Answer to Question #9532 Submitted to "Ask the Experts"

Category: Radiation Workers

The following question was answered by an expert in the appropriate field:


I work with radioactive sources in the oil rig industry. This month I got a dose of 6 mSv. The maximum exposure that I have ever had in a month was 1.5 mSv.

I have been barred from doing any radioactive source work now, but I am just concerned whether there will be any side effects for me because of this dosage. Is there any probability of getting cancer?


Thank you for your question. The dose you received won't cause any harmful effects.

Without knowing your company's procedures, my guess would be that they have temporarily removed you from radioactive source work to make sure you don't exceed any regulatory dose limits, not because of worries about harmful effects.

Regulatory dose limits are set well below levels of radiation dose that cause harmful effects. Generally, a person needs to receive about 500 mSv whole body to begin to see clinical biological symptoms which, in the case of 500 mSv, would be a decrease in blood cell counts.

In the United States, the annual radiation dose limit for a radiation worker is 50 mSv. In some areas of Europe, and perhaps where you work, it is 20 mSv. Both limits are below levels that cause harmful effects.

You didn't receive too much radiation—just enough, though, to cause your company to make sure they (and you) stay in compliance with regulations. This is a perfect example of what should happen to help keep workers safe.

Kelly Classic
Certified Medical Health Physicist

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 8 March 2011. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.