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Vandenberg LN, Blumberg B, Antoniou MN, Benbrook CM, Carroll L, Colborn T, Everett LG, Hansen M, Landrigan PJ, Lanphear BP, Mesnage R, vom Saal FS, Welshons WV, Myers JP. Is it time to reassess current safety standards for glyphosate-based herbicides? J Epidemiol Community Health 2017; 71:613-618. [PMID: 28320775 PMCID: PMC5484035 DOI: 10.1136/jech-2016-208463] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 01/25/2017] [Accepted: 01/30/2017] [Indexed: 01/06/2023]
Abstract
Use of glyphosate-based herbicides (GBHs) increased ∼100-fold from 1974 to 2014. Additional increases are expected due to widespread emergence of glyphosate-resistant weeds, increased application of GBHs, and preharvest uses of GBHs as desiccants. Current safety assessments rely heavily on studies conducted over 30 years ago. We have considered information on GBH use, exposures, mechanisms of action, toxicity and epidemiology. Human exposures to glyphosate are rising, and a number of in vitro and in vivo studies challenge the basis for the current safety assessment of glyphosate and GBHs. We conclude that current safety standards for GBHs are outdated and may fail to protect public health or the environment. To improve safety standards, the following are urgently needed: (1) human biomonitoring for glyphosate and its metabolites; (2) prioritisation of glyphosate and GBHs for hazard assessments, including toxicological studies that use state-of-the-art approaches; (3) epidemiological studies, especially of occupationally exposed agricultural workers, pregnant women and their children and (4) evaluations of GBHs in commercially used formulations, recognising that herbicide mixtures likely have effects that are not predicted by studying glyphosate alone.
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Affiliation(s)
- Laura N Vandenberg
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts—Amherst, Amherst, Massachusetts, USA
| | - Bruce Blumberg
- Department of Developmental and Cell Biology, University of California, Irvine, California, USA
| | - Michael N Antoniou
- Department of Medical and Molecular Genetics, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Charles M Benbrook
- University of Newcastle, Newcastle, UK
- Benbrook Consulting Services, Enterprise, Oregon, USA
| | - Lynn Carroll
- TEDX, The Endocrine Disruption Exchange, Paonia, Colorado, USA
| | - Theo Colborn
- TEDX, The Endocrine Disruption Exchange, Paonia, Colorado, USA
| | | | | | - Philip J Landrigan
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Bruce P Lanphear
- Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Robin Mesnage
- Department of Medical and Molecular Genetics, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Frederick S vom Saal
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, USA
| | - Wade V Welshons
- Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, Missouri, USA
| | - John Peterson Myers
- Environmental Health Sciences, Charlottesville, Virginia, USA
- Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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Abstract
This article examines herbicide use in the United States, providing estimates of poundage, land surface covered, distribution, and recent trends based on federal and state figures. Herbicides are by far the most widely used class of pesticide in the US, where 556 million lbs of herbicide active ingredients (AIs) were applied in 1995. Agriculture accounts for the majority of herbicide use, totaling 461 million lbs of AIs in 1995. Over 60% of the poundage of all agricultural herbicides consist of those that are capable of disrupting the endocrine and/or reproductive systems of animals. In addition, at least 17 types of `inert ingredients,' which can equal 90% or more of a pesticide product, have been identified as having potential endocrine-disrupting effects. Atrazine is the predominant herbicide used according to poundage, with 68-73 million lbs of AIs applied in 1995. However, 2,4-D is the most widespread herbicide, covering 78 million acres for agricultural uses alone. Both of these herbicides are reported endocrine disruptors. Acetolactate synthase (ALS) inhibitors, namely the sulfonylureas and imidazolinones, are one of the fastest growing classes of herbicides. Many of these herbicides are 100 times more toxic to select plant species than their predecessors, so they can be applied at rates approximately 100 times lower. Consequently, they can affect plant species at concentration levels so low that no standard chemical protocol can detect them. Due in part to these more potent herbicides, the poundage of herbicides used in the US has decreased since the mid-1980s; however, the available data suggest that the number of treated acres has not significantly declined. A thorough assessment of potential exposure to herbicides by wildlife and humans is limited due to the inaccessibility of production and usage data.
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Affiliation(s)
- Theo Colborn
- Wildlife and Contaminants Program, World Wildlife Fund, Washington, District of Columbia
| | - Polly Short
- Wildlife and Contaminants Program, World Wildlife Fund, Washington, District of Columbia,
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Schug TT, Johnson AF, Birnbaum LS, Colborn T, Guillette LJ, Crews DP, Collins T, Soto AM, Vom Saal FS, McLachlan JA, Sonnenschein C, Heindel JJ. Minireview: Endocrine Disruptors: Past Lessons and Future Directions. Mol Endocrinol 2016; 30:833-47. [PMID: 27477640 PMCID: PMC4965846 DOI: 10.1210/me.2016-1096] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 07/12/2016] [Indexed: 11/19/2022] Open
Abstract
Within the past few decades, the concept of endocrine-disrupting chemicals (EDCs) has risen from a position of total obscurity to become a focus of dialogue, debate, and concern among scientists, physicians, regulators, and the public. The emergence and development of this field of study has not always followed a smooth path, and researchers continue to wrestle with questions about the low-dose effects and nonmonotonic dose responses seen with EDCs, their biological mechanisms of action, the true pervasiveness of these chemicals in our environment and in our bodies, and the extent of their effects on human and wildlife health. This review chronicles the development of the unique, multidisciplinary field of endocrine disruption, highlighting what we have learned about the threat of EDCs and lessons that could be relevant to other fields. It also offers perspectives on the future of the field and opportunities to better protect human health.
