Detecting harmful chemicals in coastal waters

CSI engineer Loretta Fernandez creates novel tools to detect chemicals in coastal waters and develop ways to remediate them. “We try to figure out how these chemicals are getting into the environment, how they move, and where they end up,” she says.

“Persistent organic pollutants,” including many chemicals found on roads or in lawn-care products, make their way through rain runoff into marine environments, where they break down very slowly. Traces of these chemicals invade and harm the tissues of marine organisms, such as fish and invertebrates, and potentially end up in humans through the water we drink and the fish we eat.  

A traditional testing tool—a water sample—only offers a snapshot of one moment in time, and it must go through a series of pumps and filters to yield meaningful data. Instead, Fernandez creates polymer-based devices that can “hang out” in a marine habitat—in the water column or the sediments below—and track chemical levels for months.    

In one project, Fernandez collaborated with the Environmental Protection Agency and used her device to track pollution levels near the Palos Verdes Shelf off the coast of Los Angeles County. A company that produced the chemical insecticide DDT had for decades discharged toxic waste into that marine environment. Attempts to remediate the area—where chemicals were still present at high levels—focused on “capping” the most polluted areas (sediments near the outfall pipe) with new sand. But Fernandez’s detection device showed that similar levels of DDT were present above and below the cap—offering proof that the remediation method was ineffective and should be changed.   

Fernandez has tracked other water-polluting chemicals as well. For example, she’s currently measuring how estrogens—naturally occurring chemicals found in human waste that are not eliminated through the wastewater treatment process—are changing fish species in New England. She’s also developing a new tool to detect so-called “energetic compounds,” or the toxic explosives that were left behind in waterways during the world wars.   

Contact faculty researcher Loretta Fernandez.

Author: CSI Staff