30 Breakthroughs: Environmental & Human Health

November 10, 2021

Avner Vengosh

Forensic Fingerprinting

The number of manmade or natural contaminants that can pollute our water and soil is huge and they rarely occur in isolation. Teasing out which contaminants are in play at a site, and where they originate, is vital for protecting environmental and human health.

That’s where Avner Vengosh comes in.

Vengosh, Distinguished Professor of Environmental Quality, has developed a suite of tests—he calls them “forensic tracers”—that can identify a contaminant by its unique isotopic or geochemical fingerprint and conclusively track it back to its source, which will have a matching fingerprint.

Vengosh has used the tracers to detect, measure and trace the source of coal ash residuals, radioactive brine from fracking wastewater, naturally occurring uranium, methane, hexavalent chromium (a known carcinogen), and other contaminants at sites worldwide—winning ‘best of year’ honors for his team’s studies three times from the American Geophysical Union and its journals.

Snuffing Out Risks from Flame Retardants

Flame retardant coatings are supposed to keep us safe by slowing the time it takes a spark that lands on clothing, cushions, mattresses, carpets, baby products and other common household items from bursting into flame. Instead, there’s now overwhelming evidence linking flame-retardant chemicals to neurodevelopmental delays, obesity, endocrine and thyroid disruption, cancer and other diseases. Children are particularly susceptible.

Research by Heather Stapleton, Ronie-Richelle Garcia-Johnson Distinguished Professor of Environmental Chemistry, is helping reduce the dangers.

Through years of scientific sleuthing, Stapleton and her team have identified the proprietary mixes of chemicals used to formulate many flame retardants used in upholstered furniture, children’s products and other goods (Manufacturers don’t have to disclose this information). Working with colleagues in related health fields, they’ve conducted extensive testing to assess the health risks posed by these chemicals.

A 2011 study, which showed that 80% of the children’s products tested by Stapleton contained flame retardants in their foam, was named the top science paper of the year by Environmental Science & Technology and helped persuade the State of California to change its foam flammability standard so that products such as strollers, infant carriers and nursing pillows no longer need flame retardants.

The Air We Breathe

Jim Zhang studies the links between air pollution and human health. But Zhang, professor of global and environmental health, doesn’t merely document these links. His research focuses on finding better ways to detect or prevent the diseases.

One recent study, for example, focused on malondialdehyde (MDA), an organic compound that’s a biomarker of oxidative stress and a widely used indicator of asthma, cancer and other health problems associated with air pollution. There are two types of MDA that are often used interchangeably. Findings from Zhang’s study give doctors new clarity on which type is more effective for detecting disease in urine, exhaled breath condensate, or serum samples—a vital consideration.

In another recent study, Zhang showed that using high-performance HEPA air filters in asthmatic children’s bedrooms when outdoor air quality is bad, helped the children breathe easier and, with consistent use, could prevent—not just alleviate—asthmatic flare-ups.

“Pharmaceutical companies have spent large amounts to develop drugs that can work on lower airways, but they are very expensive. Our results suggest that using an air purifier could help asthmatic children breathe easier without those costly drugs,” he says.

Of Fish and Men

Documenting the acute effects of exposure to environmental toxins can be difficult. Tracking the lifelong and evolutionary consequences of exposure? That’s a whole order of magnitude tougher.

And it’s exactly what Rich Di Giulio is doing.

Di Giulio, who directs the Duke Superfund Research Center, has devoted much of his career to understanding the effects of polycyclic aromatic hydrocarbons (PAHs) on embryonic development, later-life health, and behavioral adaptations in killifish, an otherwise unremarkable species of “bait” fish that, over generations, has developed a remarkable ability to adapt—at a high metabolic cost—to the PAH-polluted waters of southeast Virginia’s Elizabeth River.

Di Giulio’s studies, which often involve the use of a DNA-based probe he co-developed, show when certain genes are blocked, PAHs exert a greater toxic effect on the fish and may increase their risks of liver cancer and heart deformities, and may lead to reduced resistance to other environmental stresses. When different genes are blocked, the effect is lessened.

Exploring if this genetic dimmer switch and other biological mechanisms he’s identified in killifish might hold clues to reducing the effects of exposure to harmful chemicals in other species, including humans, is a growing focus of Di Giulio’s work.