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BCERF held its Spring Regional Cancer and Environment Forum on May 11, 2007, at the Hilton Garden Inn, in Ithaca, NY. BCERF’s own program planning ideas came together with stakeholder requests for this Forum. BCERF had been aiming to address residential exposures to chemicals that may influence cancer risk – a topic that is of increasing concern in the breast cancer research and activist communities – within the context of a Regional Forum. Last year, the American Cancer Society in Endicott, NY, approached us to address trichloroethylene (TCE) exposures through soil vapor intrusion, as several communities in the Southern Tier region of the state are struggling with this problem. We secured national- and state-level speakers on these topics, and were also very fortunate to add a presentation by a highly regarded colleague in the field of breast cancer and environment studies, Dr. Julia Brody of the Silent Spring Institute in Massachusetts. Regional and local updates from the American Cancer Society and the Ithaca Breast Cancer Alliance on educational and activist activity, rounded out this program.
Vol. 12 Issue 2, Spring 2007
BCERF Director/Alexander de Lahunta Chair of Clinical Sciences Dr. Rodney Page welcomed the almost eighty participants. He also took the opportunity to recognize the immeasurable contributions of BCERF’s Associate Director for Translational Research, Dr. Suzanne Snedeker. As the plaque presented to her states, BCERF gratefully recognizes Suzanne’s long-standing leadership and dedication to the sustenance and growth of the program, as well her extraordinary commitment to providing trustworthy answers to complex questions in the field of cancer and environment (see photo).
Dan Lamb, the District Representative of U.S. Congressman Maurice Hinchey, also welcomed the group to Ithaca, and welcomed the opportunity for the community to learn more together about the topic of TCE contamination and its health effects. Congressman Hinchey has been very active on this topic, for example, working to secure federal funds to study cancer rates among 28,000 employees who worked for IBM at its Endicott site. Dan acknowledged the complexities inherent in studying this topic – “like studying a moving target” – and those complexities very much came to light in the presentations that followed.
Cheryl Siegel Scott is an epidemiologist and statistician with the National Center for Environmental Assessment, Washington Office, of the US Environmental Protection Agency (EPA). She and Dr. Weihsueh Chiu, also of the EPA, prepared a background paper, “Trichloroethylene Cancer Epidemiology: A Consideration of Select Issues” for the National Academy of Sciences (NAS) and the paper was published in the September 2006 issue of Environmental Health Perspectives. That paper, which was included in participant’s packets, formed the basis of her talk.
Ms. Scott provided important background on: how does epidemiology as a tool inform inferences about hazard, dose-response and risk assessment, and what are the factors which make an epidemiological study more or less informative (such as study design, statistical power and significance, quality of exposure assessment, and accounting for misclassification, bias, and confounding)?
Ms. Scott then identified the over 50 epidemiologic studies on TCE, categorizing them by type, and, as appropriate, by study population and type of cancer. She then reviewed the studies in terms of their: choice of endpoint (mortality or incidence, and issues of changing incidence classifications over time); exposure assessment approaches (showing diverse approaches across TCE studies, and deficits of early measurement methods), and causal inference approaches. Ms. Scott noted in her presentation that evaluating the body of evidence to date is a work in progress, and cited the NAS recommendations:
In the meantime, the Scott and Chiu paper notes, “epidemiologic studies, when considered as a whole, have associated TCE exposure with excess risk of kidney, liver, lymphohematopoietic, cervical, and prostate cancer,” and subsequent papers “appear to provide further support for several of those conclusions.” (Scott and Chiu, 2006).
Evaluating Soil Vapor Intrusion in New York State (NYS) Soil vapor intrusion of chemical contaminants is an emerging concern; NYS currently has 270 site investigations at various stages, from work plan development to mitigation. However, as Dr. Krista Anders, a public health specialist in the Department of Health's (DOH) Bureau of Environmental Exposure Investigation, told the group, vapor intrusion is not a new phenomenon. Fortunately, sampling equipment and protocols are improving and more precise analytical methods are becoming available.
Dr. Anders, who is the NYS DOH's Assistant Site Coordinator for the IBM Endicott site, as well as being involved in the investigation and remediation of numerous other hazardous waste sites in NYS, began by describing how contaminated soil vapor can enter buildings. Her talk then focused on NYS’s approach for dealing with this widespread problem, including the various types of sampling, and how decision-making is approached once the data is collected. She reviewed the two matrices developed for five compounds of concern: trichloroethene and carbon tetrachloride; and tetrachloroethene 1, 1,1-trichloroethane, and 1,1-dichloroethene.
Dr. Anders also reviewed types of mitigation, activities following mitigation (such as operation, maintenance, and monitoring) and the importance of community outreach. See below for NYS DOH resources on these topics.
