[I]n Woburn, … the rate of childhood leukemia is four times what would be expected for a community of its size. Twenty-eight cases have been reported since 1964, making it, according to the federal Centers for Disease Control, the most persistent leukemia cluster in the United States. Sixteen of those cases have ended in death.
[Source: http://www2.shore.net/~dkennedy/woburn_mit.html]
The map below illustrates the distribution of childhood leukemia in Woburn from 1964 to 1986.
Photograph from the collection of Professor Scott Bair, Ohio State University.
[Source: http://www.geology.ohio-state.edu/courtroom/leuk4lg.jpg]