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EPA's evaluation of the carcinogenic potential of glyphosate
Citation:
EPA's evaluation of the carcinogenic potential of glyphosate.
Impact/Purpose:
Glyphosate is a non-selective, phosphonomethyl amino acid herbicide registered to control weeds in various agricultural and non-agricultural settings. Labeled uses of glyphosate include over 100 terrestrial food crops as well as other non-agricultural sites, such as greenhouses, aquatic areas, and residential areas. Use of glyphosate in the United States and globally has increased overtime, particularly with the introduction of glyphosate-resistant crops; however, usage has stabilized in recent years due to the increased number of weed species becoming resistant to glyphosate. Glyphosate is currently undergoing Registration Review, which is a program where all registered pesticides are reviewed at least every 15 years as mandated by the Federal Insecticide, Fungicide, and Rodenticide Act.
Description:
Recently, several international agencies have evaluated the carcinogenic potential of glyphosate. In March 2015, the International Agency for Research on Cancer (IARC), a subdivision of the World Health Organization (WHO), determined that glyphosate was a probable carcinogen (group 2A). Later, in November 2015, the European Food Safety Authority (EFSA) determined that glyphosate was unlikely to pose a carcinogenic hazard to humans. In May 2016, the Joint Food and Agriculture Organization (FAO)/WHO Meeting on Pesticide Residues (JMPR), another subdivision of the WHO, concluded that glyphosate was unlikely to pose a carcinogenic risk to humans from exposure through the diet. Recently, EPA collected and analyzed a substantial amount of data informing the carcinogenic potential of glyphosate and utilized its draft “Framework for Incorporating Human Epidemiological & Incident Data in Health Risk Assessment” to assess the potential carcinogenic hazard. The draft framework provides the foundation for evaluating multiple lines of scientific evidence and includes two key components: Problem formulation and use of the mode of action/adverse outcome pathway (MOA/AOP) frameworks. A comprehensive analysis of data on glyphosate from submitted guideline studies and the open literature was performed. This includes epidemiological, animal carcinogenicity, genotoxicity, metabolism, and mechanistic studies. Guideline studies were collected for consideration from the toxicological databases for glyphosate and glyphosate salts. A fit-for-purpose systematic review was executed to obtain relevant and appropriate open literature studies with the potential to inform the human carcinogenic potential of glyphosate. Furthermore, the list of studies obtained from the toxicological databases and systematic review was cross-referenced with recent internal reviews, review articles from the open literature, and international agency evaluations (i.e., IARC, EFSA, JMPR). Available data from epidemiological, animal carcinogenicity, and genotoxicity studies were reviewed and evaluated for study quality and results to inform the human carcinogenic potential of glyphosate. Additionally, as described in the draft “Framework for Incorporating Human Epidemiological & Incident Data in Health Risk Assessment,” the multiple lines of evidence were integrated in a weight-of-evidence analysis using the modified Bradford Hill Criteria considering concepts, such as strength, consistency, dose response, temporal concordance, and biological plausibility. The agency will solicit advice from the SAP on the evaluation and interpretation of the available data for each line of evidence and the weight-of-evidence analysis, as well as how the available data inform cancer classification descriptors according to the agency's 2005 Guidelines for Carcinogen Risk Assessment.
URLs/Downloads:
EPA's evaluation of the carcinogenic potential of glyphosateTranscript: FIFRA SAP December 13-16, 2016 (PDF, NA pp, 3145 KB, about PDF)
Draft Human Health and Ecological Risk Assessments for Glyphosat
Revised Glyphosate Issue Paper: Evaluation of Carcinogenic Potential (PDF, NA pp, 2307 KB, about PDF)
Response to the Final Report of the Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (FIFRA SAP) on the Evaluation of the Human Carcinogenic Potential of Glyphosate (PDF, NA pp, 399 KB, about PDF)
Peer Review Plan (PDF, NA pp, 41 KB, about PDF)
FIFRA Scientific Advisory Panel, Meeting Minutes and Final Report, No. 2017-01, EPA's Evaluation of the Carcinogenic Potential of Glyphosate (PDF, NA pp, 906 KB, about PDF)
Glyphosate: Evaluation of Carcinogenic Potential Charge to the FIFRA SAP (PDF, NA pp, 30 KB, about PDF)
Glyphosate Issue Paper: Evaluation of Carcinogenic Potential (PDF, NA pp, 2339 KB, about PDF)