Historical Evolution of Radiation Quantities and Units

Question 1

Xrs are discovered, and discovery is announced (Full date)

Answer 1

November 8, 1895

Question 2

Initial cases of somatic damage caused by exposure to ionizing radn are reported in Europe

Answer 2

1896

Question 3

Skin erthythema dose becomes the unit for measuring radn expo

Answer 3

1900

Question 4

1st American radn fatality and year

Answer 4

1904 Clarence Madison Dally

Question 5

First cancer deaths among physicians that are attributed to XR expo are reported

Answer 5

1910

Question 6

The British X-ray and Radium Protection Committee is formed to investigate methods for reducing radn expo

Answer 6

1921

Question 7

The First International Congress of Radiology is held in London, England; Radiologists from all over the world collaborate, but no definite system for measuring ionizing radn expo is identified

Answer 7

1925

Question 8

The International Commission on Radiation Units and Measurements (ICRU) is formed

Answer 8

1925

Question 9

The ICRU is charged by the Second International Congress of Radiology (Stockholm, Sweden) to define a unit of exposusre

Answer 9

1928

Question 10

The International X-ray and Radium Protection Commission (Predecessor of the ICRP) is established by the Second International Congress of Radiology

Answer 10

1928

Question 11

Tolerance dose is used for radiation protection purposes

Answer 11

1930s

Question 12

The U.S. Advisory Committee on X-ray and Radium Protection is formed to ormulate recommendations for radiation control

Answer 12

1931

Question 13

A tolerance dose of 0.2R per day is recommended

Answer 13

1934

Question 14

Tolerance dose is reduced to 0.1 per day

Answer 14

1936

Question 15

The Bragg-Gray Theory is introduced

Answer 15

1936

Question 16

The Roentgen (R) becomes internationally accepts as the unit of measure for expo to x-radiation and gamma radiation

Answer 16

1937

Question 17

The U.S. Advisory Committee on X-ray and Radium Protection becomes known as the National Committee on Radiation Protection and Measurements (NCRP)

Answer 17

1946

Question 18

International System of Units (SI) is developed

Answer 18

1948

Question 19

Maximum Permissible Dose replaces the tolerance dose for radn protection purposes

Answer 19

Early 1950s

Question 20

The Roentgen is redefined to increase accuracy and acceptability

Answer 20

1962

Question 21

The National Commission on Radiation Protection and Measurements becomes the National Councel on Radiation Protection (NCRP)

Answer 21

1963

Question 22

The International Commission on Radiation Protection (NCRP) recommends that the dose equivalent limit or effective dose equivalent replace MPD

Answer 22

1977

Question 23

The ICRU adopts SI Units for use with ionizing radn

Answer 23

1980

Question 24

The NCRP adopts SI Units for use

Answer 24

1985

Question 25

The ICRP replaces effective equivalent does with the term Effective Dose (EfD)

Answer 25

1991

Question 26

History of terms used to determine radn dose limitation

Answer 26

1900-1930 Skin Erythema Dose (SED)
1930-1950 Tolerance Dose (TD)
1950-1977 Maximum Permissible Dose
1977- 1991 Effective Dose Equivalent (dose equivalent limit)
1991-Present Effective Dose (EfD)

Question 27

History of terms used to determine NCRP

Answer 27

1931 U.S. Advisory Committee on X-ray and Radium Protection

1946 National Committee on Radiation Protection and Measurements (NCRP)

1963 National Council on Radiation Protection