldn’t be hanging around. At this level you are in an event and need to be thinking and planning some course of action.
Additionally always know the location of all nuclear plants in your area.
Plus always have a test and calibration source, if you don’t have anything an old smoke alarm will give you around 0.5 micro Sv or higher.

[Joe]

Dental x-ray 0.005 mSv
100g of Brazil nuts 0.01 mSv
Chest x-ray 0.014 mSv
Transatlantic flight 0.08 mSv
Nuclear power station worker average annual occupational exposure (2010) 0.18 mSv
UK annual average radon dose 1.3 mSv
CT scan of the head 1.4 mSv
UK average annual radiation dose 2.7 mSv
USA average annual radiation dose 6.2 mSv
CT scan of the chest 6.6 mSv
Average annual radon dose to people in Cornwall 6.9 mSv
CT scan of the whole spine 10 mSv
Annual exposure limit for nuclear industry employees 20 mSv
Level at which changes in blood cells can be readily observed 100 mSv
Acute radiation effects including nausea and a reduction in white blood cell count 1000 mSv
Dose of radiation which would kill about half of those receiving it in a month 5000 mSv