In recent years there has been increasing concern about the impact of PFAS on humans and our environment. Now, scientists have found high levels inside turtle populations. Could this be a threat to future populations of these iconic animals?
PFAS chemicals (perfluoroalkyl and polyfluoroalkyl substances) are in a range of products, including non-stick cookware, stain resistant carpet and firefighting foam. Although it is beginning to be phased out, once it is in the environment, PFAS chemicals leach into soil and waterways. It is never broken down naturally, hence the dub “forever chemicals.”
A recent joint study by CSIRO (Australia’s national science agency) and the Queensland Department of the Environment, tourism, and Innovation (DETSI) investigated the impact of these ‘forever chemicals’ on freshwater turtle populations in Queensland. It looked at 350 wild freshwater turtles over a period of three years.
David Beale, a senior CSIRO research scientist, said that the study did “a deep analysis of thousands of biochemical molecules, proteins and lipids to understand the trajectory of their health in these contaminated environments.”
“PFAS concentrations were up to 30 times higher in the blood and organs of turtles from highly contaminated area, compared to the control sites where there were low levels of PFAS in the water,” says Suzanne Vardy, DETSI principal scientist.
Through this work, the team “found a whole range of biomarkers that are indicative of cancer and other health problems,” says Beale.
It also found that “adults had a high potential of forming gout” (which is deadly in reptiles)” and that “PFAS impacted essential metabolic processes in the turtles,” he says.
It wasn’t only adults who were exposed. Vardy said that “[they] found that there was a lack of juveniles at the more contaminated sites.” Eggs that were present had “altered ratios of essential mineral, and hatchlings had a high rate of defects in their shells”.
“Our models predicted that overtime, these impacts could result in a population collapse,” she said.
Beale agreed, stating that it was “concluded that we’ve got significant health problems in these turtles that isn’t immediate, but over a generation would be quite profound.”
He was also very concerned that “[they] still saw evidence of harm [by PFAS]”, even at sites which were not directly contaminated.
“We really need to jump on this issue of ecological toxicity,” says Jean-Luc Cartron, a Biologist at University of New Mexico in Albuquerque, who was not involved in the study, “if the [study] authors are right, and the lack of juveniles that they see out in the environment is caused by PFAS, we don’t want to wait until we’re missing a whole full generation of animals”
The team is continuing to work on freshwater turtles but also investigating the effect on other species, such as crocodiles, cane toads and frogs across Queensland, New South Wales, and Victoria.
“All these animals that we love in the wild are being exposed to these chemicals, and we’re just not seeing the obvious impacts of those exposures,” warns Beale, “My greatest fear is in 10, 15 years’ time, we might see those impacts and it might be too late.”