By Hannah Sparks (April 27, 2021)
Marine researchers in the Pacific say they’ve unearthed an underwater dump of as many as 25,000 barrels — an estimated 350 and 700 tons — of toxic DDT in what they believe to be a long-forgotten waste site dating back to World War II.
Scientists at University of California San Diego’s Scripps Institution of Oceanography used underwater “Roombas” — drones with sonar technology — to trawl more than 36,000 acres of seabed between Catalina Island and the waters off the coast of Los Angeles, a region previously known to contain high levels of DDT in the ecosystem.
Images snapped during their search show 27,345 “barrel-like” objects containing the insecticide, the Associated Press now reports, just 3,000 feet below the water’s surface.
Shipping logs dating back through the century show that Southern California’s industry had used the area of seafloor as a dumping site until 1972, when the so-called Ocean Dumping Act went into effect.
Eric Terrill, director of the Marine Physical Laboratory at Scripps Institution of Oceanography, called the discovery “staggering.”
“It really was a surprise to everybody who’s worked with the data and who sailed at sea,” said Terrill, the excursion’s chief scientist, during a press conference on Monday.
More testing is needed to confirm the presence of DDT and whether surrounding water, sediment and sea life has been contaminated.
A 2015 study by Scripps oceanographer and professor of geosciences Lihini Aluwihare first identified high amounts of DDT and other synthetic chemicals stored in the fat of deceased bottlenose dolphins.
“These results also raise questions about the continued exposure and potential impacts on marine mammal health, especially in light of how DDT has been shown to have multi-generational impacts in humans,” said Aluwhihare, who was not involved in the recent barrel search.
First developed in the 1940s, DDT was originally used to ward off malaria, typhus and other insect-borne diseases in humans, as well as providing insect control for US crops. Bolstered by Rachel Carson’s “Silent Spring,” a book that prompted widespread concern over the rampant use of manmade pesticides, the newly established Environmental Protection Agency ordered a stop to DDT in 1972 following public outcry. Since then, studies have shown its potential for damage to the environment and human health, including a risk of developing cancerous tumors at high levels of exposure.