Safety_Series_025_1968 - gnssn - International Atomic Energy ...

This publication is no longer validPlease see http://www.ns-iaea.org/standards/his suitability for the type of work to which it is proposed to assignhim, to keep a regular record of this health during employment and,subsequently, to intervene in the event of any late occupationaldisease.4. 2. 3. 1. Pre-employment supervisionBefore any worker liable to exposure to radiation is engaged,a report should be established to serve two purposes; firstly, toserve as a basis for determining to what extent the past history andthe present condition of the worker make it possible to regard himas fit or unfit for the type of work for which he is being considered;and secondly, if he proves fit for such work, to serve as a referencepoint for any subsequent changes due to the hazards of thatwork. Every worker should therefore undergo a pre-employmentinquiry and medical examination.4. 2. 3. 1. 1. Medical history. As explained above, the inquiry hasthe purpose of determining the candidate's hereditary, personal andoccupational history. It is of particular importance that all previousirradiations be noted, for which purpose an account shouldbe kept of external exposures and an attempt made to obtain as muchdata as possible on any radioactive contamination. A gammaspectrometricalexamination may be useful for evaluating as appropriatethe present body burden of gamma-emitting nuclides. In theanalysis of previous exposures, a.distinction should be made betweenthose due to work with radiation and those due to radiological examinationor treatment. The former must be taken into account later,during employment, for the assignment of maximum perm issiblecumulative limits. The latter, however, should be ignored whendetermining the accumulated dose, although they should still be carefullynoted. In some cases, especially after extensive radiotherapy,an additional occupational exposure might seem inadvisable. Onlythe medical officer, however, is qualified to determine to what extentsuch previous therapeutic irradiations are compatible with subsequentwork involving radiation hazards taking into account the environmentof work as well. Any possibility of previous poisoningby radiomimetic substances must also be recorded. Although itis difficult to establish a precise relationship between the effect ofradiomimetic substances and that of radiation, there is no doubt thatprevious poisoning, especially by hydrocarbons, may be a factor1 0 9