Table 5.

History of radiation protection standards and estimated occupational doses of medical radiation workers^a

Source of information Author(s), Yr	Year(s) of recommendation, estimated doses	Radiation protection recommendation or standard	Estimated doses to medical radiation workers	Comments: historical events, organization(s) proposing protection standard, and others
Inkret et al., 1995	1902	Standard ~ 100 mGy/dayb	~30 Gy/yrb	Not based on biological data but based on lowest amount easily detected by fogging on photographic plate
Quimby, 1926	1926		Mean 0.0031 skin unit dose/wk (~900 mSv/yr)	Memorial Hospital, New York City, workers carried unexposed film
Fricke and Beasley, 1927	1927		Estimated doses of 0.065 skin unit dose/mo (~4,5000 mSv/yr)	Cleveland and New York measurement of stray radiation
Mutscheller, 1928	1928	Proposed tolerance dose limit of 1/100 erythema dose/mo (~700 mSv/yr)	Estimated doses of 1/10 erythema dose/mo (~7000 mSv/yr)	Based on observations of physicians and technicians in shielded work areas
Brodsky et al., 1995	1928	Roentgen unit (R) adopted		Second International Congress of Radiology
Braestrup, 1957	1920s & 1930s		Estimated doses of 100 R/yr (~1000 mSv/yr)
Brodsky et al., 1995	1931	Standard: 0.2 R/dy (~500 mSv/yr)		Standard proposed by U.S. Advisory Committee on X-ray and Radium Protection (ACXRP)
Brodsky et al., 1995	1936	Recommendation: 0.1 R/dy (~250 mSv/yr)		Recommendation by ACXRP
Hall, 2000	1937	Roentgen unit accepted as international dosage unit for x- and γ-radiation		Proposed by Fifth International Congress of Radiology
Simon et al., 2006	Before 1939		Estimated mean dose of 100 mSv/yr	Annual badge dose prediction for U.S. radiologic technologists working in hospitals
Cowie and Scheele, 1941	1940		Mean 0.02R/dy (~50 mSv/yr)	Survey of 45 hospitals
Simon et al., 2006	1940–49		Estimated mean dose of 25 mSv/yr	Annual badge dose prediction for U.S. radiologic technologists working in hospitals
Geist et al., 1953	Early 1950s		Estimated dose 0.1R – 0.3R/wk (~50 – 150 mSv/yr)
Braestrup, 1957	1957		Mean 1 R/yr (~10 mSv/yr)	Based on 138 radiologists in a New York hospital monitored with film badges
Zielinski et al., 2009	1951–1987		Mean badge doses: 1.66 and 0.54 for 1951–70 and 1971–87, respectively for diagnostic radiologists; 1.13 and 0.32 for 1951–70 and 1971–87, respectively for radiologic technologists	Data from Canadian national dose registry of radiation workers
Andersson et al., 1991	1954–82		Mean cumulative dose = 18 mSv (17% had zero exposure, 9% had >50 mSv	Staff members in two radiotherapy departments in Denmark
Inkret et al., 1995	1957	Recommended dose limit: 50 mSv/yr		Proposed by International Commission on Radiation Protection
Simon et al., 2006	1960–76		Mean badge dose: 3.6 mSv/yr	Annual badge dose predictions for U.S. radiologic technologists in hospitals
Webb, 1974	1964		Mean doses <5 mSv/yr	UK radiologists
UNSCEAR, 2000	1975–94		Mean dose: 1975–79=0.94 mSv/yr 1980–84=0.68 mSv/yr 1985–89=0.56 mSv/yr 1990–94=0.50 mSv/yr	International estimates for workers in diagnostic radiology
Simon et al., 2006	1977–84		Mean badge dose: 2.3 mSv/yr	Annual badge dose predictions for U.S. radiologic technologists in hospitals
Canadian National Dose Registry	1985-present		Mean badge doses: 1985=0.36 mSv/yr 1995=0.12 mSv/yr 2005=0.19 mSv/yr	Canadian diagnostic radiologists
ICRP, 1991	1990	Recommended dose limit: average 20 mSv/yr, averaged over 5-year period, and not exceeding 50 mSv in any single year		Proposed by the International Commission on Radiation Protection
Hughes and Riordan, 1993	1993		Mean dose: 0.5 mSv/yr	UK diagnostic radiologists
Watson et al., 2005	2001		0.15 mSv/yrMean dose:	UK diagnostic radiologists

^aDifferent types of dosimetric units and quantities have been reported in the literature. To compare the reported radiation doses, the original dose units (e.g., skin unit dose, R, etc.) were roughly approximated to current dosimetry units (e.g., mSv)

^bThe unit of absorbed dose (e.g., Gy) was not defined in 1902. The estimated dose in Gy is an interpretation in modern dose units of the measurement capability at that time based on fogging on a photographic plate