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Affiliation(s)
- Thaddeus T Schug
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Anne F Johnson
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Linda S Birnbaum
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Theo Colborn
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Louis J Guillette
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - David P Crews
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Terry Collins
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Ana M Soto
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Frederick S Vom Saal
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - John A McLachlan
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Carlos Sonnenschein
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Jerrold J Heindel
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
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4
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Myers JP, Antoniou MN, Blumberg B, Carroll L, Colborn T, Everett LG, Hansen M, Landrigan PJ, Lanphear BP, Mesnage R, Vandenberg LN, Vom Saal FS, Welshons WV, Benbrook CM. Concerns over use of glyphosate-based herbicides and risks associated with exposures: a consensus statement. Environ Health 2016; 15:19. [PMID: 26883814 PMCID: PMC4756530 DOI: 10.1186/s12940-016-0117-0] [Citation(s) in RCA: 365] [Impact Index Per Article: 45.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 02/06/2016] [Indexed: 05/17/2023]
Abstract
The broad-spectrum herbicide glyphosate (common trade name "Roundup") was first sold to farmers in 1974. Since the late 1970s, the volume of glyphosate-based herbicides (GBHs) applied has increased approximately 100-fold. Further increases in the volume applied are likely due to more and higher rates of application in response to the widespread emergence of glyphosate-resistant weeds and new, pre-harvest, dessicant use patterns. GBHs were developed to replace or reduce reliance on herbicides causing well-documented problems associated with drift and crop damage, slipping efficacy, and human health risks. Initial industry toxicity testing suggested that GBHs posed relatively low risks to non-target species, including mammals, leading regulatory authorities worldwide to set high acceptable exposure limits. To accommodate changes in GBH use patterns associated with genetically engineered, herbicide-tolerant crops, regulators have dramatically increased tolerance levels in maize, oilseed (soybeans and canola), and alfalfa crops and related livestock feeds. Animal and epidemiology studies published in the last decade, however, point to the need for a fresh look at glyphosate toxicity. Furthermore, the World Health Organization's International Agency for Research on Cancer recently concluded that glyphosate is "probably carcinogenic to humans." In response to changing GBH use patterns and advances in scientific understanding of their potential hazards, we have produced a Statement of Concern drawing on emerging science relevant to the safety of GBHs. Our Statement of Concern considers current published literature describing GBH uses, mechanisms of action, toxicity in laboratory animals, and epidemiological studies. It also examines the derivation of current human safety standards. We conclude that: (1) GBHs are the most heavily applied herbicide in the world and usage continues to rise; (2) Worldwide, GBHs often contaminate drinking water sources, precipitation, and air, especially in agricultural regions; (3) The half-life of glyphosate in water and soil is longer than previously recognized; (4) Glyphosate and its metabolites are widely present in the global soybean supply; (5) Human exposures to GBHs are rising; (6) Glyphosate is now authoritatively classified as a probable human carcinogen; (7) Regulatory estimates of tolerable daily intakes for glyphosate in the United States and European Union are based on outdated science. We offer a series of recommendations related to the need for new investments in epidemiological studies, biomonitoring, and toxicology studies that draw on the principles of endocrinology to determine whether the effects of GBHs are due to endocrine disrupting activities. We suggest that common commercial formulations of GBHs should be prioritized for inclusion in government-led toxicology testing programs such as the U.S. National Toxicology Program, as well as for biomonitoring as conducted by the U.S. Centers for Disease Control and Prevention.
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Affiliation(s)
- John Peterson Myers
- Environmental Health Sciences, Charlottesville, VA, and Adjunct Professor, Carnegie Mellon University, Pittsburg, PA, USA.
- Environmental Health Sciences, 421 Park St, Charlottesville, VA, 22902, USA.
| | - Michael N Antoniou
- Department of Medical and Molecular Genetics, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Bruce Blumberg
- Department of Developmental and Cell Biology, University of California, Irvine, CA, USA
| | - Lynn Carroll
- The Endocrine Disruption Exchange, Paonia, CO, USA
| | - Theo Colborn
- The Endocrine Disruption Exchange, Paonia, CO, USA
| | | | | | - Philip J Landrigan
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Bruce P Lanphear
- Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Robin Mesnage
- Department of Medical and Molecular Genetics, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Laura N Vandenberg
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts - Amherst, Amherst, MA, USA
| | | | - Wade V Welshons
- Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, MO, USA
| | - Charles M Benbrook
- Benbrook Consulting Services, 90063 Troy Road, Enterprise, OR, 97828, USA.
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Bolden AL, Kwiatkowski CF, Colborn T. Correction to New Look at BTEX: Are Ambient Levels a Problem? Environ Sci Technol 2015; 49:11984-11989. [PMID: 26394058 DOI: 10.1021/acs.est.5b03462] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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Abstract
Benzene, toluene, ethylbenzene, and xylene (BTEX) are retrieved during fossil fuel extraction and used as solvents in consumer and industrial products, as gasoline additives, and as intermediates in the synthesis of organic compounds for many consumer products. Emissions from the combustion of gasoline and diesel fuels are the largest contributors to atmospheric BTEX concentrations. However, levels indoors (where people spend greater than 83% of their time) can be many times greater than outdoors. In this review we identified epidemiological studies assessing the noncancer health impacts of ambient level BTEX exposure (i.e., nonoccupational) and discussed how the health conditions may be hormonally mediated. Health effects significantly associated with ambient level exposure included sperm abnormalities, reduced fetal growth, cardiovascular disease, respiratory dysfunction, asthma, sensitization to common antigens, and more. Several hormones including estrogens, androgens, glucocorticoids, insulin, and serotonin may be involved in these health outcomes. This analysis suggests that all four chemicals may have endocrine disrupting properties at exposure levels below reference concentrations (i.e., safe levels) issued by the U.S. Environmental Protection Agency. These data should be considered when evaluating the use of BTEX in consumer and industrial products and indicates a need to change how chemicals present at low concentrations are assessed and regulated.
