(Here is a guest post from the NRDC's blog, Simple Steps. It is By Catherine Zandonella, M.P.H. and features an interview with NRDC health scientist (and mom) Dr. Sarah Janssen about how chemicals may impact nursing infants and children later in life, as well as some easy ways moms can reduce chemical exposure, in the womb and in the home.)
This January, a study by the University of California San Francisco confirmed that pregnant women carry multiple chemicals in their bodies that can be passed onto their fetus. Published in Environmental Health Perspectives, the study evaluated data collected by the U.S. Centers for Disease Control and Prevention in 2003-2004. Overall, 43 banned as well as currently used chemicals -- including PCBs, organochlorine pesticides, PFCs, phenols, PBDE flame retardants, phthalates -- were detected in 99-100% of over 250 pregnant women.
Though we have known for many years that humans are contaminated with dozens of chemicals from birth until late in life, this study marks the first time the number of chemicals in pregnant women has been counted. Many of the 163 chemicals studied are known to be transferred to the fetus and have been linked to poor health outcomes, placing them at risk for birth defects or chronic illnesses later in life. Some of the chemicals detected -- such as PCBs -- have been banned for over 30 years.
This study adds to the weight of evidence that unborn babies are exposed to a soup of chemicals during vulnerable periods of development. Furthermore, because the women in the study were tested for exposure to only a fraction of chemicals on the market, it also suggests that pregnant women are likely carrying and passing onto their fetuses many more chemicals than have been reported here. Catherine Zandonella spoke with NRDC senior scientist Sarah Janssen about the implications for women and their children.
Q: What are the possible harmful health effects to a child who was exposed in the womb to these chemicals during pregnancy?
SJ: Over the past several decades, scientists have discovered that exposures occurring early in life, either in the womb or during early stages of childhood development, can cause harm that doesn’t occur when the exposure happens later in life. This is because during fetal, neonatal and early childhood the body is rapidly growing and developing under a carefully orchestrated process that is dependent on stepwise events.
When one of those events is interrupted, the next event is disrupted and so on until permanent and irreversible changes can result. This could result in a very subtle effect -- like an alteration in how the brain develops resulting in changes in attention span, learning ability, or behavioral changes. Or it could result in other impacts like altering where fat cells are deposited in the body or modifying the development of an organ predisposing it to cancer later in life.
Many of these types of studies have been done in laboratory animals, but we do have some evidence gestational exposures are causing human harm. For example, lead, mercury and PCBs have all been shown to harm the developing brain resulting in a loss of IQ points, impaired learning and memory, and behavioral changes.
Q: Can nursing infants be exposed to these chemicals, if so, and what harm might result from breastfeeding?
SJ: Yes, some of these chemicals are found in breast milk. It is frustrating and maddening that a baby’s first food is contaminated with industrial chemicals, but breast milk remains the best form of nutrition for infants.
The benefits of breast feeding outweigh any of the risks -- including exposure to chemicals. We have information about the benefits to mom and baby on our website.
In addition, there have been some studies that have shown breast feeding can counter some of the harmful effects often seen after exposure to PCBs in the womb. Bottom line is that while we work to eliminate the most harmful chemicals from our breast milk -- breast remains best!
Q: Can fetal exposure to chemicals in the womb cause problems with fertility and reproduction later in life?
SJ: Yes, it is likely. Because gametes -- the cells that form sperm and eggs -- are formed in fetal life and reproductive organs are also forming throughout gestation, exposures to chemicals during this time can permanently alter these structures and result in infertility that isn’t manifest until several decades later.
For example, from animal studies we know that exposure to phthalates during fetal development can result in malformed genitals, poor sperm quality and even testicular cancer. Preliminary studies in humans have linked phthalate exposure during fetal development to a feminization of the genitals, though it isn’t yet known whether this results in reproductive harm.
Read the rest of the Q&A here: http://www.simplesteps.org/health/pregnancy/toxic-chemicals-pregnant-women-qa-sarah-janssen
