Maximum permitted body burdens

The radiological hazard of tritium to operating personnel and the general population is controlled by limiting the rates of exposure and release of material. Maximum permissible concentrations (MPC) of radionucHdes were specified in 1959 by the International Commission on Radiological Protection (79). For purposes of control all tritium is assumed to be tritiated water, the most readily assimilated form. The MPC of tritium ia breathing air (continuous exposure for 40 h/wk) is specified as 185 kBq/mL (5 p.Ci/mL) and the MPC for tritium in drinking water is set at 3.7 GBq/mL (0.1 Ci/mL) (79). The maximum permitted body burden is 37 MBq (one millicurie). Whenever bioassay indicates this value has been exceeded, the individual is withdrawn from further work with tritium until the level of tritium is reduced. 

The maximum permitted body burdens of technetium nuclides are given in Table 5.5.A. 

Table 5.5.A Maximum permitted body burdens of some technetium nuclides [28].

This group, created by Congress, collects, analyzes, develops, and disseminates information and recommendations on radiation quantities, measurements, and units. NCRP publishes maximum permissible levels of external and internal radiation. The major handbooks are entitled Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and Water for Occupational Exposure and Review of the Current State of Radiation Protection Philosophy. The NCRP suggests an annual permissible whole-body dose of 5 rem/year, with 3 rem permitted within a 13-week period. 

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