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Affiliation(s)
- Ashley L Bolden
- †The Endocrine Disruption Exchange (TEDX), Paonia, Colorado 81428, United States
| | - Carol F Kwiatkowski
- †The Endocrine Disruption Exchange (TEDX), Paonia, Colorado 81428, United States
- ‡Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Theo Colborn
- †The Endocrine Disruption Exchange (TEDX), Paonia, Colorado 81428, United States
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Vandenberg LN, Colborn T, Hayes TB, Heindel JJ, Jacobs DR, Lee DH, Myers JP, Shioda T, Soto AM, vom Saal FS, Welshons WV, Zoeller RT. Regulatory decisions on endocrine disrupting chemicals should be based on the principles of endocrinology. Reprod Toxicol 2013; 38:1-15. [PMID: 23411111 DOI: 10.1016/j.reprotox.2013.02.002] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/18/2013] [Accepted: 02/01/2013] [Indexed: 02/05/2023]
Abstract
For years, scientists from various disciplines have studied the effects of endocrine disrupting chemicals (EDCs) on the health and wellbeing of humans and wildlife. Some studies have specifically focused on the effects of low doses, i.e. those in the range that are thought to be safe for humans and/or animals. Others have focused on the existence of non-monotonic dose-response curves. These concepts challenge the way that chemical risk assessment is performed for EDCs. Continued discussions have clarified exactly what controversies and challenges remain. We address several of these issues, including why the study and regulation of EDCs should incorporate endocrine principles; what level of consensus there is for low dose effects; challenges to our understanding of non-monotonicity; and whether EDCs have been demonstrated to produce adverse effects. This discussion should result in a better understanding of these issues, and allow for additional dialog on their impact on risk assessment.
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Affiliation(s)
- Laura N Vandenberg
- Center for Regenerative & Developmental Biology, and Department of Biology, Tufts University, Medford, MA, United States.
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Vandenberg LN, Colborn T, Hayes TB, Heindel JJ, Jacobs DR, Lee DH, Shioda T, Soto AM, vom Saal FS, Welshons WV, Zoeller RT, Myers JP. Hormones and endocrine-disrupting chemicals: low-dose effects and nonmonotonic dose responses. Endocr Rev 2012; 33:378-455. [PMID: 22419778 PMCID: PMC3365860 DOI: 10.1210/er.2011-1050] [Citation(s) in RCA: 1939] [Impact Index Per Article: 161.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 02/07/2012] [Indexed: 02/08/2023]
Abstract
For decades, studies of endocrine-disrupting chemicals (EDCs) have challenged traditional concepts in toxicology, in particular the dogma of "the dose makes the poison," because EDCs can have effects at low doses that are not predicted by effects at higher doses. Here, we review two major concepts in EDC studies: low dose and nonmonotonicity. Low-dose effects were defined by the National Toxicology Program as those that occur in the range of human exposures or effects observed at doses below those used for traditional toxicological studies. We review the mechanistic data for low-dose effects and use a weight-of-evidence approach to analyze five examples from the EDC literature. Additionally, we explore nonmonotonic dose-response curves, defined as a nonlinear relationship between dose and effect where the slope of the curve changes sign somewhere within the range of doses examined. We provide a detailed discussion of the mechanisms responsible for generating these phenomena, plus hundreds of examples from the cell culture, animal, and epidemiology literature. We illustrate that nonmonotonic responses and low-dose effects are remarkably common in studies of natural hormones and EDCs. Whether low doses of EDCs influence certain human disorders is no longer conjecture, because epidemiological studies show that environmental exposures to EDCs are associated with human diseases and disabilities. We conclude that when nonmonotonic dose-response curves occur, the effects of low doses cannot be predicted by the effects observed at high doses. Thus, fundamental changes in chemical testing and safety determination are needed to protect human health.
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Affiliation(s)
- Laura N Vandenberg
- Tufts University, Center for Regenerative and Developmental Biology, Department of Biology, 200 Boston Avenue, Suite 4600, Medford, Massachusetts 02155, USA.
