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Staveley JP, Touart LW, Solomon K, Mihaich E, Blankinship A, Ankley G.2016. Endocrine disruption: where have we been, interpretation of data, and lessons learned from Tier 1. PeerJ Preprints4:e2596v1https://doi.org/10.7287/peerj.preprints.2596v1
In response to the requirements of the US EPA’s Endocrine Disruptor Screening Program, Tier 1 assays have been performed with a number of pesticides over the past several years. These assays are designed to be used in concert as a screen for potential interactions with vertebrate estrogen, androgen, and thyroid systems. The results of the 11 assays in the Tier 1 battery are then used, along with other lines of evidence, to determine whether a chemical is endocrine-active and, as a consequence, might be a candidate for Tier 2 testing. An overview of the Tier-1 testing program was presented in Session Two of the Society of Environmental Toxicology and Chemistry (SETAC) North America Focused Topic Meeting: Endocrine Disruption Chemical Testing: Risk Assessment Approaches and Implications (February 4 – 6, 2014). Subsequent presentations discussed the concept of weight-of-evidence (WoE) and assessment of Tier 1 results in a WoE framework. The importance of scientifically credible, transparent approaches for conducting WoE analyses was recognized, and approaches for framing the hypotheses, evaluating the data, assigning weight to different endpoints relative to their diagnostic effectiveness, and assessing confounding factors were presented. In recognition of the cross-species conservation of the hypothalamic-pituitary-gonadal axis among vertebrates, a subset of the Tier-1 in vivo assays may be useful for more rapidly screening chemicals for potential endocrine activity.
This paper is one of a special series of five papers (all submitted as preprints to PeerJ Preprints) titled: "Special Series on Endocrine Disruption: Chemical Testing, Risk Assessment Approaches and Implications'' about the SETAC Focused Topic Meeting held on this topic from 4 – 6 February, 2014 in Raleigh, North Carolina, US. The series presents the knowledge disseminated and the discussions held on: a) the status of the USEPA Endocrine Disruptor Screening Program, b) how data from both EDSP-directed testing and other sources may be interpreted and applied in regulatory settings and c) approaches for moving beyond estrogen, androgen and thyroid pathways to address current challenges and expanding future approaches to EDC testing.