Avian
Endocrine Disruptor Studies
Concern about chemically mediated modulation of normal endocrine (hormonal) function in wildlife and humans has become a focal point of concern in the scientific community and the public as a whole. In 1996, the Food Quality Protection Act (section 408(p)) took action on this concern and directed the EPA to develop a screening program that would determine which chemicals may have hormone-altering effects. Based on this mandate, EPA’s Endocrine Disruptor Screening Program (EDSP) was established. The program has involved research and development aimed at establishment of testing guidelines for aquatic and terrestrial organisms. Some of the guideline development work is still underway.
In 2009 EPA began issuing data call-ins (DCIs) for the first 67 chemicals to be scheduled for testing under the EDSP program. Over time, the program intends to cover all pesticide chemicals. The current list of chemicals designated for testing is available on EPA’s website. The screening program is divided into a two-tiered design. Tier 1 consists of 11 screening assays for the potential of a specified chemical to interact with estrogen, androgen, or thyroid hormone systems. Tier 1 testing guidelines can be found here. If a chemical tests positive for potential hormonal interactions under the Tier 1 phase, it is then scheduled for Tier 2 testing. Vertebrate animal testing begins under Tier 2, as described on the OPPTS website. Avian concerns are included in Tier 2, in the form of a proposed two-generation reproduction study.
Smithers Viscient’s leading toxicology experts are participating in development of the testing guidelines for both Tier 1 and Tier 2 phases. Larry Brewer is leading the avian toxicology department as we partner with other leading CROs to test various measurement endpoints under consideration for the current two-generation reproduction draft guideline. Our staff can assist clients with other EDSP questions regarding Tier 1 screening assays and fish testing guidelines proposed for Tier 2 testing. Smithers Viscient provides services that meet all regulatory endocrine testing requirements.
In addition to laboratory testing of potential endocrine disruptor chemicals, Smithers Viscient has also developed field deployable techniques to monitor exposure of avian species to environmental estrogens. Both laboratory and field-deployable techniques have been developed to measure hormonal status in various measurable parameters from excreted hormones to mate selection and nesting behavior. Though the application of our own techniques are very broad and can be customized to fit a multitude of data needs, we welcome the opportunity to explore new and unique techniques as needed.
