Because of the size of the report, the appendices to the Broadcast Signal Lab (BSL) report (itself an appendix to the MDPH report) are not included. If you have any questions regarding the report or would like a hard copy of the BSL appendices, please contact MDPH at (617) 624-5757.
Questions and Answers
Why did the Massachusetts Department of Public Health (MDPH) evaluate the incidence of the Ewing's Family of Tumors (EFOT) on Cape Cod, Massachusetts?
In 2004, a resident of Sandwich contacted the MDPH about a suspected increase in the incidence of cancer among children in Sandwich. In response to this request, the Community Assessment Program (CAP), a division within the Bureau of Environmental Health (BEH) at the MDPH, released a report of its initial evaluation at a public meeting in February 2006. MDPH proposed a focused study of childhood cancer in Sandwich, Mashpee and Barnstable due to an unusual pattern of disease in these areas of upper Cape Cod. At the public meeting, residents also voiced concern about the incidence of EFOT in individuals of all ages (children and adults) and across the entire Cape and the possible role that emissions from PAVE PAWS may have played.
What is meant by the Ewing's Family of Tumors (EFOT)?
Ewing's Sarcoma was first identified by Dr. James Ewing in 1921 when he observed that this type of bone tumor was different from the more common type of bone cancer known as osteosarcoma. Since his discovery, this tumor has also been observed in soft tissues. These soft tissue tumors are referred to as extraosseous (outside bone) Ewing (EOE). A third type of tumor shares many of the same features as Ewing's and EOE and it is called a peripheral primitive neuroectodermal tumor (pPNET). These three tumors make up the EFOT.
Why did this evaluation include environmental measurements of PAVE PAWS radar station emissions?
As mentioned, at the February 2006 public meeting, some residents felt that a recent report released by the U.S. Air Force did not provide measurements specific enough to determine whether PAVE PAWS could have played a role in the incidence of EFOT. In addition, some residents voiced concern that earlier studies focused on average emissions from PAVE PAWS while it may be important to measure maximum emissions. Given that the National Research Council, in its review of potential health effects from exposure to PAVE PAWS emissions, concluded that there are no adverse health effects to the Cape population resulting from continued or long-term exposure to the PAVE PAWS radiation, but could not address exposure at the level of the individual, MDPH worked with Broadcast Signal Labs (BSL), an engineering company, to take measurements of the radar facility's emissions in close proximity to the homes of individuals with EFOT or locations frequented by individuals with EFOT and in comparison areas. BSL measured what are referred to as peak power density levels (as opposed to average power density levels) at 31 sites across Cape Cod.
What is the PAVE PAWS Radar System?
The PAVE PAWS Radar System is solid-state, phased-array radar, which is operated by the Air Force Space Command on the Massachusetts Military Reservation (MMR). PAVE is an Air Force program name, while PAWS stands for Phased-Array Warning System. The radar is used to provide warning of sea-launched and intercontinental ballistic missiles. The PAVE PAWS facility also detects and tracks earth-orbiting satellites.
PAVE PAWS radar transmits pulsed radio frequency signals within the frequency range of 420 to 450 megahertz (MHz). These signals are reflected back by objects of interest. The returned signals are analyzed to determine the location, distance, size and speed of the object. The energy of PAVE PAWS is emitted in the portion of the radio spectrum called UHF (Ultra-High Frequency). This band of radio frequencies contains other emissions more familiar to the general public (e.g., UHF television transmissions, public safety radio communications, business communications, and wireless communications). Phased-array radar is also commonly found on US Navy ships and in the US Army's Patriot air defense missile system.
How common is the EFOT?
According to the American Cancer Society, about 250 children and adolescents are diagnosed with a cancer in the EFOT in the United States each year. According to a medical journal article on EFOT, the annual incidence of Ewing's sarcoma in the United States in white young people less than 21 years of age is two to three cases per million. (The EFOT is very rare among African Americans.) Nationally, 2% to 3% of all childhood tumors are in the EFOT. Using national data available from the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) program, MDPH computed both a national and statewide age-adjusted incidence rate for the EFOT for the 10-year period 1995-2004. The U.S. and Massachusetts average annual age-adjusted incidence rates are similar: 2.2 and 2.3 diagnoses per million, respectively.
What data were used to evaluate the incidence of EFOT on Cape Cod?
