Emergencies
Examples of radiation doses and external dose rates
Radiation doses
|
Dose rate |
What the rate causes |
|---|---|
|
6000 mSv |
A dose that when received within under 24 hours causes radiation sickness and can be fatal. |
|
1000 mSv |
The dose which may cause symptoms of a radiation sickness (e.g. tiredness and nausea) if received within 24 hours |
|
20 mSv |
The highest permitted dose for a radiation worker over a period of a year |
|
5.9 mSv |
The average annual radiation dose for Finns caused by indoor radon, X-ray examinations, etc |
|
2 mSv |
The annual dose of cosmic radiation received by a person working in an aeroplane |
|
0,1 mSv |
The radiation dose received by a patient having his/her lungs X-rayed |
|
0,01 mSv |
The radiation dose received by a patient having his/her teeth X-rayed |
External dose rates
|
Dose rate |
Example |
|---|---|
|
100 µSv/h |
It is necessary to take protective measures, e.g. to shelter indoors |
|
30 µSv/h |
The dose rate measured at a distance of one metre of a patient that has undergone isotope treatment. When the dose rate is less than 30 µSv/h, the patient can be discharged. |
| 10 µSv/h | Some protective measures are needed, e.g. avoiding being outdoors unnecessarily. |
|
5 µSv/h |
The highest dose rate measured in Finland during the Chernobyl accident |
|
5 µSv/h |
The dose rate in an aeroplane flying at an altitude of 10 kilometres |
|
0.2–0.4 μSv/h |
The dose rate which, if it is exceeded, causes an alarm in an automatic radiation monitoring station in the Finnish automatic external dose rate monitoring network. Each station in Finland has its own station-specific alarm level, which is determined separately for each station. Alarm levels in Finland are between 0.2 and 0.4 μSv/h. The differences are mainly caused by the level of natural radioactivity in the soil surrounding each sensor. |
|
0,04-0,30 µSv/h |
Natural background radiation in Finland |
The radiation dose describes the health hazard caused by radiation. Its unit is sievert (Sv). The dose is often given in thousandths of sieverts, i.e. millisieverts (mSv) or in millionths, i.e. microsieverts (µSv).
The dose rate indicates the amount of radioactive dose received by a person within a certain period of time. The unit of the dose rate is sieverts per hour (Sv/h).