Plan Author

Emma McCamant, 2014

Project Description

A review of the effects of endocrine disrupters on reproductive health.

Outside Evaluator

Laura Vandenberg, University of Massachusetts Amherst

Sample Courses


Recently, scientists have been putting renewed effort into researching the idea that many foods as well as products that humans rely on to make their daily lives more comfortable and simple contain chemicals that may be detrimental to human health. These chemicals, both natural and synthetic are found in almost everything from food products and their storage containers, to cosmetics and toiletries. Scientists are concerned that many of the chemicals that make up these goods and foods fall under a class of chemical known as endocrine disruptors.

Simply put, endocrine disruptors are chemicals that interfere with the endocrine system and, in doing so, may adversely affect human development and reproduction. According to both the EPA and the European Union, endocrine disruptors are more specifically defined as chemicals from an outside source that enter the body and interfere with the production, release, transport, and attachment of the body’s endogenous hormones that maintain homeostasis. Because these chemicals are capable of preventing normal processes from occurring, serious harm can be done to the body over time. Perhaps the most concerning part about this class of chemicals is that many of them are commonly used in products and foods that humans rely on regularly, so people come into contact with them often. Moreover, since research on endocrine disrupting chemicals is relatively new, many people are not necessarily aware of the risks that they may be coming into contact with on a regular basis.

As a result of being a relatively new research topic, how harmful the chemicals may be to humans remains somewhat of a mystery. Much of what contributes to this confusion is the conflicting evidence that has been uncovered through research. Some studies find that some of the endocrine disrupting chemicals that humans are exposed to are in a concentration so low that it is not possible for them to cause harm, while other studies have shown that endocrine disruptors may actually be potent enough to adversely affect human health regardless of low concentration. For every study that claims endocrine disruptors are of no concern, there is a study that claims these chemicals may be incredibly detrimental to humans. Moreover, another difficulty that comes with researching these chemicals is that very small amounts of these chemicals have potentially large impacts on the body and humans are exposed to so many chemicals throughout their lifetimes that it becomes difficult to pinpoint the specific problem chemical. As a result, it may take many studies to be able to figure out what chemical causes what reaction in the body. Because of such conflicting evidence as well as other difficulties, particularly within reference to humans, it is going to take much more time and research to come up with a definitive answer about endocrine disruptors. In this paper, I will review some of the evidence for the detrimental effects of endocrine disruptors on human reproduction.


“Once an endocrine disruptor enters the system, there are several ways in which it can act including mimicking or blocking the effects of natural hormones, disrupting the synthesis of natural hormones, or disrupting the synthesis of the hormone receptor. The first mechanism, mimicking and/or blocking hormone effects, occurs when a chemical that resembles the natural hormone enters the body and binds to the hormone receptor. If the chemical is structurally similar enough to the natural hormone, it may bind to the receptor and trigger the same sequence that the hormone would. However, if the structure of the chemical differs too greatly from the natural hormone, it may simply bind to receptor and, by doing so, block hormones from being able to initiate natural sequences.”

“The effectiveness of the one-child policy is still under examination. China’s total fertility rate did, in fact, decrease from 2.9 in 1979 to 1.7 in 2004. However, the policy may only be partially responsible for the decrease. Moreover, as of 2006, China still had one million more births than deaths every five weeks. So, although the government has tried to control fertility and birth, the population size is still high because the fertility rate exceeds the population replacement rate.”


The inspiration for my Plan was a tutorial on reproductive biology I had with Jaime Tanner, when we just covered broadly the topic of human reproduction. What I remember most from the process was exhaustion!