Predicting the Future of Children's Health
EPA's Virtual Embryo project is helping scientists understand how chemical exposures might affect a developing embryo.
According to the Centers for Disease Control and Prevention, approximately one in every 33 babies born in the United States is born with a birth defect . Birth defects range from mild to severe, and may result in long-term disabilities or increase the risk of illness. Although the causes of most birth defects are unknown, some are associated with environmental exposures and certain nutritional deficits. In these cases, some birth defects could be prevented.
EPA researchers are hard at work studying how environmental exposures to chemicals could lead to birth defects. They are tapping powerful, high-tech computer systems and models to better determine how prenatal exposure to chemicals might impact embryo and fetal development. EPA’s Virtual Embryo (v-Embryo™) project creates computer models of developing body systems and combines them with data from a number of EPA studies, toxicity databases, and EPA’s ToxCast (see ToxCast story in this issue) to “virtually” examine the effects of a variety of prenatal exposures.
Virtual Embryo models simulate how chemicals, including those that disrupt the endocrine (hormone producing) system, interact with important biological processes that could disrupt fetal development. The chemicals used in simulations have been identified by ToxCast as having the potential to affect development.
The predictions from the computer simulations need to be further tested against real world, non-virtual observations. However, the models provide scientists with a powerful tool for screening and prioritizing the chemicals that need to be more closely examined, greatly reducing the cost and number of targeted studies needed.
“We’ve built small prototype systems, now what we want to do is move into complex systems models that will be more relevant to environmental predictions,” said Thomas B. Knudsen, Ph.D., an EPA systems biologist who is leading the project.
Virtual Embryo models simulate blood vessel development and limb development, and are being expanded to include early development of the male reproductive system, which is known to be particularly sensitive to endocrine disrupting chemicals.
Knudsen says that having more models is important because different chemicals can affect biological systems in various ways. Luckily, the time it takes to develop new models decreases as researchers’ model-developing knowledge grows.
“The important challenge for us is to try to integrate some of this work with other issues of broad importance to children’s health,” said Knudsen. “We’re focused primarily on embryonic development, but a person doesn’t stop developing at birth. We have to take what we are learning from the embryo and extend that information into life stages beyond birth.”