When her kids were young, Tracey Woodruff, PhD, MPH – then a senior scientist at the Environmental Protection Agency (EPA) – knew more than most about environmental toxics. But she never dreamed that the baby bottles she used to feed them contained toxic chemicals that could leach into warm milk.
At the time, it wasn’t widely known that chemicals in plastic sippy cups and baby bottles, like bisphenol A (BPA), can potentially disrupt child development by interfering with the hormone system. That, in turn, could impact their reproductive systems or increase the risk of later-life disease.
“I did many of the things we now tell people not to do,” says Woodruff, who has directed UCSF’s Program on Reproductive Health and the Environment (PRHE) since 2007.
Woodruff’s children have grown into healthy teenagers, but many children are not as lucky. Unregulated chemical use is increasing, and prevalent in products we use every day.
Woodruff is concerned by the concurrent rise in health conditions, and believes environmental toxics likely play a role in those conditions. We need to know more so we can reduce our exposure and protect ourselves.
Researchers at UCSF and elsewhere have spent a decade showing that BPA makes it to the blood stream and can harm fetal and infant endocrine systems. The FDA outlawed BPA in baby products in 2012, and some manufacturers developed BPA-free products. Now scientists believe the chemicals that replaced BPA may be just as harmful.
Furthermore, BPA is only one in a long list of chemicals we encounter every day, and scientists have barely scratched the surface of understanding them. Of the thousands of chemicals registered with the EPA for use by industry, the agency has regulated only a few.
“In the last 50 years, we’ve seen a dramatic increase in chemical production in the U.S.,” Woodruff explains. Concurrently, there’s been an increase in conditions like attention deficit hyperactivity disorder (ADHD), autism, and obesity. “It’s not just genetic drift.”
In the last 50 years, we have seen a dramatic increase in chemical production in the U.S.”
And we’re all at risk from increasing synthetic chemical exposure – these chemicals are in our tap water, body lotion, shampoo, and even household dust.
Preventing exposure in babies
PRHE experts do more than measure such trends. They also collaborate with clinical scientists and obstetricians at Zuckerberg San Francisco Hospital so their findings directly benefit pregnant patients.
Though toxics affect us all, pregnant women and children face the greatest risk. Exposure during critical developmental stages can have outsize effects, making them especially detrimental to fetuses, infants, children, and adolescents.
The U.S. Centers for Disease Control and Prevention (CDC) began measuring human exposure to chemicals in 1976. These studies found a range of toxics in subjects’ blood and urine – substances like DDT, BPA, pesticides, and phthalates.
Phthalates, for example, a class of chemicals known to be endocrine disruptors, are widely used as plastic softeners and personal-care product lubricants. Women of reproductive age evidence higher levels of phthalates than the general population, partially because they use more of products like deodorant, shampoo, and conditioner.
Woodruff recently led a study in which UCSF researchers collected blood samples from pregnant women at ZSFG. After they delivered their babies, researchers collected umbilical cord blood samples and discovered that almost 80 percent of the chemicals in the maternal blood were also in the cord blood.
The good news is that following bans on certain phthalates, for example, UCSF researchers measured declines in urinary concentrations of the prohibited types in a U.S. population sample.
Policies for the people
“It’s important to realize there are things you can do to lower your exposure to toxic chemicals, but some things you can’t do.”
For example, Woodruff explains, no amount of personal awareness could protect someone from lead before leaded gasoline became illegal. It was in the air everyone breathed.
“When the government acts to reduce exposures to toxic chemicals we see positive change,” she says.