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9
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Myers JP, vom Saal FS, Akingbemi BT, Arizono K, Belcher S, Colborn T, Chahoud I, Crain DA, Farabollini F, Guillette LJ, Hassold T, Ho SM, Hunt PA, Iguchi T, Jobling S, Kanno J, Laufer H, Marcus M, McLachlan JA, Nadal A, Oehlmann J, Olea N, Palanza P, Parmigiani S, Rubin BS, Schoenfelder G, Sonnenschein C, Soto AM, Talsness CE, Taylor JA, Vandenberg LN, Vandenbergh JG, Vogel S, Watson CS, Welshons WV, Zoeller RT. Why public health agencies cannot depend on good laboratory practices as a criterion for selecting data: the case of bisphenol A. Environ Health Perspect 2009; 117:309-15. [PMID: 19337501 PMCID: PMC2661896 DOI: 10.1289/ehp.0800173] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Accepted: 10/22/2008] [Indexed: 05/02/2023]
Abstract
BACKGROUND In their safety evaluations of bisphenol A (BPA), the U.S. Food and Drug Administration (FDA) and a counterpart in Europe, the European Food Safety Authority (EFSA), have given special prominence to two industry-funded studies that adhered to standards defined by Good Laboratory Practices (GLP). These same agencies have given much less weight in risk assessments to a large number of independently replicated non-GLP studies conducted with government funding by the leading experts in various fields of science from around the world. OBJECTIVES We reviewed differences between industry-funded GLP studies of BPA conducted by commercial laboratories for regulatory purposes and non-GLP studies conducted in academic and government laboratories to identify hazards and molecular mechanisms mediating adverse effects. We examined the methods and results in the GLP studies that were pivotal in the draft decision of the U.S. FDA declaring BPA safe in relation to findings from studies that were competitive for U.S. National Institutes of Health (NIH) funding, peer-reviewed for publication in leading journals, subject to independent replication, but rejected by the U.S. FDA for regulatory purposes. DISCUSSION Although the U.S. FDA and EFSA have deemed two industry-funded GLP studies of BPA to be superior to hundreds of studies funded by the U.S. NIH and NIH counterparts in other countries, the GLP studies on which the agencies based their decisions have serious conceptual and methodologic flaws. In addition, the U.S. FDA and EFSA have mistakenly assumed that GLP yields valid and reliable scientific findings (i.e., "good science"). Their rationale for favoring GLP studies over hundreds of publically funded studies ignores the central factor in determining the reliability and validity of scientific findings, namely, independent replication, and use of the most appropriate and sensitive state-of-the-art assays, neither of which is an expectation of industry-funded GLP research. CONCLUSIONS Public health decisions should be based on studies using appropriate protocols with appropriate controls and the most sensitive assays, not GLP. Relevant NIH-funded research using state-of-the-art techniques should play a prominent role in safety evaluations of chemicals.
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Abstract
The quality and quantity of the data about the risk posed to humans by individual pesticides vary considerably. Unlike obvious birth defects, most developmental effects cannot be seen at birth or even later in life. Instead, brain and nervous system disturbances are expressed in terms of how an individual behaves and functions, which can vary considerably from birth through adulthood. In this article I challenge the protective value of current pesticide risk assessment strategies in light of the vast numbers of pesticides on the market and the vast number of possible target tissues and end points that often differ depending upon timing of exposure. Using the insecticide chlorpyrifos as a model, I reinforce the need for a new approach to determine the safety of all pesticide classes. Because of the uncertainty that will continue to exist about the safety of pesticides, it is apparent that a new regulatory approach to protect human health is needed.
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Affiliation(s)
- Theo Colborn
- University of Florida, Gainesville, Florida, and TEDX (The Endocrine Disruption Exchange) Inc., Paonia, Colorado 81428, USA.
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11
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Abstract
In this article I explore the possibility that contaminants contribute to the increasing prevalence of attention deficit hyperactivity disorder, autism, and associated neurodevelopmental and behavioral problems in developed countries. I discuss the exquisite sensitivity of the embryo and fetus to thyroid disturbance and provide evidence of human in utero exposure to contaminants that can interfere with the thyroid. Because it may never be possible to link prenatal exposure to a specific chemical with neurodevelopmental damage in humans, I also present alternate models where associations have been made between exposure to specific chemicals or chemical classes and developmental difficulties in laboratory animals, wildlife, and humans.
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Affiliation(s)
- Theo Colborn
- Department of Zoology, University of Florida, Gainesville, Florida, USA.
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12
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Abstract
In 1996, the US Congress directed the Environmental Protection Agency to produce screens and assays to detect estrogenic and other endocrine-disrupting chemicals in food and water. To date, there are none. Years have been wasted in attempts to utilize traditional toxicological approaches to solve the problem, when in retrospect, it is now apparent that the delay in part stems from the reluctance to attack the problem with entirely new approaches. To develop new testing protocols, it is necessary to set aside much of the dogma of toxicology and to begin again with open minds. A few pertinent examples are provided concerning what has been overlooked and what needs to be done. In particular, it is necessary to give close attention to the selection of animal strain and diet, factors that were only loosely controlled historically when one takes into consideration what has been learned in the last decade. Vast numbers of animals have been sacrificed, and more will be sacrificed, in futile attempts to validate assays and to develop safety standards unless knowledge gained over the past decade concerning the sensitivity and complexity of the endocrine system is taken into consideration.
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Affiliation(s)
- Theo Colborn
- World Wildlife Fund, 1250 24th St., Washington, DC 20037, USA.
