TRENTON - The New Jersey Department of Health and Senior Services (DHSS) and the federal Agency for Toxic Substances and Disease Registry (ATSDR) today released the final report, Case-Control Study of Childhood Cancers in Dover Township, as well as a report updating childhood cancer incidence data in the township through 2000.
Both reports were presented at a public meeting this evening at the Dover Township Municipal Building.
"We are pleased to present this final report and would like to thank the many people whose assistance and input were critical to the study's success," said James S. Blumenstock, senior assistant commissioner. "I would especially like to thank all the families who participated in this six-year investigation, as well as all the members of the public who offered their helpful and extensive comments on the draft report."
"The Dover Township study pioneered scientific methods and set new standards for the practice of environmental public health. It also sparked new research into childhood cancer around the country," said Juan Reyes, director of ATSDR's Office of Regional Operations. "We hope these efforts will lead to a better understanding of the role environmental exposures may play in the development of childhood cancer."
The final study report completes the six-year investigation of possible risk factors for childhood cancer in the township. Originally released in December 2001 as a draft report for public comment, the report released today contains changes based on extensive public input received during the three-month comment period ending March 19, 2002. These include clarification of the study's methodology and some additional analysis done at the request of commenters.
However, all of the study's findings, conclusions and recommendations released in the draft report remain the same.
The purpose of the case-control study was to identify possible disease risk factors that might explain why leukemia, and brain and central nervous system cancers were elevated among children in Dover Township and the Toms River section of the township. This included an examination of whether the higher rates were related to past environmental exposures, both to drinking water from specific public wells and contaminated private wells, and air emissions from the Ciba-Geigy chemical plant. Also examined were other potential exposures based on community concerns, including the Oyster Creek Nuclear Generating Station located several miles south of the township and others.
Study findings supported the hypothesis that past exposures to drinking water from certain contaminated public water supply wells, which have been closed or where treatment systems have now been installed, and to air emissions from the now-closed Ciba-Geigy manufacturing plant appeared to be risk factors for childhood leukemia in Dover Township females.
The study found that female children who developed leukemia were more likely than children without the disease to have had mothers who, while pregnant, were exposed to water from the Parkway well field during a period when it was most likely to have been contaminated, from 1982 to 1996. Mothers of female children with leukemia were also more likely to have been exposed to air pollutants from the Ciba-Geigy plant when it was operating.
The study did not find evidence that leukemia in male children, or nervous system cancers in male or female children, were associated with environmental exposures in the community. Exposure to water from the Holly Street well field during a period of most likely contamination did not appear to be associated with childhood cancer. In addition, no associations were found between cancer and air emissions from the Oyster Creek nuclear plant.
In conducting the study, the department used New Jersey State Cancer Registry data for cases diagnosed from 1979 through 1996. The study recommended the department analyze an additional five years of cancer incidence data when it became available. The cancer incidence report also released today outlines childhood cancer rates in Dover Township and Toms River for 1996-2000 as well as incidence trends for the 22-year period, 1979-2000.
According to the report, 25 new cases of childhood cancer were diagnosed in Dover Township from 1996 to 2000 - about four cases more than expected, though the difference was not considered statistically significant. This is in addition to the 87 cases recorded for 1979 through 1995.
"Based on 25 additional cases, it's difficult to determine whether or not childhood cancer rates are declining," said Jerald Fagliano, Ph.D, DHSS principal investigator on the epidemiologic study. "No new cancer cases in children under age five were diagnosed in the Toms River section of Dover Township in the most recent five years we examined. This is certainly a hopeful sign and may suggest a decline in cancer rates. We will continue to track trends in childhood cancer in Dover Township."
Compared with the state rates, none of the cancer incidence rates examined in 1996-2000 was statistically significantly elevated for the township or Toms River, the report notes. However, some cancer rates remained higher than expected. In Dover Township, brain and central nervous system cancers and leukemia in females were higher than expected, and leukemia was elevated in the Toms River section.
The report recommends the department continue its surveillance of childhood cancer in Dover Township, and update the analysis when another five years of data is available from the State Cancer Registry.
Copies of the reports are available by calling the department at (609) 588-3120. It is also available on the department's web site at http://www.state.nj.us/health/.
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