Regulations regarding personal radiation dosimetry
The ‘personal radiation dosimetry’ regulations describe a method for calculating whether persons working on given premises are required to wear a personal dosimeter.
Personal radiation dosimetry is used to measure how much ionising radiation an employee can be exposed to within a given period of time. If a risk assessment shows that an employee cannot be exposed to more than 1 mSv per year, the employee is not required to wear a personal dosimeter. From 1 mSv upwards, the employee in question is assigned to category B (up to 6 mSv per year) or to category A (up to maximum 20 mSv per year) and required to wear a personal dosimeter. Every four weeks (category B) or 2 weeks (category A) the dosimeter is read out and the results are examined by the radiation expert. The legal limit to the dose to which an employee can be exposed is 20 mSv per year. The average natural dose of radiation per inhabitant in the Netherlands is approximately 2.5 mSv.
If an employee is planning to work with radioactive substances or x-ray devices, the radiation expert will assign this employee to a category and if necessary provide him or her with a dosimeter. Within Leiden University, there are at present no work activities involving ionising radiation with an exposure dose of more than 1 mSv. These employees fall into the so-called C-category, for whom a personal dosimeter has no added value. The university regulations on ‘Personal Radiation Dosimetry’ specify how this dosimetry is implemented.