Toxin Avenger

Dr. Frederica Perera has always been enchanted by science. As a kid, she preferred to curl up with a biography of Madame Curie or Darwin’s On the Origin of Species rather than books about Nancy Drew or the Hardy Boys. “I also remember being fascinated by the success of Jonas Salk’s polio vaccine in 1955,” she says. It’s fitting that this inquisitive girl grew up to conduct her own groundbreaking research in the arena of childhood health—most notably by proving that prenatal exposure to common environmental pollution can lead to serious health and behavioral problems later in life.

Perera, an NRDC trustee and the founding director of the Columbia Center for Children’s Environmental Health, originally intended to make her mark in the health field as a doctor. But after earning a bachelor's at Harvard and preparing to go to medical school, she saw an art exhibition that changed everything.

“In the early 1970s, a photo essay by Eugene Smith about the disaster at Minamata Bay had a huge impact on me,” Perera recalls. For years, the Chisso Corporation had dumped wastewater containing mercury into the Japanese bay, and Smith’s images documented the lasting effects on the human population. The cerebral palsy-like conditions and mental retardation of the children born to women who had eaten the contaminated fish struck Perera, a mother of four young children herself, particularly hard.

“Like all new moms, I was acutely aware of my children’s vulnerabilities and the need to protect them,” Perera says. “I wanted to find a better way to study the relationship between pollutants and health.” Typical studies at the time vaguely monitored area-wide chemical exposure and tried to find relationships between that data and the number of serious diseases and deaths. “I thought there must be a better way to connect the dots between exposure early in life and outcomes later on," she says, " so we could focus on prevention and not just recording death.”

Figuring she would have a better shot of doing that by studying environmental science and public health instead of medicine, Perera headed to Columbia University to begin her postgraduate work. After coauthoring a book on the effects of air pollution on human health in 1979 and growing frustrated by the lack of information available, she approached her doctoral advisor, molecular epidemiologist and physician Dr. Bernard Weinstein, with a plan for a new kind of research.

Perera wanted to create a human study that would piggyback on intriguing experimental lab research she had seen. It was possible to see and measure the “fingerprints” of airborne pollutants (called polycyclic aromatic hydrocarbon, or PAH) in the DNA samples of people exposed to the chemicals, and then examine the relationship between those markers and lung cancer. “If we could open that black box, it could tell us how much of an exposure dose a person had, and we could flag risks well before the disease was entrenched,” Perera says.

During the next year, Perera searched for those telltale molecular markers in tissue and blood samples from people with and without lung cancer. She then moved on to study secondhand smoke—first with adults and then with preschool-age children. As a control, she collected placental and cord blood, and was shocked to find high levels of PAH in what she assumed would be pristine samples. “That was just riveting,” she remembers. “We didn’t realize the extent to which the placenta was allowing the chemicals to move from the mother to the newborn.”

Perera’s internationally recognized Mothers and Newborns Study was built off this revelation—that a person’s susceptibility to toxic chemicals begins before he or she is even born. Starting in 1998, she and her colleagues at the center have tracked the prenatal exposure to common toxic chemicals, and subsequent health and development, of more than 700 mothers and children from low-income neighborhoods in New York City. “We’ve found consistent evidence that various exposures are linked to low birth rate, decreased IQ, depression, asthma, and obesity,” Perera says.

Part of the problem is that a fetus doesn’t have a fully functioning immune system and the ability to detoxify chemicals. “When you look at how fast the brain and respiratory system is developing during this time—most of the 86 billion neurons in the brain are formed before we’re born—you understand how any interference can disrupt this highly choreographed process.”

And of course the other huge part of the problem is that pregnant women, especially those in lower-income communities, are battered by all kinds of dangerous substances every day—from car exhaust to pesticides to power-plant emissions. “Everyone is exposed, but evidence shows that the closer you are to poverty, the greater the impact,” Perera says. Not only are these populations living in areas with the poorest air quality, but their increased stressors weaken their immune systems and magnify the biological effects.

The good news is that the team’s findings have been compelling enough to spark policy changes. For example, children with high prenatal exposures to pesticides tested lower for motor skills and mental development when they were three years old than those with lower exposures. This data helped spur stricter regulations surrounding pesticide use in public housing in 2005. “I received a letter from Mayor Bloomberg that said our research motivated Local Law 37—putting New York at the forefront of safer pest control methods in the United States,“ Perera says.

A similar study conducted by the center in China measured DNA damage in children born before and after a coal-burning plant shut down. “Children born after the plant closed did significantly better on cognitive tests at age two than those we were born when the plant was still in operation,” Perera says. “This is hopeful because it proves that intervention can work.”

Though she received the prestigious Heinz Award for this work in April 2015, Perera is far from finished with her research. ”Winning that award was important in confirming the importance of this work,” Perera says. “There’s still so much we can learn, and we hope funders will realize the benefits of continuing to follow through with this study. Having that continuum is a great advantage in terms of understanding long-term effects. We create the world that our children inherit, and robust science is tremendously important in creating that good and healthy world.”