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Your Environment. Your Health.

Chronic Disease Epidemiology Group

Risk Factors for Chronic Disease

Photo of Sandler, Dale P.
Dale Sandler, Ph.D.
Chief, Epidemiology Branch and Senior Investigator
Tel 984-287-3711
Fax 301-480-3290
P.O. Box 12233
Mail Drop A3-05
Durham, N.C. 27709

Research Summary

Chronic Disease Epidemiology Group Image

The Chronic Disease Epidemiology Group studies a wide range of chronic diseases and conditions. Work takes advantage of large prospective cohort studies developed to study the impact of environmental and lifestyle exposures on population health. These cohorts allow for both hypothesis driven and opportunistic research, enabling the group to explore outcomes not envisioned when the cohorts were designed, and foster translational and cross-disciplinary research.

The group includes three Staff Scientists and an Associate Investigator working under an Interagency Personnel Act Agreement who serve as lead investigators for research involving the Epidemiology Branch cohorts and conduct related research.

  • Richard Kwok Ph.D. is Staff Scientist and Co-PI of the Gulf Long-term Follow-up Study (GuLF STUDY). He conducts research on disaster-related mental health, exposure assessment, and health effects of oil spills.
  • Lawrence Engel, Ph.D., Associate Professor of Epidemiology at the University of North Carolina School of Public Health, serves, along with Sandler and Kwok, as Co-PI of the GuLF STUDY.
  • Katie O'Brien, Ph.D., is Staff Scientist and Lead Investigator for the Sister Study and conducts research on biomarkers of environmental exposures and how these interact with genetic factors to affect risk for breast, ovarian, and uterine cancer.
  • Christine Park, Ph.D. is Staff Scientist for the Agricultural Health Study (AHS) and conducts research on autoimmune diseases.

The Chronic Disease Epidemiology Group is headed by Dale Sandler, Ph.D., who also is Chief of the Epidemiology Branch in the Division of Intramural Research at NIEHS. Sandler is adjunct professor of Epidemiology at the University of North Carolina at Chapel Hill, past editor of the journal, Epidemiology, past editorial board member for the American Journal of Epidemiology, and a past president of the American College of Epidemiology. Sandler has authored more than 340 scientific articles in peer-reviewed journals. She received an M.P.H. from Yale University in 1975 and a Ph.D. in Epidemiology from The Johns Hopkins University in 1979. In 2013, she won the Nathan Davis Award for Outstanding Government Service from the American Medical Association.

Sandler’s research takes advantage of large prospective cohort studies that she developed. Interests include health effects of pesticides and oil spill related exposures and the influence of environmental and lifestyle exposures across the lifespan in relation to risk for breast cancer and other health outcomes in women. 

In 1990, Sandler joined forces with the National Cancer Institute to develop the Agricultural Health Study, a prospective study of licensed pesticide applicators and their spouses. Sandler expanded the focus to include non-cancer outcomes plausibly linked to agricultural exposures. Her group has linked pesticides and other agricultural exposures to risk for Parkinson’s disease, respiratory disease, diabetes, thyroid disease, End Stage Renal Disease (ESRD), and rheumatoid arthritis.

Sandler initiated and is Principal Investigator of The Sister Study, a prospective cohort of over 50,000 women with enhanced risk for breast cancer due to having had a sister who was diagnosed with the disease. Sandler’s group studies early life, reproductive, lifestyle, environmental and genetic factors related to breast cancer risk. The richness of this resource allows the group to consider the impact of timing of exposures in relation to risk. The group also studies genetic factors (e.g. gene variation, telomere length, methylation) in relation to breast cancer risk through collaborations with other NIEHS groups and participation in large consortia seeking to identify genetic risk and prognostic factors for breast and other cancers through genome-wide association studies (GWAS) and other approaches.

The Sister Study now follows breast cancer survivors enrolled in a related study, The Two Sister Study, a family-based study of genetic and environmental risk factors for young onset breast cancer directed by Clarice Weinberg, Ph.D. in the NIEHS Biostatistics and Computational Biology Branch. The young-onset sisters added though this effort, together with newly diagnosed cases over the course of the Sister Study, provide a unique survivor cohort for studies of the genetic and environmental factors that contribute along with treatment to healthy survival following breast cancer diagnosis. Through collaboration with the CDC, Sandler’s group also addresses factors related to breast cancer survivorship.

