Endocrine Disruptors
Article information
Abstract
Abstract
For the previous century, the humans have created an unintended and unwanted problem of endocrine disruptors as a potential threat to our public health. By the name of industrialization, endocrine disruptors are smuggling in the everyday life of people today. Although there are much debate on the reality of their emerging health threat, it is no doubt that there are certain classes of compounds that have the potential to affect hormonal status adversely, leading to abnormal development, reproductive dysfunction, and some cancers. The classes of endocrine disruptors are extensively diverse and even more increasing, such as, polychlorinated biphenyls (PCBs), dioxins, dieldrin, bisphenol A and toxaphene. Although these endocrine disruptors have been prohibited or tightly regulated, many of them are still unrecognized and still used without knowing their potential threat to the biological world. Once they are released into the environment, they usually persist without degradation and even undergo bioaccumulation and bioconcentration in food chain. Comparing with the great concern over the public health, we do not have enough information for these issues. It is now clear that we need further extensive studies for the risk assessment and the protection of human and ecological health from the potential hazards of endocrine disruptors. This article introduces a breif overview of the current status of our knowledge and research on endocrine disruptors.
![Figure 1.](/upload//thumbnails/jkma-50-359f1.jpg)
General mechanism of receptor?mediated actions of endocrine disruptors. 1. Normal: body's hormone binds to its receptor and elicits normal hormonal action 2. Blocked: endocrine disruptor binds to hormone receptor, blocking hormone? receptor binding and its action 3. Insufficient: endocrine disruptor binds to hormone receptor, mimicking normal hormonal action insufficiently 4. Excessive: endocrine disruptor binds to hormone receptor, mimicking normal hormonal action excessively
![Figure 3.](/upload//thumbnails/jkma-50-359f3.jpg)
Background TEQ exposures for North America by pathway. TEQ (Toxic Equivalence Factor). TEQs, are used to report the toxicity?weighted masses of mixtures of dioxins. Dioxin compounds are given equal or lower Toxicity Equivalence Factors (TEFs), with each number roughly proportional to its toxicity relative to that of 2,3,7,8?TCDD whose TEF=1. Developed by the World Health Organization (17).
![Figure 4.](/upload//thumbnails/jkma-50-359f4.jpg)
Wildlife species affected by endocrine disruptors. 1. "Freaky Frogs", Frogs with various kinds of deformities have been found in many U.S. states and Canadian provinces from 1995. The top candidates are mammade pesticides, but not clear yet. The research is still ongoing. 2. "Teeny Weenies", Male alligator in Florida's lake Apopka has 25% smaller penis size than in normal males, due to the severe chemical spill of DDT and dicofol into the lake. 3. "Drastic Deformities", Cormorants in the Great Lakes have had nineteen types of deformities, due to the dioxin?like PCB contamination of the lake. 4. "Infertile Felines", Florida's panthers have reproductive problems of low sperm counts, abnormal sperm, undescended testicles, thereby becoming endangered species, due to dioxin, DDT, PCBs etc. 5. "Humans at Risk?", Are environmental pollutants the real culprit in declines in male fertility and increases in breast cancer? (18)