Cancer Rates in the Four Towns
Wendy explains, "The Massachusetts DPH used calculated SIRs and 95% confidence intervals for eight different types of cancer (bladder, brain, kidney, liver, lung, leukemia, pancreas, non-Hodgkins lymphoma). Calculations were done for each of the four communities around the South Weymouth Naval Air Station. Most cancers occurred at or near the expected rates for the four towns, but there were increases in lung cancer in three of the four towns."
"These graphs show the SIRs and 95% confidence intervals for lung cancer for each of the four towns for the period from 1982-1998. The dashed horizontal line represents the null value. As you can see there were several significant increases, but there was no consistent pattern, and Hingham showed lower than average rates."
"They then looked at lung cancer SIRs within specific census tracts to get a more detailed picture of the geographic relationship of lung cancer to the SWNAS. There was no striking pattern of association in the two earliest time periods, but the pattern was noteworthy for the period from 1995 to 1998, shown below.
In the illustration below, the air station is shown in brown. Census tracts with statistically significant elevations in lung cancer are shown in pink. Increased rates that were not statistically significant are shown in blue."
Conclusions of MDPH Assessment
The Massachusetts Department of Public Health's Bureau of Environmental Health presented their findings at a public meeting on Feb. 13, 2002.
Assessment of Increased Cancer Rates
In summary:
- The geographic pattern of cancer did not show a clear pattern suggesting a common environmental exposure related to the NAS.
- Most cancer types occurred at or near the expected rates in the four towns between 1982-1998.
- Lung cancer is increasing in Weymouth and Rockland, particularly in census tracts near the air station. Except for lung cancer, no consistent spatial patterns were observed.
- Smoking likely played a role in increased lung cancer rates.
- Occupation also played a role in lung cancer for some individuals.
Despite this, there were concerns that sporadic elevations of arsenic in drinking water may result from varying environmental conditions in Great Pond (e.g., varying runoff) that may not be captured by testing required by drinking water regulations.
