The U.S. Environmental Protection Agency (USEPA) is validating an assay for use in determining the adverse consequences of exposure to endocrine-active substances on the development and reproduction of birds. The assay involves exposing adult Japanese quail (Coturnix japonica) to low levels of chemicals through reproductive development, mating and egg-laying, then exposing the hatchlings from embryonic development through reproduction. Histopathology is a core endpoint in this test. However, little technical guidance exists describing the collection, fixation, and processing of tissues, or the potential diagnostic criteria and approaches to grading the severity of lesions. Therefore, in an effort to optimize repeatability and reduce bias in the assay, the USEPA is seeking expert guidance for developing protocols for processing tissues, the general histological assessment of tissues, approaches to reading histological studies, determining appropriate diagnostic criteria and severity grading schemes for the criteria, potential interpretive difficulties, and data reporting and analysis.

EPA is identifying qualified pathologists for potential future consultation to develop this guidance. The pathologists ideally shall possess a majority of the following experience/proficiencies/qualifications:

• General practices of toxicologic pathology
• Reading toxicologic pathology studies performed on birds, preferably Japanese quail
• Familiar with normal avian histology and physiology
• Familiar with general responses of avian tissues to toxicologic insult
• Preferably board certified (e.g., American College of Veterinary Pathologists, the European College of Veterinary Pathologists, or other certifying organizations), however if not possible, he/she must have obtained sufficient experience with, and knowledge of avian histology and toxicologic pathology.

Battelle, a private contractor, is supporting the USEPA to identify candidate avian pathologists and submit their names and qualifications to the USEPA. At some time in the future, the USEPA is expected to select those pathologists that will participate in a workshop for developing the guidance document.

Please submit names and qualifications of selected pathologists to Dr. Vincent Brown and Dr. David Houchens by e-mail as follows:

Vincent Brown, Ph.D.	David Houchens, Ph.D.
Battelle	Battelle
505 King Avenue	505 King Avenue
Columbus, Ohio 43201	Columbus, Ohio 43201
USA	USA
brownv@battelle.org	houchensd@battelle.org
Tel. 614-424-5928	Tel. 614-424-3564