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Derocher AE, Wolkers H, Colborn T, Schlabach M, Larsen TS, Wiig Ø. Contaminants in Svalbard polar bear samples archived since 1967 and possible population level effects. Sci Total Environ 2003; 301:163-174. [PMID: 12493194 DOI: 10.1016/s0048-9697(02)00303-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Blood plasma samples were collected in 1967 from 32 polar bears (Ursus maritimus) in eastern Svalbard. These samples were stored frozen until 2001 and then analyzed for 33 polychlorinated biphenyls (PCB), two toxaphene congeners, DDTs, chlordanes (CHL), hexachlorobenzene, hexachlorocyclohexanes (HCHs), and polybrominated flame retardants (biphenyls and diphenyl ethers). The 1967 pollutant levels were compared with values from 1993 to 1994 for adult females and adult males to obtain insights into the historical development of pollution in the Norwegian Arctic. Differences in the OC levels measured between 1967 and 1993-1994 ranged from a decrease (PCB 187 and p,p-DDE) to unchanged in both sexes (PCBs 105, 118, 209, and HCH) to an increase in females (PCBs 99, 128, and CHL), to increases in both sexes (PCBs 138, 153, 156, 157, 170, 180, 194, and 206). The maximum change was a nine-fold increase in PCB 157 in adult females. Changes from 1967 to 1993-1994 in contaminant pattern expressed relative to PCB 153 could be explained by a combination of selective metabolism and accumulation of organochlorines in polar bears and temporal changes in the contaminant mixture being transported to the Arctic. Harvest of polar bears in Svalbard ended in 1973 and it appears that most pollutant levels were increasing at the same time that the population was expected to recover from over-harvest. The mean age of adult females in the Svalbard population was similar to other populations where pollution levels are lower but harvest is intense. Females with cubs-of-the-year > or =16 years old are uncommon in the population for unknown reasons. The impacts of contaminants on the Svalbard polar bear population are inconclusive but there are suggestions of contaminant-related population level effects that could have resulted from reproductive impairment of females, lower survival rates of cubs, or increased mortality of reproductive females.
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Abstract
In 1996 the U.S. Congress charged the U.S. Environmental Protection Agency to develop a screening program to test chemicals for their possible estrogenic and other endocrine effects. Shortly thereafter, the Chemical Guidelines Program of the Organisation for Economic Co-operation and Development's (OECD) Environmental Directorate organized a Task Force on Endocrine Disruption Testing and Assessment to coordinate development of internationally harmonized screening and testing protocols. Most of the research devoted to this effort has focused on detecting impaired estrogenicity, androgenicity, and/or steroidogenesis, with little progress toward developing assays to detect chemicals that might interfere with thyroid function. Despite the fact that wildlife biologists have been reporting abnormal thyroid gland development and unusual thyroid hormone (TH) and retinoid ratios in fish and birds since the early 1960s, few studies have demonstrated an association between an environmental contaminant and a particular health end point other than reduced reproductive success at the population level. This article is a review of the literature that specifically examines THs and their role in normal behavior and development in wildlife. It presents several studies that associated changes in the thyroid gland, TH concentrations, and behavior with contaminant exposure. The goal of this article is to provide fodder for the creation of simple screens to detect possible thyroid system agonists and antagonists.
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Affiliation(s)
- Theo Colborn
- Wildlife and Contaminants Program, World Wildlife Fund, 1250 24th Street NW, Washington, DC 20037-9736, USA.
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17
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Colborn T. Impact of Endocrine Disruptors on Brain Development and Behaviour. Proceedings of a conference. 15-20 September 2001, Sicily, Italy. Environ Health Perspect 2002; 110 Suppl 3:335-449. [PMID: 12201292 PMCID: PMC1241180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Abstract
Hypospadias is one of the most common congenital anomalies in the United States, occurring in approximately 1 in 250 newborns or roughly 1 in 125 live male births. It is the result of arrested development of the urethra, foreskin, and ventral surface of the penis where the urethral opening may be anywhere along the shaft, within the scrotum, or in the perineum. The only treatment is surgery. Thus, prevention is imperative. To accomplish this, it is necessary to determine the etiology of hypospadias, the majority of which have been classified as idiopathic. In this paper we briefly describe the normal development of the male external genitalia and review the prevalence, etiology, risk factors, and epidemiology of hypospadias. The majority of hypospadias are believed to have a multifactorial etiology, although a small percentage do result from single gene mutations. Recent findings suggest that some hypospadias could be the result of disrupted gene expression. Discoveries about the antiandrogenic mechanisms of action of some contemporary-use chemicals have provided new knowledge about the organization and development of the urogenital system and may provide additional insight into the etiology of hypospadias and direction for prevention.
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Affiliation(s)
- L S Baskin
- Department of Urology, University of California, San Francisco, California, USA
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19
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Brucker-Davis F, Thayer K, Colborn T. Significant effects of mild endogenous hormonal changes in humans: considerations for low-dose testing. Environ Health Perspect 2001; 109 Suppl 1:21-6. [PMID: 11250802 PMCID: PMC1240539 DOI: 10.1289/ehp.01109s121] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We review the significant and adverse health effects that can occur with relatively small endogenous hormonal changes in pubertal and adult humans. We discuss the effects of hormonal changes that occur within normal physiologic ranges--such as the rising levels of estrogen in peripuberty, which cause growth spurts at low levels and then the fusion of epiphyses at higher levels--and the hormonal variations during the menstrual cycle and their relation to genital phenotypic changes and intercurrent disease evolution. We turn next to adaptive changes in gonadal and other functions during aging, exercise, stress, starvation, and chronic diseases, which can serve as models for the effects of exogenous, hormonally active compounds. Then we review the states of borderline hormonal imbalances such as subclinical (having few or very mild symptoms, if any) hypothyroidism or hyperthyroidism, glucose intolerance, and other endocrine conditions. Finally, we review the deleterious systemic effects of gonadal imbalance. Information stemming from clinical observations leads to the concept of "no threshold" within the endocrine system and thus illustrates the importance of considering low-dose testing for chemicals that interfere with hormonal activity. We also urge attention to more sensitive, less visible end points such as osteoporosis, increased risk for cardiovascular disease, or cognitive changes.