Health Statistics Review: Methods, Strengths and Limitations
How does the NYS DOH go about trying to determine whether health outcomes, such as cancer, are occurring at a higher or lower rate in a specific area compared to the rest of the state? Dr. Elizabeth Lewis-Michl, Chief of the Community Exposure Research Section at NYS DOH, addressed participants on this question. Dr. Lewis-Michl’s unit conducts various types of environmental epidemiological studies in response to exposures experienced by NYS residents. The Health Statistics Review (HSR), the set of tools developed for this purpose, cannot tell us why differences in rates exist, nor prove a cause and effect relationship. It can, however, generate hypotheses and may indicate whether a more rigorous study should be considered.
An HSR consists of the following steps:
Dr. Lewis-Michl’s presentation consisted of a review of these methods, their strengths and limitations, providing general information and also the specific example of the Endicott site. Overall strengths to this approach include: NYS has high quality health outcome data available, including statewide data providing a stable comparison population, and the HSR provides a stepping stone to more rigorous analytical epidemiological studies.
In the Endicott Area Investigation, analyses showed significant elevations in two types of cancer, testicular in one study area and kidney cancer in males in the other. But again, the most important limitation to this type of study, Dr. Lewis-Michl emphasized, is that health outcomes, such as the elevated cancer rates, cannot be linked to specific exposures. In an HSR involving soil vapor intrusion, everyone in the study area is considered “exposed.” Individual biomonitoring would be required, as well as additional personal data, for the next level of study. See below for NYS DOH resources on these topics.
We were honored to have BCERF’s close colleague Dr. Julia Brody, the Executive Director of Silent Spring Institute (SSI) and the principal investigator of the Cape Cod Breast Cancer and Environment Study, address the Forum. Dr. Brody’s talk covered two major initiatives of the SSI, as well as a number of current concerns in the field of breast cancer and environment, and strategies for those who’d like to take action.
The SSI’s work focuses on the problem of elevated breast cancer rates on Cape Cod, in Massachusetts. The Cape Cod Breast Cancer and Environment Study, which is carried out by a science-activist partnership, is a hypothesis-generating study of 2,100 women. Geographic Information Systems techniques, as well as environmental and biological sampling of 120 homes, form its unique approach. The study attempts to improve upon existing approaches to exposure assessment, paying attention to mixtures and low levels. For example, an effort to reconstruct historical exposures over a lifetime looked at pesticide exposures via cranberry bogs, tree pest control, and mosquito control.
Results showed weak or inconsistent relationships of breast cancer risk to wide-area pesticide use, and no relationship between nitrate in drinking water and breast cancer risk. Dr. Brody noted, however, that despite the study’s innovations in exposure assessment, major data were lacking, such as: exposures participants may have experienced off Cape Cod; all instances of pesticide use; variation within water supplies; chemical exposures early in life; and, women who were not exposed. The case for an environmental connection remains strong, as three data sets show that the higher breast cancer risk on Cape Cod is not due to an older population, in-migration, mammography use, or established risk factors for breast cancer.
Another groundbreaking effort of the SSI is its Household Exposure Study, which measured 89 chemicals known to be breast carcinogens or endocrine disruptors, in air, dust and urine in 120 households. Thirty of these chemicals were measured for the first time in homes. The results showed levels above guidelines – for all chemicals that have guidelines (28 do not) – and some chemicals, such a phthalates, were found in 100% of homes. Even with a report-back mechanism to communicate with study households (which will be detailed in a forthcoming publication in The American Journal of Public Health), re-testing of 11 households five years later showed most levels remaining high. This demonstrates the persistence of the chemicals and/or how difficult it is for a people to rid their households of chemical contaminants that are so ubiquitous.
Dr. Brody provided an excellent overview of some of the existing data on breast cancer and specific environmental factors, leading up to a discussion of several factors which have emerging evidence of connection to breast cancer risk. These include: polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), organic solvents, and dioxin. Dr. Brody also informed the group of the vast number of chemicals that have been shown to cause breast tumors in laboratory animals, but for which there has been little if any human study. She also provided the important reminder that “no evidence” for a chemical’s connection with cancer risk may simply mean it has not been studied, or was not studied effectively. Dr. Brody concluded with the following action points:
Ms. Carol Lindhorst, the Senior Director of Health Systems and Collaborations for the American Cancer Society Eastern Division, provided an overview of regional breast cancer data, including mortality rates and the decrease in screening utilization. Ms. Lindhorst reported that, for the last three five-year period reported (ending with 1999-2003) cancer mortality rates have gone down in southern NYS, and the percentage of new breast cancer cases diagnosed at an early stage in the same region has gone up. However, she also reported that mammography screening has gone down, with a troubling gap between the insured and the uninsured, as well as by ethnicity, However, the decrease in annual mammography trend has been downward in all ethnicities, income status, and educational levels, from 2000 through 2004. Ms. Lindhorst discussed some likely contributing factors to these trends, such as capacity, access, referrals, and changes in attitudes, and she described American Cancer Society initiatives to reverse these trends.
