Newswise — New findings of a multi-university research team show the pesticide DDT persists in remote lakes at concerning levels half a century after it was banned, affecting key aquatic species and potentially entire lake food webs.
“What was considered yesterday’s environmental crisis in the 1950s through 1970s remains today’s problem,” says lead author Dr. Josh Kurek, Assistant Professor in Geography and Environment at Mount Allison University. “Decades of intense insecticide applications to our conifer forests have left a lasting mark on these lakes—and likely many others in eastern North America.”
Between 1950 and 1970 prior to legal restrictions, dichlorodiphenyltrichloroethane (DDT) insecticides were widely applied to eastern North American forests to manage naturally occurring insect outbreaks, such as spruce budworm. Although often applied to forests by airplane, chemicals like DDT are highly persistent and can eventually wash into lakes from their surrounding landscape. This study looked at dated sediments from the bottom of five remote lakes located within different watersheds in north-central New Brunswick, Canada. Lake sediments provide a well-recognized and powerful archive of environmental conditions, which allows researchers to assess chemical and biological conditions in lakes before, during, and after pesticide use.
The study was recently published in the peer-reviewed journal Environmental Science & Technology of the American Chemical Society, the world’s largest scientific society, highlights the chemical legacy of one of North America’s largest aerial spray programs of insecticides ever coordinated by forest stakeholders.
