Community Input Bolsters New ReportReassuring Residents On PAVE PAWS
Community Input Bolsters New ReportBy George Heufelder, MS, RS, Director,
Barnstable County Department of Health & Environment
This past December, the Massachusetts Department of Public Health (DPH), Bureau of Environmental Health, and Community Assessment program released the report titled “Evaluation of the Incidence of the Ewing’s Family of Tumors on Cape Cod, Massachusetts and the PAVE PAWS Radar Station.”
The results were reassuring and concurred with a multi-year investigation of the public health effect of PAVE PAWS conducted with the oversight of the PAVE PAWS Public Health Steering Committee consisting of public health officials from surrounding towns and the state.
The DPH report also concurred with a review by the National Research Council of the National Academy of Science that concluded in 2005 that there was “no evidence of adverse health effects to Cape Cod residents from long-term exposure to radiofrequency energy from a nearby U.S. Air Force radar installation”
The 2007 DPH study was conducted in response to some citizens who felt that the higher incidence of the rare form of cancer called Ewing’s Sarcoma warranted another look at possible exposures from PAVE PAWS.
While the DPH and other reports regarding PAVE PAWS are reassuring regarding that facility, questions remain when the incidence of any cancer appears to be higher than should be expected.
This phenomenon, often called a “cluster,” is perhaps the greatest challene to public health epidemiologists, who study the causes, distribution and control of disease in populations.
“It is important to investigate clusters” says David Schottenfeld, M.D., M.Sc., professor of epidemiology and internal medicine at the University of Michigan, who adds that unfortunately it is “very rare” for a cancer cluster to be scientifically linked to a specific environmental cause outside of the occupational setting.
Dr. Schottenfeld further states, “The vast majority of cancer clusters are just random aberrations.”
Despite the difficulties with investigating clusters, each inquiry to local and state health departments is carefully considered.
A systematic approach is employed that manages requests for investigation without depleting resources.
Investigations begin with carefully reviewing existing and historic data on both the disease occurrence and environmental factors.
For cancer incidence, health officials in Massachusetts rely on the Massachusetts Cancer Registry (MCR). Massachusetts regulations require that “every healthcare facility shall report to the Cancer Registry every case of malignant disease and benign brain related tumor disease diagnosed, evaluated, treated, medically supported or palliated at that health care facility.” Further, if a facility is asked to treat a tumor that has not previously been diagnosed at that facility, it must report the disease to the registry. Any citizen can view these data themselves by accessing the online incidence tables for each town. Just use a search engine and enter the words “Massachusetts Cancer Registry.”
The MCR is one of the best in the country, and health officials investigating suspected clusters routinely are able to go beyond simple use of the town-by-town tables to determine patterns.
Often, they do this with help from community members who have assembled information that may not have been otherwise gathered, and applying various alternative means of grouping and analyzing the data.
Any time it appears that there is an unusual rate of disease in an area, various parallel efforts will often ensue. One involves the validation of existing disease cases by verifying residence times and comparing them with known periods of disease latency. In addition, due to the usually-low overall incidence of a disease, the statistical tools are reviewed for relevancy and adherence to assumptions that keep the tests valid. Concurrently—and again often with help from community members—health officials may locate all sources of available environmental data. These include existing and past land uses, environmental exposures and drinking water quality. These efforts can help determine possible plausible connections between known or suspected risk exposures and the disease.
In short, the investigation of suspected cancer clusters in any community is a complex and expensive task requiring both top-notch expertise and community involvement.
Given all this community input, I believe the recent studies that investigated the relationship of the PAVE PAWS operation with cancer (and more recently with Ewing’s Sarcoma), were successful in addressing many concerns regarding the operation of that facility.
The communities’ continued participation and encouragement of another study involving an apparent leukemia cluster will be paramount to ensure a similar successful outcome.