Ionizing radiation is used in a wide range of settings and industries, such as medical diagnostic and radiotherapy, nuclear energy, X-ray systems at airports and even geological prospecting.

This means that many people are exposed to radiation at some level during their working day. However, safe exposure limits are a complex business because each organ in the body reacts differently. Skin, for example, needs to be protected from tissue reactions such as ulceration, while overexposure to the lens of the eye can cause cataracts.

Add to that the complexity of the exposure, whether it can be localized to one area of the body or not, and other considerations like weak penetration of radiation in matter…