The mission of the Ithaca Breast Cancer Alliance, IBCA, is “to create and sustain a community of support for people living with and affected by breast and gynecologic cancers in Tompkins and surrounding counties.” Shawn Galbreath, IBCA’s Executive Director, and Jemila Sequeira, Community Outreach Specialist, discussed current activities reaching out to the medically underserved. They described an innovative “lay health advisor” model, which recruits women internal to the target population and trains them to take information back to their communities. Their own version of this will be called Circle of Friends, and include ten “natural” leaders from various local communities. We look forward to the unfolding of this project and the benefits it will bring to Ithaca and surrounding communities.
Selected Resources on TCE and Silent Spring Institute Work on Household Exposures
Compiled by Suzanne Snedeker, Ph.D.
NYS Department of Health Selected Resources on Trichloroethylene (TCE) and Soil Vapor Intrusion
NYS DOH Endicott Area Investigations (links to support documents) http://www.health.state.ny.us/environmental/investigations/broome/
NYS DOH Trichloroethylene (TCE) in Indoor and Outdoor Air, Fact Sheet, February 2005. http://www.health.state.ny.us/environmental/investigations/soil_gas/svi_guidance/fs_tce.htm
NYS DOH Public Health Consultation Health Statistics Review: Cancer and Birth Outcome Analysis, Endicott Area, Town of Union, Broome County, New York, Information Sheet, March 26, 2007. http://www.health.state.ny.us/environmental/investigations/broome/fact_sheet.htm
NYS DOH, What is Exposure? Information sheet, October 2006. http://www.health.state.ny.us/environmental/about/exposure.htm
NYS DOH, Soil Vapor Intrusion, Frequently Asked Questions, May 2004. http://www.health.state.ny.us/environmental/investigations/soil_gas/svi_guidance/docs/svi_faqs.pdf
NYS DOH Endicott Soil Vapor Project, Information Sheet, October 2004. http://www.health.state.ny.us/environmental/investigations/soil_gas/index.htm
NYS DOH, Radon, Frequently Asked Questions, May 2004. http://www.health.state.ny.us/environmental/investigations/soil_gas/svi_guidance/docs/radon_faqs.pdf
Federal Agency Resources on Trichloroethylene (TCE)
EPA Consumer fact sheet on TCE, November 2006. http://www.epa.gov/safewater/contaminants/dw_contamfs/trichlor.html
ATSDR ToxFAQs on TCE , Agency for Toxic Disease Substances Registry, July 2003. http://www.atsdr.cdc.gov/tfacts19.html
Publications in Scientific Journals
Scott and Chiu, Trichloroethylene cancer epidemiology: a consideration of select issues, Environ. Health Perspect., 114(9):1471-1478, 2006. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=16966107
Chiu et al., Key scientific issues in the health risk assessment of trichloroethylene, Environ. Health Perspect;, 114(9):1445-1449, 2006. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=16966103
EPA Issue papers on TCE provided to the National Academy of Sciences in 2005 (Includes papers on pharmacokinetics, interactions, and epidemiology). http://oaspub.epa.gov/eims/xmlreport.display?deid=117502&z_chk=30513
Silent Spring – Cape Cod Breast Cancer and Environment Study
Cape Cod Breast Cancer and Environment Study, home page http://www.silentspring.org/newweb/research/cape.html
Cape Cod Breast Cancer Study, Fact Sheet http://www.silentspring.org/newweb/research/SSIfactsheet.pdf
Household Exposure Study, Fact Sheet http://www.silentspring.org/newweb/research/HES%20Long%20Q&A.pdf
Findings of the Cape Cod Breast Cancer Study – 2006 Report (40 pages) http://library.silentspring.org/publications/pdfs/report_web.pdf
Publications in Scientific Journals
Brody JG et al., Breast cancer risk and drinking water contaminated by wastewater: a case control study, Environ. Health, 5:28, 2006 (11 pages). http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17026759
Brody JG et al., Breast cancer risk and historical exposure to pesticides from wide-area application assessed with GIS, Environ. Health Perspect., 112(8):889-97, 2004. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=15175178
Brody, JG et al., Using GIS and historical records to reconstruct residential exposure to large-scale pesticide application, J Expo Anal Environ Epidemiol, 12(1):64-80, 2002. http://www.nature.com/jea/journal/v12/n1/abs/7500205a.html;jsessionid=3C5A8ECFAA1E6F3E53C71FABF80BB011
Rudel RA et al., Phthalates, alkylphenols, pesticides, polybrominated diphenyl ethers and other endocrine-disrupting compounds in indoor air and dust, Environ. Sci. Technol., 37(20):4543-53, 2003. http://www.silentspring.org/newweb/research/Rudel_ES&T_2003.pdf
Program on Breast Cancer and Environmental Risk Factors
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