Occupational radiation exposure and health surveillance

The protection of radiation workers involves various measures, depending on the work tasks. These include the monitoring of exposure conditions, individual dose monitoring, health checks and health surveillance. Before starting radiation work, the employer assesses the need for protective measures on the basis of future work duties and working conditions. Information on the results of the workers' individual monitoring is recorded in the dose register maintained by the Radiation and Nuclear Safety Authority.

Dose register and extranet service

The dose register stores information on all employees under individual dose monitoring. The results of the monitoring of exposure conditions (e.g. doses determined based on group dosemeters) are not recorded in the register. The information is stored until the worker attains or would have attained the age of 75 years, but for at least until 30 years have elapsed from the termination of the radiation work. The information may be stored for longer than this for research purposes.

The information is used to ensure the radiation safety of radiation workers. In addition to the employee themselves, the information may only be disclosed to an occupational health physician familiar with radiation, the operator, and the employer of an external employee. This can be done if the information is needed for the monitoring of health, the classification of the radiation worker or the monitoring of the worker’s subsequent exposure. Each employer or operator has the opportunity to obtain an annual summary of the radiation doses caused to their employees.

The Radiation and Nuclear Safety Authority’s dose register includes an extranet service. Using this service requires personal access rights. A person appointed by the operator or the employer to handle matters related to the dose register, such as a radiation safety officer, as well as an occupational health physician familiar with radiation, may be granted access to the dose register’s extranet. Individual employees cannot be granted access rights. The extranet service of the dose register can be used, for example, to check annual summaries, to file reports related to abnormal doses and to order documents. The extranet service can also be used to print the dose report of an individual worker, which contains all their dose data that has been entered in the dose register.

Form: Extranet application (in Finnish)

Log in to the Dose register extranet service

Codeset of the dose register​​​​​​​​​​​​​​

Radiation work abroad

A so-called radiation passbook is required for radiation work performed abroad. The radiation passbook consists of the individual radiological monitoring document ordered from the Radiation and Nuclear Safety Authority and a medical certificate written by an occupational health physician who is familiar with radiation. The individual radiological monitoring document required for the radiation passbook is ordered from the Radiation and Nuclear Safety Authority. It contains information on the worker's previous radiation exposure. The medical certificate shows the worker's fitness for radiation work.

When a person performs radiation work in an EU country in which they are classified as a category A radiation worker, they must provide the radiation passbook to the foreign employer. It is also a good idea for other persons leaving for radiation work abroad to check the required documents in advance.

When a Finnish worker returns to Finland after completing radiation work abroad, the individual radiological monitoring document is returned to the Radiation and Nuclear Safety Authority. The foreign employer or dosimetry service shall record information concerning radiation exposure during working hours and the duration of work in the individual radiological monitoring document. The information will be entered in the dose register after the individual radiological monitoring document has been returned. A new individual radiological monitoring document can only be issued after the previous monitoring document has been returned. An individual radiological monitoring document can be ordered using an order form or the dose register’s extranet service.

Form: Report of the Workers Dose data and Individual Radiological Monitoring Document (in Finnish)

The category of the radiation worker, A or B, defines the necessary protective measures

It is the employer's duty to assess which workers are radiation workers. In addition, the employer classifies radiation workers into categories A and B. On the basis of the classification, the monitoring of exposure conditions, individual dose monitoring and health surveillance shall be arranged for each radiation worker to the extent required.

Flight crew and workers exposed to radon are not subject to the classification of radiation workers or health surveillance. For their part, exposure conditions are monitored and, if necessary, individual dose monitoring is also carried out using computational methods.

The basis for the classification is an assessment of the radiation exposure and potential exposure in the work. When assessing exposure, the effect of various radiation shields on exposure must be taken into account. Radiation work means work in which the effective dose may exceed 1 mSv per year. If this limit is exceeded but the dose is under 6 mSv, the worker belongs to category B.  If the worker’s exposure is higher than this, they belong to category A. In addition, any local skin exposure and the dose to the eyes must be taken into account. The worker’s health also has an effect on the work duties and the classification. A worker may only be classified in category A if an occupational health physician familiar with radiation has deemed the worker to be fit for such work on the basis of the worker’s health.

When assessing occupational exposure, the employer shall take into account all occupational radiation exposure, but non-occupational exposure shall not be taken into account. In this regard, the employer shall make as realistic an estimate as possible of the extent of the worker's exposure to radiation when the work is carried out as planned. Previous dose measurements and the results of the monitoring measurements of the exposure conditions may be used as background information. Literature can also be used. With regard to potential exposure, any events that can be expected to occur even if safety precautions are implemented shall be taken into account. These can include human error, equipment failure, use of inappropriate protective equipment, or poor working practices.

