What are endocrine disruptors?
Endocrine disruptors are exogenous chemicals that interfere with hormone function. They include herbicides, fungicides, insecticides, nematocides, and industrial chemicals such as cadmium, dioxin, mercury, and PCBs.
What are the effects of endocrine disruptors ?
Three common types of hormone inferences are known as mimic effects, blocking effects, and interference effects.1
When an endocrine disrupting chemical mimics a natural hormone, the chemical causes the body to over-respond to the stimulus or respond at atypical times. An endocrine disruptor can block the effects of a hormone from certain receptors by blocking the receptor site or a cell. Some endocrine disruptors directly stimulate or inhibit the endocrine disruptor, causing over or underproduction of hormones.2
Where are sources of endocrine disruptors?
- Endocrine disrupting chemicals can originate from a variety of sources including industrial activities, sewage treatment works, domestic activities, animal feedlots, and agricultural fields (pesticides).
- Some endocrine disrupting chemicals vaporize easily and consequently travel long distances via atmospheric transport. (Colborn et al. 1993)
- Endocrine disruptors are found in rain water, well water, lakes, oceans, soils, freshwater, marine, and terrestrial food products.
Are there any other relevant characteristics of endocrine disruptors?
Many endocrine disrupting chemicals are persistent and lipophilic (Colborn et al, 1993). When an endocrine disrupting chemical is persistent, it takes a long time to degrade in the environment and therefore has an opportunity to travel far distances via water, air, and food. Lipophilic compounds can dissolve in fats and therefore are able to both bioaccumulate within an organism and biomagnify up the food chain. When lower level organisms ingest lipophilic endocrine disrupting chemicals, the substances can accumulate within them. When their predators consume the lower level organisms, they then ingest the endocrine disrupting chemicals that have accumulated in their prey. As the chemicals move up the food chain, more and more of the concentrations of ingested endocrine disruptors increases, becoming potentially more toxic. In addition, greater risk exists for predators at the higher levels of the food chain to consume numerous endocrine disrupting chemicals, among other potentially harmful substances.
1http://embryology.med.unsw.edu.au/Notes/Index/E.htm
2www.ahealthylife.citymax.com/page/page/1922114.htm
Image Sources
Endocrine disruptors: www.igb-berlin.de
Internal Organ diagram: www.comparative-hepatology.com
Mouse: dels.nas.edu
Moluecular structure: www.fda.gov
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