Population Estimates and Surface and Gonadal Exposure from Medical X-Ray Use in New Orleans, 1962-1963

摘要

The New Orleans Study was a prospective universal study which included institutional populations. Tables have been prepared for both resident only and resident and non-resident populations. A statistical model, based upon laboratory data, has been developed to calculate skin and gonadal exposure from recorded technical parameters of x-radiation exposure of each patient studied. There were 777,000 estimated examinations of which 55% were on males and 45% on females. The chest examination represents 51%, abdominal studies 16%, and lower spine and pelvis 7% of all examinations performed in the study area. There were 1,631,700 estimated projections which represent 2.1 projections per examination. The peak number of projections occur in the 30-59 year age group. The estimated average male gonad exposure is 87 mR with the peak occurring in the 65-69 year age group. The estimated average female gonad exposure is 133 mR with a peak occurring at 20-24 years. This peak is due to obstetrical examinations. The estimated genetically significant dose for the New Orleans population was calculated at 75.2 mR with 43.7 mR for females plus fetus and 31.5 mR for males. Abdominal examinations wherein the gonads may be in or near the central beam contribute 97% of the genetically significant dose, but represent only 20% of all examinations on the resident population. The obstetrical examinations constitute the largest proportion of the genetically significant dose for any single examination, about 31% of the total.