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Affiliation(s)
- F Brucker-Davis
- Service d'Endocrinologie, Diabétologie et Médecine de la Reproduction, Hôpital de l'Archet 1, Nice, France.
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20
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Fournier M, Dégas V, Colborn T, Omara FO, Denizeau F, Potworowski EF, Brousseau P. Immunosuppression in mice fed on diets containing beluga whale blubber from the St Lawrence estuary and the Arctic populations. Toxicol Lett 2000; 112-113:311-7. [PMID: 10720746 DOI: 10.1016/s0378-4274(99)00241-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In order to assess the immunotoxic potential of naturally relevant mixtures of PCBs and other organohalogens, C57Bl/6 mice were fed on diets in which lipids were replaced by blubber of beluga whales from the highly contaminated population of the Saint-Lawrence River, and the less contaminated population from the Arctic. Different ratios of blubber from both sources were mixed in order to allow a dose-response study. Mice were fed for a period of 90 days at the end of which their immunological status was monitored. For general parameters such as body weight, weight of the spleen and the thymus no significant effect of diets were observed. The immunological endpoints such as the blastic transformation of splenocytes and the spleen NK cell activity were not significantly affected by any of the diets compared to control diets. While the different cell subpopulations of peripheral blood and thymus were not affected by the diets, a significant decrease was noted in the CD8+ T cell population in the spleen of mice fed with most of the diets containing beluga blubber. Moreover, the ability of splenic cells to elicit humoral response against sheep red blood cells as well as the potential of peritoneal macrophages to perform phagocytosis were suppressed by all diets containing beluga blubbers. In summary, there was no differences between the groups fed with a blubber diet with low and high organochlorine contamination. However, a clear immunosuppression was demonstrated when these groups were compared to the group fed with beef oil. Despite the fact that we cannot exclude a possible contribution of the fatty acid composition of the beluga blubber to the immunosupression, these results suggest the sensitivity of mouse immune system towards organohalogens, and point out the toxic potential of contaminant mixtures as found in the less contaminated Arctic population.
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Affiliation(s)
- M Fournier
- INRS-Institut Armand-Frappier Santé Humaine. 245 Hymus Boulevard, Point-Claire, Canada.
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21
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DeVito M, Biegel L, Brouwer A, Brown S, Brucker-Davis F, Cheek AO, Christensen R, Colborn T, Cooke P, Crissman J, Crofton K, Doerge D, Gray E, Hauser P, Hurley P, Kohn M, Lazar J, McMaster S, McClain M, McConnell E, Meier C, Miller R, Tietge J, Tyl R. Screening methods for thyroid hormone disruptors. Environ Health Perspect 1999; 107:407-15. [PMID: 10210697 PMCID: PMC1566416 DOI: 10.1289/ehp.99107407] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The U.S. Congress has passed legislation requiring the EPA to implement screening tests for identifying endocrine-disrupting chemicals. A series of workshops was sponsored by the EPA, the Chemical Manufacturers Association, and the World Wildlife Fund; one workshop focused on screens for chemicals that alter thyroid hormone function and homeostasis. Participants at this meeting identified and examined methods to detect alterations in thyroid hormone synthesis, transport, and catabolism. In addition, some methods to detect chemicals that bind to the thyroid hormone receptors acting as either agonists or antagonists were also identified. Screening methods used in mammals as well as other vertebrate classes were examined. There was a general consensus that all known chemicals which interfere with thyroid hormone function and homeostasis act by either inhibiting synthesis, altering serum transport proteins, or by increasing catabolism of thyroid hormones. There are no direct data to support the assertion that certain environmental chemicals bind and activate the thyroid hormone receptors; further research is indicated. In light of this, screening methods should reflect known mechanisms of action. Most methods examined, albeit useful for mechanistic studies, were thought to be too specific and therefore would not be applicable for broad-based screening. Determination of serum thyroid hormone concentrations following chemical exposure in rodents was thought to be a reasonable initial screen. Concurrent histologic evaluation of the thyroid would strengthen this screen. Similar methods in teleosts may be useful as screens, but would require indicators of tissue production of thyroid hormones. The use of tadpole metamorphosis as a screen may also be useful; however, this method requires validation and standardization prior to use as a broad-based screen.
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Affiliation(s)
- M DeVito
- National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
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22
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Abstract
This article examines herbicide use in the United States, providing estimates of poundage, land surface covered, distribution, and recent trends based on federal and state figures. Herbicides are by far the most widely used class of pesticide in the US, where 556 million lbs of herbicide active ingredients (AIs) were applied in 1995. Agriculture accounts for the majority of herbicide use, totaling 461 million lbs of AIs in 1995. Over 60% of the poundage of all agricultural herbicides consist of those that are capable of disrupting the endocrine and/or reproductive systems of animals. In addition, at least 17 types of 'inert ingredients,' which can equal 90% or more of a pesticide product, have been identified as having potential endocrine-disrupting effects. Atrazine is the predominant herbicide used according to poundage, with 68-73 million lbs of AIs applied in 1995. However, 2,4-D is the most widespread herbicide, covering 78 million acres for agricultural uses alone. Both of these herbicides are reported endocrine disruptors. Acetolactate synthase (ALS) inhibitors, namely the sulfonylureas and imidazolinones, are one of the fastest growing classes of herbicides. Many of these herbicides are 100 times more toxic to select plant species than their predecessors, so they can be applied at rates approximately 100 times lower. Consequently, they can affect plant species at concentration levels so low that no standard chemical protocol can detect them. Due in part to these more potent herbicides, the poundage of herbicides used in the US has decreased since the mid-1980s; however, the available data suggest that the number of treated acres has not significantly declined. A thorough assessment of potential exposure to herbicides by wildlife and humans is limited due to the inaccessibility of production and usage data.
