1979: Woburn Health Data Analysis, 1969-1978
On December 21, 1979 the Massachusetts Department of Public Health published the Woburn Health Data Analysis, 1969-1978.
The summary of the report stated:
"The Department of Public Health has ascertained that Woburn's cancer death rate is higher than what should be expected considering the age and sex characteristics of its residents. However, we have not found data that associates a cause and effect relation between the Woburn cancer death rate and any specific cause. The Department has also determined that although the statistics are higher than what we would expect, they do not represent an epidemic situation. They do present some serious questions that need answers which we intend to pursue."
And the concluding paragraph said:
Cancer Mortality as an Indication of Cancer Incidence
The aggressive efforts by Reverend Young to find all of the leukemia cases had successfully identified all 12 of the incident leukemias that occurred during this 15-year period. However, the problem was that there was no way of knowing whether this incidence was unusual, since there was no data on cancer incidence in other communities in Massachusetts. As a result, the key question about whether 2 leukemia cases in a 15-year period was unusual remained unanswered. The lack of data on incident cases of cancer was a major limitation, and the following year the Massachusetts Cancer Registry was created and began to collect the data necessary to answer questions like this.
1981: Woburn - Cancer Incidence and Environmental Hazards, 1969 – 1978
Jimmy Anderson died on January 18, 1981. Five days later the Massachusetts Department of Public Health and CDC released an additional study that and concluded that the incidence of childhood leukemia in Woburn was significantly greater than expected. This study got around the lack of information in the rest of the state by using age- and sex-specific incidence data from the Third National Cancer Survey (TNCS). The key data for this comparison are summarized in Table 5 at the end of the study.
This investigation also included a case-control study; the Methods section of the published study described the case-control study as follows:
"The study questionnaire was developed, pretested, and revised by the MDPH and the CDC. The topics investigated included demographic information, disease process, past medical history, smoking, residence, schooling, occupational histories, and environmental exposures. The majority of the interviews were conducted by trained interviewers from the CDC and NIOSH. Two age and sex-matched controls were interviewed for each of twelve childhood leukemia cases. One control was a person of the same age and sex who lived close to the case. The other age and sex-matched controls lived in a distant part of Woburn. Interviews were conducted with one or both parents of the leukemia cases and controls."
The case-control study did not demonstrate any significant differences between the cases and controls that might provide clues about the cause of the cluster. Nevertheless, the comparison in Table 5 of the study did indicate that the incidence of leukemia was higher than expected based on a comparison with data from the Third National Cancer Survey.