“ Our bodies are the piano,
but our hands are the environment”
UPdate Summer 2007
Our ability to reproduce - and the health of our children and even our grandchildren - hinges on an exquisitely timed series of chemical reactions controlled by infinitesimally tiny amounts of hormones.
We scramble those reactions at our peril. Hundreds of researchers gathered at the first Summit on Environmental Reproductive Health in San Francisco in January 2007 warned that synthetic chemicals in common use may be doing exactly that.
The chemicals which most affect reproductive health are endocrine disrupters. These chemicals are found everywhere in our environment: our food, lotions, shampoos, baby bottles, toys, appliances, even the casings encapsulating our medicines. They mimic hormones at levels scientists have only recently been able to measure. Some are active at concentrations of a part-per-trillion or less - like a speck of dirt sullying 55 tons of clean laundry.
Most worrisome to scientists: In many cases the effect of such pollution on our bodies remains as mysterious as the processes they potentially disrupt.
"In the absence of concrete data for many of these chemicals, the precautionary principle should be exercised," said Dr. Linda Guidice, chairwoman of obstetrics, gynecology and reproductive sciences at UCSF and the organizer of the conference that brought together 500 scientists, clinicians and community activists concerned about reproductive health.
The list of potential effects, scientists concluded, stretches across every aspect of reproductive and sexual development - preconception, conception, pregnancy, puberty, menstruation, and menopause.
Every key developmental stage is driven by a tightly choreographed fluctuation in hormones. Scientists are warning that a flood of endocrine disrupters is disrupting that dance.
The science of endocrine disrupters is still controversial. The effects in humans are uncertain. Government panels assessing the weight of the evidence for many of these compounds repeatedly have found no need for concern. But scientists say disturbing gaps remain in our knowledge.
- Several studies have shown pesticides suppress fetal testosterone in laboratory animals. But scientists can't fully explain the consequence. They don't even know the role testosterone plays in a baby boy's brain development.
- The womb was once thought of as a gatekeeper, shielding the developing baby from harm. No more. A number of contaminants readily traverse the placenta, and others - synthetic fragrances, for one - are thought to hold the door open, so to speak.
- Female mice exposed in utero to bisphenol-A, an estrogenic additive used in many products, including to line food cans and make plastic shatterproof, saw a 40 percent increase in chromosomally abnormal eggs, according to one research team.
DES, diethylstilbestrol, the “wonder drug” given with the best of intentions from the 1940s to the 1970s to protect pregnant women from miscarriage sounded an early warning of the potential intergenerational impacts of endocrine disruptors. DES did not harm pregnant mothers, but it ravaged the reproductive tracts of their children.
DES did its damage, scientists now know, because it turned hormones on at a time during fetal development when they would normally be silent. That, researchers say, is exactly what bisphenol-A and a soup of other endocrine-disrupting compounds do.
Sandra Steingraber, a noted ecologist, author and cancer survivor, is vehement about the risks environmental chemicals have for children, and our children’s children.
"We need to start thinking of our reproductive lives as a live musical performance. Our bodies are the piano, but the hands are the environment," she said. "We are nothing less than the receivers of environmental messages. As that message changes, we are changing ourselves."
The Summit on Environmental Reproductive Health was co-sponsored by the Collaborative on Health and the Environment (CHE), and the University of California, San Francisco. (UCSF).
Thanks to Douglas Fisher, Oakland Tribune
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