Trenton, NJ 08625-0360
December 13, 1999
DHSS - Rita Manno or Marilyn Riley
ATSDR - Mike Groutt
TRENTON - The New Jersey Department of Health and Senior Services, in cooperation with the federal Agency for Toxic Substances and Disease Registry (ATSDR), today released an update on the epidemiologic study of elevated childhood cancer in Dover Township. However, the report warns that no conclusions can be drawn until the full study is completed next year.
The full epidemiologic study will assess whether any of a wide range of potential cancer risk factors is associated with an increased risk of leukemia, or brain and nervous system cancers in Dover Township children. The final report next year will include important data on parents' exposures to chemicals in the workplace, the nearness of homes to hazardous sites and families' past exposures to air pollution and drinking water sources. Today's report is a preliminary analysis of some of the potential risk factors being studied, such as family medical history, dietary factors, tobacco smoke exposures and others.
"Conducting a scientific study like this is a lengthy, detailed process. And it would not have been possible without the cooperation of the many parents who agreed to participate," said Senior Assistant Commissioner James Blumenstock. "We're pleased that we can now share some preliminary observations with the community.
"However, it's far too early to try to draw any conclusions from this report," Blumenstock added. "We won't know the full meaning of this information until we've analyzed all the study findings, including data on people's environmental and occupational exposures."
The study compares "case" families, who are families of children with cancer, and "control" families, whose children do not have cancer, to see how the various risk factors examined differed. About 150 variables were analyzed and for most factors studied, there were no significant differences. The report discusses some of the ways in which the cases and controls appear to be similar or different.
For some of the variables studied, the report observed the same associations between a particular risk factor and childhood cancer as published in other studies. For example, in Dover Township, as in some other studies, mother's use of prenatal vitamins was less common in leukemia case families than controls, and child's use of electric blankets was more common in leukemia cases. On the other hand, reported consumption of hot dogs, bacon and other cured meats was less common in the township's cancer case families, the report observed. Some published studies have suggested that eating cured meats could increase the risk of childhood cancer, especially brain cancer.
One of the observed differences between cases and controls relates to self-reported tap water consumption. Study investigators asked families how many glasses of tap water the child drank and how much the mother drank while pregnant. The report found that, while they were pregnant, mothers in leukemia case families were more likely to recall above-average tap water consumption (four or more glasses a day) than were mothers in control families. This difference was not seen for nervous system cancer.
It is important to note that, as a preliminary analysis, the report doesn't examine each family's tap water source, length of time the water source was used, or location of the family residence. For example, families could have been living in other towns or outside New Jersey during part of the study period. Also, even while living in Dover Township, families could have been drinking either private well water or water from the community water supply.
"This finding really must be viewed in light of the full report next year," Blumenstock said. He noted that federal ATSDR and the Environmental and Occupational Health Sciences Institute of the University of Medicine and Dentistry of New Jersey are now using complex computer modeling to assist the department in assessing people's exposures to drinking water and air pollution sources in the Dover Township area. Those analyses will be released in the final study report.
"The most important thing the citizens of Toms River need to know is that the state has conducted the most comprehensive examination of their water supply ever done in the state, and possibly the nation, over the last three years," Blumenstock said. "The testing has gone well beyond state and federal drinking water requirements, and as a result the community can be assured of having safe drinking water."
After three years of testing, the department last month released a report on water quality in the United Water Toms River system. The report determined that, in most respects, the water system appears typical of groundwater-based community water supplies in southern New Jersey. When a previously unidentified contaminant - styrene-acrylonitrile trimer - was found in certain water system supply wells in 1996, prompt action was taken to remove the wells from service and install special treatment systems at the Parkway well field. The trimer, a by-product of plastics manufacturing, is linked to the Reich Farm Superfund site.
As part of the overall epidemiologic study, investigators interviewed the parents of 199 children, including 40 with cancer. Investigators asked participants to recall their habits and activities as far back as the early 1960s in some cases. To gather data on township children who may have moved away, investigators analyzed 528 birth records, including those of 48 children with cancer.
The epidemiologic study was developed in response to the community's cancer concerns. Between 1979 and 1995, 90 Dover Township children were diagnosed with cancer; statistically only 67 cases were expected. Elevated rates were seen in leukemia, and brain and nervous system cancers, which are the focus of the study.
The study is part of a joint federal and state cancer investigation that began in March 1996. The multi-million dollar effort has already yielded several reports. In 1997, the department released an analysis of childhood cancer using updated state Cancer Registry data. Last month, the department and ATSDR released for public comment a report on the township's community water supply. And in August, two health assessments were released on the Dover Township Municipal Landfill and the Reich Farm Superfund Site. A third health assessment of the Ciba-Geigy site will be released next month.
Two separate panels of experts have provided scientific oversight of the epidemiologic study. The department convened an independent panel of epidemiologists and cancer experts from universities, medical centers and other government agencies. Peer review has also been provided by scientists identified by federal ATSDR. Industry representatives, local officials and the Citizens Action Committee on Childhood Cancer Cluster also provided input on the design of the study.
Copies of the report and a citizen's guide may be obtained by calling the Department of Health and Senior Services at (609) 633-2043, or the department's Toms River field office at (732) 505-4188. The documents are also available on the department's web site, www.state.nj.us/health.