With Richard Kwok, Ph.D. and Lawrence Engel, Ph.D. Sandler initiated the GuLF STUDY, a prospective cohort study of persons who were involved in some aspect of oil spill response and clean-up following the April 2010 Deepwater Horizon disaster in the Gulf of Mexico. Nearly 33,000 persons enrolled between March 2011 and March 2013 by completing a comprehensive telephone interview about their oil spill work experience, current physical and mental health, and health at time of the oil spill. A subgroup of 11,200 Gulf state residents completed home visits that included additional questionnaires, collection of biological and environmental samples, and measurement of lung function and blood pressure. Follow-up includes record linkage and telephone interviews, as well as a clinic exam with assessment of pulmonary and neurologic function completed by participants living within 60 miles of a study clinic. Outcomes of interest include respiratory and neurological function, respiratory, cardiovascular, metabolic, and mental health. 


  • The Agricultural Health Study (AHS):
    Study website: .

    The AHS explores a wide range of health outcomes among licensed pesticide applicators, their spouses and children potentially exposed to pesticides and other agricultural hazards. The study includes nearly 5,000 commercial pesticide applicators from Iowa, 52,000 private pesticide applicators, mostly farmers, from Iowa and North Carolina and 32,000 spouses of private applicators who have been followed since enrollment in 1993–1997.
    Related NIEHS-sponsored AHS studies include:

    • Farming and Movement Evaluation (FAME) Study - A nested case-control study of the relationship between Parkinson's disease and exposure to pesticides, other neurotoxicants and soil pathogens, funded by the Epidemiology Branch and an extramural grant to Carolyn Tanner, Ph.D. at the Parkinson’s Institute. This study, led by Freya Kamel, also examines the connection between Parkinson’s disease and lifestyle factors and polymorphisms in genes involved in xenobiotic metabolism, dopaminergic neurotransmission or xenobiotic-specific membrane transport.
      • AHS Neurobehavioral Study - A cross-sectional study involving tests of neurobehavioral and neurological function conducted with 800 AHS cohort members selected based on history of use of organophosphate pesticides. The study included questionnaires, clinical measures, and collection of biological samples. Funded in part by the NIEHS Epidemiology Branch, much of the work was carried out through an extramural grant to Frederic Gerr, Ph.D., University of Iowa.
      • AHS Lung Health Study - An in-depth investigation of the impact of genetic factors, pesticides and other life-long agricultural exposures on pulmonary function and respiratory health led by Stephanie London and funded through the American Recovery and Reinvestment Act of 2009 (ARRA). This on-going study includes in-home assessment of pulmonary function and collection of dust samples, biologic samples, and additional questionnaire data.

      • GuLF STUDY:
        Study website:

        The Gulf Long-term Follow-up Study (GuLF STUDY) is investigating potential health effects associated with response and clean-up activities following the 2010 Deepwater Horizon disaster in the Gulf of Mexico. Nearly 33,000 persons who performed oil-spill related work or received safety training but did not participate in the oil spill response enrolled in the study between March 2011 and March 2013 by completing comprehensive telephone questionnaires about work experiences and health. Nearly 11,200 persons from Gulf states completed home exams that included additional questionnaires, collection of biological and environmental samples, and measurement of lung function and blood pressure.

      • The Sister Study:
        Study website:
        The Sister Study is prospectively examining environmental and familial risk factors for breast cancer and other diseases in a cohort of 50,000 sisters of women who have had breast cancer. Breast cancer-free participants aged 35-74 from across the U.S. and Puerto Rico who had a sister diagnosed with breast cancer enrolled in 2003-2009 by providing questionnaire data about life-time exposures and completing home exams including collection of biological samples. Participants are being followed with brief annual updates and periodic comprehensive questionnaires. As of August 2015, more than 2,800 breast cancers were diagnosed in the cohort.