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Affiliation(s)
- P Short
- Wildlife and Contaminants Program, World Wildlife Fund, Washington, District of Columbia 20037, USA.
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23
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Johansson ED, Colborn T, Dumanoski D, Myers JP. Our Stolen Future: Are We Threatening Our Fertility, Intelligence and Survival--A Scientific Detective Story. Stud Fam Plann 1998. [DOI: 10.2307/172187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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24
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Abstract
Large quantities of a number of man-made chemicals with the potential to disrupt the developing endocrine and nervous systems in wildlife and humans have been released into the environment. These chemicals are particularly damaging during the embryonic, fetal, and early postnatal periods because they resemble or interfere with the hormones, neurotransmitters, growth factors, and other signaling substances that normally control development. The effects are in many cases irreversible and often are expressed as changes in function rather than as obvious birth defects or clinical diseases. Functional changes pose challenges in documenting the extent of the lesion, especially in the case of neuroendocrinological damage. In the past decade, researchers have added new dimensions to their research strategies in order to compensate for these difficulties. The new approaches reveal more about the extent of the distribution of and exposure to chemicals that interfere with the endocrine and nervous systems and strengthen the links between exposure and damage in developing wildlife and humans. Based on this new knowledge, opportunities abound for extensive multi-disciplinary research involving developmental neurotoxicity.
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Affiliation(s)
- T Colborn
- World Wildlife Fund, Washington, DC 20037, USA.
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25
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Gray LE, Kelce WR, Wiese T, Tyl R, Gaido K, Cook J, Klinefelter G, Desaulniers D, Wilson E, Zacharewski T, Waller C, Foster P, Laskey J, Reel J, Giesy J, Laws S, McLachlan J, Breslin W, Cooper R, Di Giulio R, Johnson R, Purdy R, Mihaich E, Safe S, Colborn T. Endocrine Screening Methods Workshop report: detection of estrogenic and androgenic hormonal and antihormonal activity for chemicals that act via receptor or steroidogenic enzyme mechanisms. Reprod Toxicol 1997; 11:719-50. [PMID: 9311581 DOI: 10.1016/s0890-6238(97)00025-7] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- L E Gray
- National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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26
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Affiliation(s)
- T Colborn
- World Wildlife Fund, NW, Washington, DC 20037, USA. Colborn+%
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Abstract
Information is provided to test the hypothesis that organochlorines introduced into the environment since the early 1940s could threaten the reproductive potential of baleen whales and other cetaceans. Comparisons are made using data on the role of organochlorines in a model system, the Great Lakes region of North America, and in model animals, including humans, pinnipeds, and other wildlife. DDT and PCB are used as model organochlorines with the caveat that there may be thousands of other chemicals in the environment also involved. Improved sensitivity in analytical quantification of synthetic chemicals in biological tissue has been accompanied by an increase in knowledge about biochemical processes that control development and function. The effects described in this review are the result of disrupted gene expression, not damage to the gene. The mechanisms of action of the organochlorines reveal their ability to affect developing organisms at very low concentrations during critical life stages: embryonic, fetal, and early postnatal. Exposure during early development can disrupt the organization of the endocrine, reproductive, immune and nervous systems, effecting irreversible damage that may not be expressed until the individuals reach adulthood. The recent discovery that human sperm count is declining worldwide at a rate of 1 x 10(6) sperm/(mL.yr) suggests common exposure to estrogen-like chemicals during prenatal and early postnatal development. This raises concern for other top predator species that also share the same exposure. Periods of intense feeding followed by long periods of fasting are common among species of baleen whales. This unique strategy places the embryonic and nursing calves in vulnerable positions, because under both situations maternal blood levels are elevated as a result of absorption from food intake or as a result of mobilization as fat is metabolized. Estimates of Toxic Equivalents (TEQs) based on the occurrence of four PCB congeners (118, 183, 153, 180) in sigma PCB reported in whales are highest for St. Lawrence belugas and Faroe Island long-finned pilot whales. This conservative approach reveals that some whale species are within the range of enzyme-induced TEQs at which effects have been associated with adverse health effects in other aquatic species. The epidemiological approach was used for analysis because it was developed to handle multiple exposure scenarios in which direct causal links are virtually impossible to isolate. The analysis includes the tenets of timeorder, strength of association, specificity of cause and effect, consistency, coherence, and predictive performance.
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Affiliation(s)
- T Colborn
- World Wildlife Fund, Washington, DC 20037, USA
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Affiliation(s)
- T Colborn
- World Wildlife Fund, Washington, DC 20037, USA. COLBORN+R%
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Colborn T. Pesticides--how research has succeeded and failed to translate science into policy: endocrinological effects on wildlife. Environ Health Perspect 1995; 103 Suppl 6:81-5. [PMID: 8549498 PMCID: PMC1518898 DOI: 10.1289/ehp.95103s681] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Toxicological research became institutionalized in the United States in response to society's concern about cancer and acute mortality. Driven by risk assessment, research focused on the need for data development and the standardization of testing for regulatory and management purposes in a reactive mode. Although the research community has provided evidence for over 40 years that a number of pesticides and industrial chemicals have disruptive effects on the endocrine system, little attention was given to the evidence when determining the health hazards of synthetic chemicals because of the fixation on cancer. However, recent findings concerning the effects of a number of widespread chemicals on the reproductive success and fertility of wildlife and humans has led to the call for a proactive approach using investigative research (forensic science). Suggestions are presented to modernize the research agenda of public health institutions to meet society's needs to address the problems of exposure to endocrine, nervous, and immune system disruptors.
