Prenatal Origins of Endocrine DisruptionCritical Windows of DevelopmentCritical Windows of Development at a GlanceWhat human diseases and disorders have been linked to prenatal chemical exposure? Diabetes, obesity, infertility, asthma, osteoporosis, autoimmune disorders, cryptorchidism (undescended testicles), hypospadias, cancer of the prostate, testicles and breast, juvenile cancer, autism, attention deficit hyperactivity disorder, Parkinson’s disease and Alzheimer’s disease What are endocrine disruptors?Endocrine disrupting chemicals (EDCs) are chemicals that affect the exquisitely balanced system of glands and hormones that regulates such vital functions as body growth, response to stress, sexual development and behavior, production and utilization of insulin, rate of metabolism, intelligence and behavior, and the ability to reproduce. It also has been proven that a large number of EDCs can penetrate the womb and cause adverse developmental and reproductive disorders at extremely low concentrations. Examples of EDCs include Bisphenol A (BPA), dioxin, PCBs, phthalates, PBDEs, DDT and other pesticides. Why are developing embryos more at risk?Unfortunately, the placenta does not fully protect the baby from chemicals in the mother’s body and exposure during prenatal development can be more devastating than adult exposure for several reasons. The barrier that protects the brain from chemicals in the blood is much more permeable than it is in adulthood and the liver may be too immature to detoxify the body of harmful chemicals. Most important, the embryo and fetus are undergoing a period of extremely rapid cell differentiation and tissue construction while the brain is being programmed. Improperly differentiated cells pass on bad programming to their numerous descendent cells, potentially resulting in poor function or malfunction throughout life (or only expressed later in life). In many instances, damage done prenatally is irreversible. What is the Critical Windows of Development?The Endocrine Disruption Exchange (TEDX) created the Critical Windows of Development in order to take the vast and complex research related to low-level exposure to EDCs and reduce it to a simple computerized on-line accessible product that anyone can learn to use as rapidly as a computer game. First, we created a timeline of normal human development from fertilization to birth. Then we took the extensive, scientific literature on low-dose exposure to EDCs in laboratory rats and mice and overlaid the findings on the timeline of normal human development. With just a click of the mouse you can see what systems, glands and organs are affected by exposure at specific time points during gestation and you can click to see what is occurring at that same time point in human development. Details of each study design are available at a glance, as is the study citation, which is linked to a copy of the original published study. The first three chemicals chosen for the timeline are BPA, phthalates, and dioxin. Future chemicals include PCBs, PBDEs, DDT and more. It is important to note that we did not interpret the research, we simply recorded it. The Critical Windows of Development was peer reviewed by over 50 scientists prior to being made public. Who will use the Critical Windows of Development?Scientists will use it to guide research; medical professionals will use it to promote preventive behaviors; the media will use it to research stories; and policy makers will use it to promote protective regulations. Examples of research findings presented in the Critical Windows of Development include:
To view the Critical Windows of Development go to www.endocrinedisruption.org. |
