Gonad doses and genetically significant dose from diagnostic radiology: U.S., 1964 and 1970

In 1970, the United States Public Health Service conducted a nationwide study of population exposure to medical and dental x-ray examinations. In order to assess the change in radiologic practice, the results of this study were compared to the results of a similar study conducted in 1964. Data from these studies have been used to calculate mean gonad dose per examination and the Genetically Significant Dose (GSD) from medical radiographic examinations by age, sex, and type of examination for 1964 and 1970. The GSD was 17 mrads for 1964 and 20 mrads for 1970. The largest statistically significant increase in mean gonad dose per examination from 1964 to 1970 occurred for barium enema examinations of females (578 mrads to 903 mrads), and the largest statistically significant decrease for the same period occurred for intravenous or retrograde pyelogram examinations of males (537 mrads to 207 mrads). Eight other statistically significant changes in mean gonad dose per examination were observed. The difference between the estimated Genetically Significant Dose of 17 mrads in 1964 and 20 mrads in 1970 is not statistically significant