Occupational exposure is one part of the classification of radiation practices. For classification purposes, radiation work category A corresponds to category 1, and category B corresponds to category 2. A situation in which the dose limit for the general public is not exceeded corresponds to category 3. When classifying radiation practices, public exposure and medical exposure are taken into account in addition to occupational exposure.

Monitoring of exposure conditions

The monitoring of exposure conditions ensures that the working environment is safe. The observation of exposure conditions enables the detection of unforeseen deviations in factors with an impact on occupational exposure. Monitoring of exposure conditions shall be organized at all workplaces where radiation sources are used or where exposure to radiation is otherwise present. Monitoring of exposure conditions includes, for example, measuring the dose rate of external radiation and contamination measurements in the working environment, as well as making observations on whether the safety devices function as intended.

The use of a group dosemeter is also considered as monitoring of exposure conditions. When using a group dosemeter, it is necessary to know who has used the meter on each occasion so that the result can be used, for example, to determine the need for individual dose monitoring.

Individual dose monitoring

Individual dose monitoring means the measurement and determination of the dose to an individual worker arising from external and internal radiation. Radiation workers belonging in category A shall furthermore be arranged individual monitoring. The duration of the observation period shall not exceed one month. It is also often appropriate to arrange for individual monitoring for category B workers, but the monitoring period may be longer than one month, typically three months.

The individual monitoring shall be based on individual measurements performed by an approved dosimetry service. The dosemeter used for personal dosimetry shall only be used by one employee. The use of a group dosemeter does not count as dose monitoring. The results of individual monitoring are recorded in the dose register of workers, as maintained by the Radiation and Nuclear Safety Authority.

As regards external radiation, dosimetry services approved in Finland include those operating at TVO's Olkiluoto nuclear power plant and Fortum's Loviisa nuclear power plant, as well as Doseco Oy, which provides commercial dosimetry services. Approval for internal dose measurements is only available from the Radiation and Nuclear Safety Authority’s Measurements and environmental monitoring department.

Outside workers

Outside workers are employees of an outside undertaking and self-employed persons who are participating in radiation work for the operator without being employed by the operator.

The operator and employer of an outside worker are responsible for the radiation protection of the outside worker. They must ensure that the outside worker enjoys a level of protection equal to the operator’s own workers.

The employer of an outside worker always carries the overall responsibility for the worker’s safety. The employer is responsible, among other things, for ensuring that the worker's exposure remains within the permitted limits. All work involving exposure to radiation carried out by the worker concerned, on behalf of various operators, must be taken into account. The employer shall classify radiation workers into categories A and B and arrange for the necessary health surveillance. It is the employer's responsibility to provide the occupational health physician familiar with radiation with the necessary information for the monitoring of the employee's health.

For their part, the employer ensures that the worker has the necessary training, including in-service training, and induction into their duties. The employer shall also ensure that the results of individual monitoring are submitted to the dose register, even though it is the responsibility of the operator to arrange the monitoring of exposure conditions and individual monitoring. In practice, the dosimetry service submits the information to the dose register if the work is carried out in Finland. When working abroad, the matter must be taken care of separately.

It is the responsibility of the operator to ascertain the previous occupational exposure of an outside worker in advance. The operator must also assess in advance how much radiation exposure will be caused to an outside worker from the work for which it is responsible and how such exposure can be reduced. Furthermore, the operator must arrange the monitoring of exposure conditions and individual monitoring for the worker. The operator also ensures that the classification of an outside worker carried out by the employer is appropriate with regard to the practice for which the undertaking is responsible. The operator must ensure in other ways, as well, that the employer has taken care of its own obligations. If necessary, the operator and the employer may agree in writing on who will arrange the individual monitoring if it is to be carried out in a manner different from that described above.

Health surveillance

The purpose of health surveillance of radiation workers is to ensure that a worker is fit for radiation work and that the worker's state of health constitutes no impediment to performing the said work. Only an occupational health physician familiar with radiation, approved by Valvira as an occupational health physician familiar with radiation, may perform the health surveillance of a category A radiation worker. Valvira maintains a list of approved occupational health physicians familiar with radiation on its website.

A category A radiation worker shall undergo a pre-employment examination before commencing work. This is to determine that the worker is suitable for the job. In addition, annual health surveillance must be arranged. A worker may not be classified into category A or used in such work if they are unfit for it due to their health. There is no need for health surveillance for category B radiation workers for radiation protection reasons.

The employer shall inform the physician monitoring the radiation worker’s health of the worker’s category and shall provide information on the worker's duties and working conditions. Furthermore, the employer must provide the physician with information on the factors affecting radiation exposure in such detail that the physician is able to decide on the worker's fitness for work and on medical monitoring.

Fees for radiation practices regulations