Environmental Health Perspectives Volume 108, Supplement 5, October 2000
Women's Health and the Environment in the 21st Century
Kenneth Olden1 and Retha R. Newbold2
1Office of the Director, 2Laboratory of Toxicology, Environmental Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
Abstract
For many years, the National Institute of Environmental Health Sciences has been a leader in studying the role of environmental factors in the causation of diseases that are particularly prevalent or unique to women. As we enter the next millennium, we face exciting new possibilities in broadening our understanding of how the environment impacts women's health. Sophisticated new technology and scientific information are now available to help us more precisely define environmental contributions to disease. Moreover, further development of our information base in environmental health sciences will usher in a new era of informed preventive care for women of all ages. The hallmark of this new era will be our ability to finally address the etiology and prevention of disease, rather than simply focusing on treatment and management of human illness.
Key words: autoimmune diseases, breast cancer, endocrine disrupters, endometriosis, environmental estrogens, environmental exposures, gender differences, health disparity, osteoporosis, uterine leiomyoma, women's health. --
Environ Health Perspect 108(suppl 5):767-768 (2000).
http://ehpnet1.niehs.nih.gov/docs/2000/suppl-5/767-768olden/abstract.html
This article is based on a presentation at the conference on Women's Health and the Environment: The Next Century--Advances in Uterine Leiomyoma Research held 7-8 October 1999 in Research Triangle Park, North Carolina, USA.
Address correspondence to R.R. Newbold, NIEHS, MD E4-02, PO Box 12233, Research Triangle Park, NC 27709 USA. Telephone: (919) 541-0738. Fax: (919) 541-4634. E-mail: newbold1@niehs.nih.gov
Received 23 February 2000; accepted 13 April 2000.
Women's health issues are currently receiving a renewed focus of research interest nationwide that is especially important in light of the lack of historical information on conditions that are more prevalent in women or manifest themselves differently in females compared to males. The National Institute of Environmental Health Sciences (NIEHS) has a longstanding record of researching the impact of the environment on women's health. Investigators in both the intramural and extramural programs have focused on how environmental factors interact with a woman's individual genetic susceptibilities to affect her health over her lifetime. These juxtaposed factors may affect not only the duration, but also the quality of life. For women, this is especially important, as they live longer than men and are more likely to be affected by chronic disorders and disabilities that increase with age. Although we have made substantial progress, much basic and applied research remains to be done to more fully understand the role of the environment in disease causation, since environmentally associated diseases are so complex and multifactorial.
Part of the complexity is because people differ, often significantly, in their susceptibility to environmental agents (1-3). Gender and ethnic differences in susceptibility to environmental factors may be related to genetic polymorphisms and mutations. For example, research identifying specific genes (BRAC1, BRAC2) that are reliable predictors of breast cancer susceptibility (4,5) has thus far produced enormous information that is beneficial for both early detection and diagnosis. Other genes or combinations of genes are being investigated, with the plan to study them in cellular or animal models to identify mechanisms and associated diseases. In addition, NIEHS has initiated a major research effort to collect susceptibility genes for large-scale studies and to determine how these genes vary from person to person. This research effort, called the Environmental Genome Project (EGP), is a multidisciplinary, collaborative effort with the goal of identifying variations in genes that, triggered by substances in the environment, predispose people to diseases and disorders. Detailed information on the EGP is available on the Internet (6). Information obtained from this project will greatly enhance our knowledge of the individual genetic contribution to susceptibility to environmental factors.
An additional complexity is that age and the timing of exposures to environmental agents can have a profound effect on individual susceptibility. For example, the well-known adverse effects of the antimiscarriage drug diethylstilbestrol (DES) and subsequent development of vaginal cancer in the daughters who were exposed during in utero development [see Herbst and Bern (7), for review)], and the perinatal DES-exposed experimental animal model (8) point to critical stages of susceptibility. In fact, the hypothesis that exposure to environmental agents early in life is of greater health significance than adult exposure is currently being investigated by NIEHS researchers studying the effects of endocrine-disrupting chemicals during development and the importance of timing of exposure in cancer risk (7). Yet another aspect of timing that complicates environmental health research is that the appearance of disease often occurs much later than the causative exposure. This was the case with DES, and this delay makes identifying the contributing factor(s) difficult but challenging, requiring both laboratory- and human population-based studies.
