Endocrine Disruption

The ability of environmental contaminants to affect reproductive and developmental processes in fish and wildlife species has long been known. An increasingly persuasive body of evidence indicates that many of these chemicals may be causing such effects through interference and disruption of normal endocrine function. Field observations have correlated abnormal sex organ morphology, unusual sex hormone levels and ratios, and altered physiological and biochemical processes with exposure to environmental contaminants. These developmental end points are under the control of the endocrine system, lending support to the hypothesis that environmental contaminants may disrupt endocrine function.

The USGS Contaminant Biology Program investigates the exposure and effects of contaminants on fish and wildlife and focuses on Endocrine Disruption as a part of Toxicology component of the research. It closely collaborates with two other USGS programs - Toxic Substances Hydrology and the National Water Quality Assessment, which conduct research and monitoring (respectively) to determine the presence and chemical fate of contaminants in aquatic environments.

• Assessment of Health Reproduction in Fishes from the Potomac River and Selected Other Drainages (LSC)
  
  
• Development of Methods to Determine the Reproductive Status of Pallid Sturgeon in the Missouri River - the final Science Support report to the U.S. Fish and Wildlife Service. Download the report (6.5 MB, PDF -- get Adobe Reader) (CERC)
  
  
• Effects of Estrogen and Related Contaminants on the Expression of Genes Involved in the Innate Immune System of Fish in Rivers of the Chesapeake Bay Drainage (LSC)
  
  
• Environmental Assessment of Endocrine-disrupting Chemicals (CERC)
  
  
• Environmental Endocrine Disrupters: Effects and Possible Mechanism(s) in Young Male River Otters (FRESC)
  
  
• Fish Health and Reproductive Studies at Lake Erie Areas of Concern (LSC) ( (brown bullhead and largemouth bass)
  
  
• Hormonal Control and the Effects of Endocrine-active Contaminants on Avian Secondary Sex Characteristics (PWRC)
  
  
• In Vivo Health Effects of Bisphenol A. Download the Publication Brief from Columbia Environmental  (329 KB, PDF -- get Adobe Reader) (CERC)
  
  
• Investigations of the Effects of Synthetic Chemicals on the Endocrine System of Common Carp in Lake Mead, Nevada and Arizona. Download the Fact Sheet (428 KB, PDF - get Adobe Reader)
  
  
• Potential Endocrine Disruptors in the Potomac River Watershed Using Passive Samplers (PWRC) (Also related to Chemistry: Passive Samplers )
  
  
• Reproductive Condition and Intersex Occurrence of Bighead Carp and Silver Carp in the Missouri River. Download the Publication Brief from Columbia Environmental Research Center. (237 KB, PDF--get Adobe Reader) (CERC)
  
  
• Reproductive Performance and Associated Developmental and Endocrinological Effects of Polychlorinated Biphenyls (Aroclor 1242) on Captive American Kestrels (Falco sparverius) (PWRC)
  
  
• USGS Endocrine Disruptor Projects in Biology (CERC)

	What does the endocrine system do? The cells, tissues, organs, and glands of the endocrine system secrete hormones that regulate development, reproduction, metabolism, behavior and homeostasis. Hormone Physiological function insulin metabolism estrogen reproduction thyroid hormone growth adrenaline stress response What do endocrine disrupter do? Endocrine Disrupters interfere with the synthesis, secretion, transport, activity, or elimination of natural hormones. This interference can block or mimic hormone action, causing a wide range of effects. Endocrine-active chemical Physiological effect DDT disrupts function of sex metabolites or hormones, causes eggshell thinning, and other problems PBDEs (Polybriminated diphenyl ether flame retardants) disrupts thyroid function Bisphenol A estrogenic How widespread is endocrine disruption? This question continues to plague scientists and environmental managers. Though there are many examples of endocrine disruption in the environment, determining its prevalence is a much more difficult task. USGS continues to work on different approaches to solving this problem using models, land use information and nationwide reconnaissance efforts, but considerably more effort will be needed before a clear understanding emerges.