To evaluate the incidence of EFOT on Cape Cod, MDPH used data from the Massachusetts Cancer Registry (MCR). The MCR, part of MDPH, collects information on new cancer diagnoses among Massachusetts residents. The ten-year period 1995-2004 is the most recent period for which complete statewide data were available to calculate incidence rates. In addition, because the MCR is a continual surveillance system, it was possible to review case reports for more recent years (2005 to the present) to determine if additional diagnoses of EFOT were made on Cape Cod in these later years.
How did MDPH evaluate the incidence of EFOT on Cape Cod?
To determine whether an elevation exists among individuals with a diagnosis included in the EFOT on Cape Cod, cancer incidence data were tabulated according to eighteen age groups to compare the observed number of cancer diagnoses to the number that would be expected based on the statewide cancer rate. Standardized incidence ratios (SIRs) were then calculated for the ten-year time period 1995-2004.
How did MDPH review the temporal and geographic distribution of the EFOT on Cape Cod?
MDPH sought the assistance of two pediatric oncologists to evaluate the patterns of EFOT on Cape Cod. The year of diagnosis for each individual was reviewed to determine if a temporal pattern existed among individuals diagnosed with an EFOT on Cape Cod. Additionally, the address at the time of diagnosis for each individual diagnosed with an EFOT on Cape Cod was mapped using a computerized geographic information system (GIS). This allowed assignment of location for each individual diagnosed with an EFOT and an evaluation of the spatial distribution of the individuals at a smaller geographic level within communities. This evaluation also included consideration of the population density variability of each community through the use of GIS-generated population density overlays. GIS information on individuals' residences at the time of diagnosis was also evaluated in relation to the measurements taken for PAVE PAWS.
What did the study find regarding the incidence of EFOT among children on Cape Cod?
Seven children were reported to the MCR with a diagnosis of EFOT when approximately two would be expected.
What did the environmental data collected by BSL show?
Environmental measurements related to the PAVE PAWS radar facility at the Massachusetts Military Reservation, taken at 31 locations across Cape Cod, showed that the measured peak pulse power levels at the index sites (locations in close proximity to the individuals diagnosed with an EFOT or locations frequented by the individuals) were very similar to those measured at comparison sites (locations similar in their relationship to PAVE PAWS as the index sites but not near the residences of individuals diagnosed with an EFOT).
Was the geographic distribution of the EFOT unusual on Cape Cod?
With one exception, no geographic or spatial clustering was noted when the place of residence at diagnosis was mapped for each individual diagnosed with a tumor in the Ewing's Family. Although two individuals lived in close proximity to one another at the time of their diagnosis, their diagnoses were approximately five years apart. Further, environmental measurements from PAVE PAWS at their homes were similar to one another, as would be expected due to their proximity, and were not in the highest quartile of peak pulse power densities measured for index sites.
Was the temporal distribution of the EFOT unusual on Cape Cod?
Temporal clustering was noted in the years 2003 and 2004, with five individuals diagnosed with a tumor in the Ewing's Family in these two years. It is important to note that two of these individuals lived at their residences for less than one year making it less likely that residence on Cape Cod was associated with their diagnoses. Additionally, the peak pulse power density measurements from PAVE PAWS in the vicinity of these five individuals' homes were not in the highest quartile of measurements for the index sites. Three were in the lowest quartile for index sites.
What does MDPH conclude from these results?
Based on the information above, it appears unlikely that PAVE PAWS played a primary role in the incidence of EFOT on Cape Cod. In addition, although temporal clustering was noted in the years 2003 and 2004, for two of the five individuals diagnosed during this period, their residential history information revealed that they lived at their residence of diagnosis on Cape Cod for less than one year before diagnosis, making it less likely that residence on Cape Cod was associated with their diagnosis.
Does MDPH recommend any follow-up?
MDPH will continue to monitor the incidence of EFOT on Cape Cod and will work together with the medical community, local health officials, and community residents as appropriate.
Where can I obtain a copy of the report Evaluation of the Incidence of the Ewing's Family of Tumors on Cape Cod, Massachusetts and the PAVE PAWS Radar Station?
The full report is available on the MDPH website at http://www.mass.gov/dph/environmental_health.
Who should I contact for more information?
Massachusetts Department of Public Health
Bureau of Environmental Health
Attn: Community Assessment Program
250 Washington Street, 7th Floor
Boston, MA 02108
Phone: (617) 624-5757
Fax: (617) 624-5777
This information is provided by the Environmental Epidemiology Program within the Department of Public Health.