title: Application of an integrated testing strategy to the U.S. EPA endocrine disruptor screening program.
abstract: New approaches to generating and evaluating toxicity data for chemicals are needed to cope with the ever-increasing demands of new programs. One such approach involves the use of an integrated testing and evaluation strategy based on the specific properties and activities of a chemical. Such an integrated strategy, whether applied to existing or future programs, can promote efficient use of resources and save animals. We demonstrate the utility of such a strategy by applying it to the current U.S. Environmental Protection Agency Endocrine Disruptor Screening Program (EDSP). Launched in October 2009, the EDSP utilizes a two-tiered approach, whereby each tier requires a battery of animal-intensive and expensive tests. Tier 1 consists of five in vitro and six in vivo assays that are intended to determine a chemical's potential to interact with the estrogen (E), androgen (A), or thyroid (T) hormone pathways. Tier 2 is proposed to consist of multigenerational reproductive and developmental toxicity tests in several species and is intended to determine whether a chemical can cause adverse effects resulting from E, A, or T modulation. In contrast to the existing EDSP structure, we show, using the pesticide atrazine as an example, that a multilevel testing framework combined with an integrated evaluation process would significantly increase efficiency by minimizing testing.
authors.affiliation: Regulatory Testing Division, People for the Ethical Treatment of Animals, Norfolk, Virginia 23510, USA.
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Willett
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Bishop
authors.forename: Kristie M
authors.initials: KM
authors.lastname: Sullivan
mesh_terms: D023401:Animal Use Alternatives; D000818:Animals; D052244:Endocrine Disruptors / Q000633:toxicity*; D004703:Endocrine System / Q000187:drug effects*; D004784:Environmental Monitoring / Q000191:economics / Q000379:methods* / Q000592:standards; D005260:Female; D008297:Male; D015397:Program Evaluation; D051381:Rats; D018675:Toxicity Tests / Q000191:economics / Q000379:methods* / Q000592:standards; D014481:United States; D014484:United States Environmental Protection Agency; D015262:Xenobiotics / Q000633:toxicity*
chemical_list: D052244:Endocrine Disruptors; D015262:Xenobiotics