title: Concerns over use of glyphosate-based herbicides and risks associated with exposures: a consensus statement.
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.
authors.affiliation: Environmental Health Sciences, Charlottesville, VA, and Adjunct Professor, Carnegie Mellon University, Pittsburg, PA, USA. jpmyers@ehsic.org.|Environmental Health Sciences, 421 Park St, Charlottesville, VA, 22902, USA. jpmyers@ehsic.org.
authors.forename: John Peterson
authors.initials: JP
authors.lastname: Myers
authors.affiliation: Department of Medical and Molecular Genetics, Faculty of Life Sciences and Medicine, King's College London, London, UK.
authors.forename: Michael N
authors.initials: MN
authors.lastname: Antoniou
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, CA, USA.
authors.forename: Bruce
authors.initials: B
authors.lastname: Blumberg
authors.affiliation: The Endocrine Disruption Exchange, Paonia, CO, USA.
authors.forename: Lynn
authors.initials: L
authors.lastname: Carroll
authors.affiliation: The Endocrine Disruption Exchange, Paonia, CO, USA.
authors.forename: Theo
authors.initials: T
authors.lastname: Colborn
authors.affiliation: L. Everett & Associates, Santa Barbara, CA, USA.
authors.forename: Lorne G
authors.initials: LG
authors.lastname: Everett
authors.affiliation: Consumers Union, Yonkers, NY, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Hansen
authors.affiliation: Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Landrigan
authors.affiliation: Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Bruce P
authors.initials: BP
authors.lastname: Lanphear
authors.affiliation: Department of Medical and Molecular Genetics, Faculty of Life Sciences and Medicine, King's College London, London, UK.
authors.forename: Robin
authors.initials: R
authors.lastname: Mesnage
authors.affiliation: Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts - Amherst, Amherst, MA, USA.
authors.forename: Laura N
authors.initials: LN
authors.lastname: Vandenberg
authors.affiliation: Division of Biological Sciences, University of Missouri, Columbia, MO, USA.
authors.forename: Frederick S
authors.initials: FS
authors.lastname: Vom Saal
authors.affiliation: Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, MO, USA.
authors.forename: Wade V
authors.initials: WV
authors.lastname: Welshons
authors.affiliation: Benbrook Consulting Services, 90063 Troy Road, Enterprise, OR, 97828, USA. charlesbenbrook@gmail.com.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Benbrook
mesh_terms: D002273:Carcinogens / Q000633:toxicity*; D032921:Consensus; D004785:Environmental Pollutants / Q000633:toxicity*; D005998:Glycine / Q000031:analogs & derivatives* / Q000633:toxicity; D006540:Herbicides / Q000633:toxicity*; D006801:Humans; D017410:Practice Guidelines as Topic; D018570:Risk Assessment / Q000592:standards; D018675:Toxicity Tests / Q000592:standards; D014481:United States; D000097797:Glyphosate
chemical_list: D002273:Carcinogens; D004785:Environmental Pollutants; D005998:Glycine; D006540:Herbicides; D000097797:Glyphosate