I am Dr. Mary Guinan, Nevada State Health Officer. I have been asked to speak today on the status of the continuing investigation and federal agency roles in the investigation of cancer clusters.
Status of Investigation:
An Expert Panel was convened on February 15, 2001 to guide the next steps of the investigation. The panel made the following recommendations:
1. Expand case-finding efforts. In progress with Navy. Health Division continues to review cases of leukemia, cancer and other bone marrow diseases reported to us. All reports are kept on file. Expansion of search through the Children's Oncology group and California Cancer Registry will proceed when funding becomes available. (Chronic disease epidemiologist, part time pediatric oncologist).
2. Categorize the Acute Lymphocytic Leukemia (ALL) cases by clinically relevant biomarkers. Need services of pediatric oncologist and funding for locating tissue and determining what phenotypic and genetic tests need to be done and identify laboratory to do testing.
3. Identify potential excess environmental exposures unique to the community. A. Test the drinking water of case families whose water supply is from private wells. Health Division is in process of testing. Nevada State Health Division has requested assistance from the Centers for Disease Control and Prevention and the Agency for Toxic Substances and Disease Registry Human. Representatives of these Agencies will be coming to Nevada during the week of April 16th to review next steps on the following issues: B. Collection of blood and urine samples from cases and family members for testing for environmental chemicals, C. Advisability of dust studies from homes of affected families for environmental chemicals, D. Environmental pathways assessment, E. Radiologic assessment of milk produced in Churchill County.
4. Collect and Bank Biologic Samples for Future Study On hold until funding is made available and storage sites located.
5. Determine time course and characteristics of population movement into the Fallon area. This is part of a bigger picture to provide evidence for population mixing theory. Although some efforts have begun, this is much larger research study than state can support. Federal funding should be made available for this research. 6. Maintain Expert Panel. Panel members have agreed to continue in an advisory role.
In addition the State Health Division has:
A. Enhanced access to public information about the ALL cluster and environmental concerns through multiple public community meetings in Fallon, the Health Division website (health2K.state.nv.us) and a dedicated call-in telephone line.
B. Developed with the Division of Mental Health a mental health crises counseling and community assistance initiative. This has received funding from the Nevada Emergency Management Division and the first steps have been implemented.
Lessons Learned From Investigation of Cluster of ALL with Regard to Federal Agencies Role:
1. Investigation of Cancer Clusters: Although hundreds of cancer clusters have been recognized and investigated during the past 30 years by state and local health departments and Federal agencies, little information is available on appropriate scientific methods of study especially with regard to determining causative factors or associated risk factors. Well over 90% of these investigations have found no associated suspect causative factor. No Federal agency wants to expend scarce resources in investigation of cancer clusters that are likely to show nothing. However state (or local) health departments must investigate clusters to ensure that a dangerous environmental agent is not present in the community contributing to the increase in cancer cases.
While several Federal agencies have expertise in some part of cancer cluster investigations, no one agency has a comprehensive mandate. We have identified gaps in information available to states as follows:
1. No repository of information exists on the occurrence of cancer clusters (i.e., surveillance of cancer of clusters) or to record the results of these investigations.
2. Lack of a standard or a "best-practices guidance" for the investigation of cancer clusters.
3. No information to identify characteristics of clusters that might be most productive to investigate.
4. No resources available to state to implement investigations of clusters with the most promise of advancing the science of cancer causation.
Bringing together all the relevant Federal Public Health Agencies (National Cancer Institute, Centers for Disease Control and Prevention, Agency for Toxic Substances and Disease Registry) and Environmental agencies to develop a comprehensive approach to the study of cancer clusters (which would include at minimum the 4 activities listed above) would greatly enhance the speed, efficiency and scientific validity of cluster investigations. A guidance for best practices for investigation of clusters would reassure the community that standards do exist for these investigations and that health departments efforts can be evaluated in comparison to the standard. Recognition of clusters that may be most productive in finding evidence for causation of cancer and providing resources for the appropriate study of such clusters would prevent lost opportunities and maximize the probability of advancing the science of cancer causation.
2. Environmental Factors. The cause or causes of acute lymphocytic leukemia are largely unknown. Theories of causation have focused on two main theories, A. environmental agents such as chemicals or radiation or B. infection with a virus or bacteria that results in genetic damage that eventually causes leukemia. Studies of suspect infectious and environmental agents for the most part have not been fruitful.
What the environmental factors should be monitored by health departments in a systematic way? No consensus exists on the minimum standards for environmental surveillance. It would be of immense value to the states if all the involved Federal agencies could be brought together (perhaps by ASTHO, an organization of state health officials or another non-governmental agency) and come to consensus on what constitutes the minimum standard for environmental surveillance for state health departments.
The Environmental Protection Agency is often in conflict with federal Public Health Agencies on assessment of risks to health of environmental contaminants. This results in a bizarre mixture of conflicting standards for which states are held accountable. EPA should be required to work with federal Public Health agencies to resolve conflicts on interpretation of scientific data before implementing regulations for the states.
In the Churchill County area many environmental agents are present that may constitute a risk for health, including excess arsenic in the drinking water supply. A great deal of information is available about arsenic in the water and steps have been taken by the City of Fallon to reduce the arsenic in the municipal drinking water. However, community concerns have surfaced about other agents in the environment for which we have much less information. These include jet fuel from Naval Air Station, radioactive substances that may resulted from nuclear testing that was done in 1963 about 20 miles away from Fallon (Project Shoal conducted by Department of Energy), pesticides used for insect control and agriculture, chemical pollutants from industries in the area and air contamination with radioactive or chemical debris from the Sierra Army Depot in California which is about 3 miles from the Nevada border. One of the requirements for the explosion or burning of munitions at this depot is that the wind is blowing toward Nevada at a certain speed before the explosions can take place. There has been no monitoring of the contamination of the air that blows into Nevada from the depot. Therefore no data are available on this potential source of environmental contamination. Despite numerous requests the Environmental Protection Agency has not required California to be accountable to Nevada to ensure that toxic substances are not blown into Nevada from the operation of this depot.
Like all states Nevada does not have jurisdiction over private well water used for drinking water, nor does any Federal agency. The safety of drinking water from these wells is unknown. Churchill County has many households whose water supply comes from private wells. How to ensure the safety of drinking water from private wells is a critical issue for all states. Federal agencies may have a role in providing guidance on solutions to this public health issue.
3. Community Mental Health. Recognition of a cancer cluster in a community is associated with increased stress for the community. The need for preventive mental health services must be assessed. The Nevada Health Division and Mental Health Division have partnered to begin a community mental health initiative in Fallon to assess the need for and to provide the necessary mental health services for the affected families and the community at large.
It would be of great value to have a model for providing such services for communities experiencing cancer clusters. The National Institute for Mental Health and other Public Health agencies have a role in providing guidance for determining mental health needs and providing resources for these services during crises.
APPENDIX: Report of the Expert Panel.