Another challenge to environmental health research is the fact that environmental contributors to disease are multifactorial and not limited to one specific agent. As our concept of potential environmental factors continues to expand, we now recognize that adverse environmental conditions that may contribute to disease range from water, air, and soil pollution to contamination of the workplace. Occupational hazards include, but are not limited to, exposure to chemicals, pesticides, asbestos, metals, and tobacco smoke. Community and home factors such as exposure to radon, lead-based paints, food, cosmetics, and pharmaceuticals may all affect women's health. The mechanisms by which these factors interact and disrupt women's endocrine, reproductive, central nervous, and immune systems and cause specific diseases such as osteoporosis, endometriosis, uterine fibroids, autoimmune disease, and cancer are only beginning to be understood. NIEHS continues to meet the challenge of environmental health research with strong programs in basic science, risk assessment, and epidemiology.
NIEHS has a long history of accomplishments in conducting and supporting research in women's health issues and the probability that there are significant environmental components that impact a woman's risk for developing specific diseases. Some of the areas in which important contributions have been made are breast cancer, osteoporosis, autoimmune disease, lactation, environmental estrogens and endocrine-disrupting substances, DES and developmental exposures, infertility/subfertility, and ovarian toxicity. In response to growing public concern for the effects of environmental exposures on human fertility, pregnancy, and the health of children, NIEHS recently established the National Toxicology Program Center for the Evaluation of Risks to Human Reproduction. The Center will provide the public, government agencies, industry, and the scientific community with scientifically sound evaluations of the scientific literature on a chemical or chemical mixture. The Center will issue reports that will evaluate scientific evidence that an exposure poses a hazard to reproduction, development, or children's health. The reports will be written in lay terms and made available to the public through the Center's website (9) and the journal Environmental Health Perspectives.
NIEHS continues its research commitment to women's health issues by sponsoring the current conference "Advances in Uterine Leiomyoma Research" to focus attention on a disease that affects a majority of women sometime in their adult life. Although incidences of uterine leiomyomas (fibroids) have been estimated to be as high as 80%, little is known of the etiology or environmental factors that contribute to the disease. For the first time, this conference brings together information from population-based studies, experimental animal models, and basic molecular studies, with the expectation of better understanding this disease.
In summary, the role of the environment has been recognized as an important determinant in women's health and disease over the life span. Although environmental health research is complicated by a number of issues, recent advances in genetic and molecular biology have given us tools to strengthen our ability to study environmentally related diseases and to more precisely define the environmental contribution to disease. This enhanced environmental health science information base will usher in a new era of informed preventative care for women. The hallmark of this era will be our ability to address the cause of disease, rather than just managing human illness. The goal for the next century is for women to enjoy lives that are not only longer, but also substantially healthier.
REFERENCES AND NOTES
1. Portier CJ, Bell DA. Genetic susceptibility: significance in risk assessment. Toxicol Lett 103:185-189 (1998).
2. Barrett JC, Vainio H, Peakall D, Goldstein BD. 12th Meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals: susceptibility to environmental hazards. Environ Health Perspect 105:699-737 (1997).
3. Paules RS, Tennant RW, Barrett JC, Lucier GW. Bringing genomics into risk analysis: the promises and problems. Risk Policy Rep 17:30-33 (1999).
4. Futreal PA, Liu QY, Shattuckeidens D, Cochran C, Harshman K, Tavtigian S, Bennett LM, Haugenstrano A, Swensen J, Miki Y, et al. BRCA1 mutations in primary breast and ovarian carcinomas. Science 266:120-122 (1994).
5. McAllister KA, HaugenStrano A, Hagevik S, Brownlee HA, Collins NK, Futreal PA, Bennett LM, Wiseman RW. Characterization of the rat and mouse homologues of the BRCA2 breast cancer susceptibility gene. Cancer Res 57(15):3121-3125 (1997).
6. National Institute of Environmental Health Sciences. Available: http://www.niehs.nih.gov [updated 16 August 2000].
7. Herbst AL, Bern HA. Developmental Effects of Diethylstilbestrol (DES) in Pregnancy. New York:Thieme-Stratton, 1981.
8. Newbold RR. Cellular and molecular effects of developmental exposure to diethylstilbestrol: implications for other environmental estrogens. Environ Health Perspect 103:83-87 (1995).
9. National Toxicology Program. Center for the Evaluation of Risks to Human Reproduction. Available: http://www.cerhr.niehs.nih.gov [updated 18 July 2000].
Last Updated: October 2, 2000