      Selected Publications

      1. Kim S, Taylor JA, Milne GL, Sandler DP. Association between Urinary Prostaglandin E2 Metabolite and Breast Cancer Risk: A Prospective, Case-Cohort Study of Postmenopausal Women. Cancer prevention research (Philadelphia, Pa.) 2013 6(6):511-518. [Abstract]
      2. Goldner WS, Sandler DP, Yu F, Shostrom V, Hoppin JA, Kamel F, LeVan TD. Hypothyroidism and pesticide exposure among male private pesticide applicators in the Agricultural Health Study. J Occup Environ Med 2013;55:1171-1178. PMID: 24064777. PMCID: PMC3785845. [Abstract] 
      3. Parks CG, D'Aloisio AA, DeRoo LA, Huiber K, Rider LG, Miller FW, Sandler DP. Childhood socioeconomic factors and perinatal characteristics influence development of rheumatoid arthritis in adulthood. Ann Rheum Dis 2013; 72:350-356. E-pub 2012 May 12. PMID: 22586176. PMCID: PMC5029277 [Abstract] 
      4. Xu Z, Bolick SCE, DeRoo LA, Weinberg CR, Sandler DP, Taylor JA. DNA methylation in blood is associated with breast cancer: A study in prospective samples from the Sister Study. Journal of the National Cancer Institute 105(10):694-700, 2013. [Abstract] 
      5. Nichols HB, DeRoo LA, Scharf DR, Sandler DP. Risk-benefit profiles of women using tamoxifen for chemoprevention. Journal of the National Cancer Institute 2014 107(1):dju354-. [Abstract] 
      6. Starling AP, Umbach DM, Kamel F, Long S, Sandler DP, Hoppin JA. Pesticide use and incident diabetes among wives of farmers in the Agricultural Health Study. Occup Environ Med 2014; 71:629-235. E-pub 2014 Apr 12. PMID: 24727735. PMCID: PMC4127367. [Abstract] 
      7. Ekenga CC, Parks CG, D’Aloisio AA, DeRoo LA, Sandler DP. Breast cancer risk after occupational solvent exposure: the influence of timing and setting. Cancer Res 2014;74:3076-3083. E-pub 1 Jun 2014. PMID: 24879566. PMCID: PMC4059370. [Abstract] 
      8. Nichols HB, Baird DD, Stanczyk FZ, Steiner AZ, Troester MA, Whitworth KW, Sandler DP. Anti-Müllerian hormone concentrations in premenopausal women and breast cancer risk. Cancer prevention research (Philadelphia, Pa.) 8(6):528-534, 2015. [Abstract] 
      9. Ekenga CC, Parks CG, Sandler DP. A prospective study of occupational physical activity and breast cancer risk. Cancer causes & control: CCC 2015 26(12):1779-1789. [Abstract] 
      10. Reding KW, Young MT, Szpiro AA, Han CJ, DeRoo LA, Weinberg CR, Kaufman JD, Sandler DP. Breast Cancer Risk in Relation to Ambient Air Pollution Exposure at Residences in the Sister Study Cohort. Cancer epidemiology, biomarkers & prevention: a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 2015 24(12):1907-1909. [Abstract] 
      11. White AJ, Nichols HB, Bradshaw P, Sandler DP. Overall and central adiposity and breast cancer by menopausal status and hormone receptor subtype in the Sister Study. Cancer 2015; 121:3700-3708.E-pub 20 Jul 2015.  PMID: 26193782. PMCID: PMC4592412. [Abstract] 
      12. Kim S, Shore DL, Wilson LE, Sanniez EI, Kim JH, Taylor JA, Sandler DP. Lifetime use of nonsteroidal anti-inflammatory drugs and breast cancer risk: results from a prospective study of women with a sister with breast cancer. Breast cancer research: BCR 2015 15(960):-. [Abstract] 
      13. Lebov JF, Engel LS, Richardson D, Hogan SL, Hoppin JA, Sandler DP. Pesticide use and risk of end-stage renal disease among licensed pesticide applicators in the Agricultural Health Study. Occupational and environmental medicine 2016 73(1):3-12. [Abstract] 
      14. Kwok RK, Engel LS, Miller AK, Blair A, Curry MD, Jackson II WB, Stewart PA, Stenzel MR, Birnbaum LS, Sandler DP, GuLF STUDY Research Team. (2017) The GuLF STUDY: a prospective study of persons involved in the Deepwater Horizon oil spill response and clean-up. Environmental Health Perspectives. 125:570-578. doi: 10.1289/EHP715 
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