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Affiliation(s)
- T Colborn
- Wildlife and Contaminants Program, World Wildlife Fund, Washington, DC 20037, USA
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Abstract
This article proposes that genetic and molecular ecotoxicology can play an important role in making policy and risk assessment decisions concerning xenobiotics. It calls for a greater awareness by ecotoxicologists to the effects in wildlife and humans resulting from transgenerational exposure to synthetic chemicals that interfere with gene expression and differentiation. The difficulty of recognizing these effects on the endocrine, immune, and nervous systems in developing embryos is described and suggests why effects of this nature have traditionally not been addressed when determining risk to synthetic chemicals. Specific examples are cited of environmental effects on hormonally responsive tissue in wildlife populations which could be used as models for assessing human exposure to synthetic chemicals. Evidence is presented that the environmental load of synthetic chemicals has reached critical levels at which wildlife and human health are at risk.
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Affiliation(s)
- T Colborn
- World Wildlife Fund, Washington, DC 20037, USA
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Abstract
Large numbers and large quantities of endocrine-disrupting chemicals have been released into the environment since World War II. Many of these chemicals can disturb development of the endocrine system and of the organs that respond to endocrine signals in organisms indirectly exposed during prenatal and/or early postnatal life; effects of exposure during development are permanent and irreversible. The risk to the developing organism can also stem from direct exposure of the offspring after birth or hatching. In addition, transgenerational exposure can result from the exposure of the mother to a chemical at any time throughout her life before producing offspring due to persistence of endocrine-disrupting chemicals in body fat, which is mobilized during egg laying or pregnancy and lactation. Mechanisms underlying the disruption of the development of vital systems, such as the endocrine, reproductive, and immune systems, are discussed with reference to wildlife, laboratory animals, and humans.
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Affiliation(s)
- T Colborn
- W. Alton Jones Foundation, Washington, DC 20037
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Colborn T, vom Saal FS, Soto AM. Developmental effects of endocrine-disrupting chemicals in wildlife and humans. Environ Health Perspect 1993; 101:378-384. [PMID: 8080506 DOI: 10.2307/3431890] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Large numbers and large quantities of endocrine-disrupting chemicals have been released into the environment since World War II. Many of these chemicals can disturb development of the endocrine system and of the organs that respond to endocrine signals in organisms indirectly exposed during prenatal and/or early postnatal life; effects of exposure during development are permanent and irreversible. The risk to the developing organism can also stem from direct exposure of the offspring after birth or hatching. In addition, transgenerational exposure can result from the exposure of the mother to a chemical at any time throughout her life before producing offspring due to persistence of endocrine-disrupting chemicals in body fat, which is mobilized during egg laying or pregnancy and lactation. Mechanisms underlying the disruption of the development of vital systems, such as the endocrine, reproductive, and immune systems, are discussed with reference to wildlife, laboratory animals, and humans.
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Affiliation(s)
- T Colborn
- W. Alton Jones Foundation, Washington, DC 20037
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33
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Affiliation(s)
- J. P. Myers
- W. Alton Jones Foundation, Inc., Charlottesville, VA 22901-5178
| | - T. Colborn
- W. Alton Jones Foundation, Inc., Charlottesville, VA 22901-5178
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Abstract
Historical data are provided to support the hypothesis that organochlorine chemicals introduced into the Great Lakes ecosystem following World War II are the cause of reproductive loss among bald eagles (Haliaeetus leucocephalus) in the basin. This is supported with data on concurrent population fluxes of extrabasin North American bald eagle populations and the European white-tailed sea eagle (Haliaeetus albicillus) where the same chemicals were produced and released. Organochlorine chemicals appear as a unique stress on Great Lakes bald eagle populations when compared with stresses on successful populations of bald eagles continentwide. Shoreline birds bear significantly higher concentrations of these persistent toxics than inland birds. Association between contaminated prey and elevated concentrations of PCBs, DDT, and DDE in Great Lakes bald eagles are presented. A fledging ratio is used to support the hypothesis that maternal prezygotic exposure affects the viability of embryos and chicks. The ratio of the mean number of fledglings per successful territory to the mean number of fledglings per active territory, when the numerator is greater than 1.4, provides an index of exposure to contaminants by parental animals and affected offspring. When the ratio is greater than 2, parental exposure to organochlorine chemicals should be considered. The adverse effects of prezygotic exposure to the same contaminants in other animal species dependent upon Great Lakes fish, and extrabasin bald eagle populations dependent upon contaminated fish, provide consistency to the argument. The mechanism of action of the organochlorine chemicals further strengthens the causal argument indicting DDT, DDE, and PCBs. A strong association between DDT/DDE and bald eagle reproductive success is provided. However, the role of PCBs is not ruled out. Only data for total PCB concentrations in bald eagle tissue are available, and until specific PCB congeners are quantified there will be uncertainty concerning PCB's role in the Great Lakes bald eagle's lack of success.
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Affiliation(s)
- T Colborn
- World Wildlife Fund, Washington, D.C
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Colborn T. Measurement of low levels of molybdenum in the environment by using aquatic insects. Bull Environ Contam Toxicol 1982; 29:422-428. [PMID: 7171853 DOI: 10.1007/bf01605606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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