| Popis: |
A study of 533 brain tumors, 339 lung tumors, and 299 breast tumors was made in a contiguous six-county area of Kentucky to determine if a previous clustering of brain tumors with a rate 3.37 times the state rate still existed. No significant difference in incidence by age, sex, or race could be found between this six-county area and the entire state. It was therefore concluded that either the original study constituted a statistical artifact, or that the factors responsible for the initial observed increase are no longer operative. |
