Epidemiology of Childhood Leukaemia in Northumberland and Durham

The cases of leukaemia accepted for analysis were those (a) with onset before the 15th birthday, (b) which occurred within the geographical limits of Northumberland, Durham, and that strip of the North Riding of Yorkshire between the Cleveland Hills and the River Tees, (c) with onset between January 1, 1951, and December 31, 1960, a total of 10 years.