1. At its meeting in November, 1959, the Executive Committee agreed that the NCRP should make a statement with regard to the maximum permissible dose from television receivers. Such a statement has been prepared and voted upon by the full committee.
The following position has been adopted by the NCRP:
During the past years, members of the NCRP have investigated the emission of x rays from television receivers. From a genetic point of view even sources of minute radiation are of significance if they affect a large number of people. X rays emitted by home television sets are, therefore, of interest because of the high percentage of the population involved. In order to insure that the television contribution to the population gonad dose will be only a small fraction of that due to natural background radiation, the NCRP recommends that the exposure dose rate at any readily accessible point 5 cm from the surface of any home television receiver shall not exceed 0.5 mr per hour under normal operating conditions.
Laboratory and field measurements1 have shown that with this maximum permissible exposure level the television contribution to the gonad dose at the usual viewing distances will be considerably less than five percent of that due to the average natural background radiation. Most of the present television receivers already meet this requirement with a high factor of safety. In general, therefore, no changes in shielding of existing sets will be required. However, the recommended limit will insure that future television receivers, operating at higher voltages, will not contribute significantly to the population gonad dose.
2. In its statements of January 8, 1957 and April 15, 1958, the NCRP specified a permissible dose of 10 (N – 18 rems) to the skin of the whole body for a radiation worker. It has subsequently been realized that the use of the age-proration formula for the skin of the whole body is not practical under some conditions. Therefore, the Committee will discontinue this statement and in its place make the following recommendation:
Skin of the whole body:
The maximum permissible dose to the skin of the whole body shall not exceed 30 rems per year and the dose in any 13 consecutive weeks shall not exceed 10 rems.
This statement is essentially the same as in the 1959 ICRP report except that the ICRP specified a 13-week limitation of 8 rems. It is felt that this is unnecessarily low if the annual limit is 30 rems.
3. The above changes will be incorporated in the appropriate reports of the NCRP as the case arises.
1Braestrup, C.B. and Mooney, R.T. (1959). “X-ray emission from television sets,” Science, Oct. 23, 1959, 130, 1071-1074.