Award-winning research conducted in part by a scientist at the Great Lakes Institute for Environmental Research could lead to better advisories about the safe consumption of fish as well as improved methods for screening chemicals before they’re released into the environment.
“This provides scientific rationale for how to establish risk assessments and safety guidelines,” said Ken Drouillard, the second lead author on a paper that explains the differences between laboratory and field data used to measure a process known as bioaccumulation.
Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism, and it occurs when organisms absob toxins at a rate greater than they are lost.
Dr. Drouillard, whose expertise is in contaminant bioaccumulation modelling, was one of a dozen researchers from Canada, the U.S., Denmark, Norway and the Netherlands, who were called together to a workshop hosted by the International Life Sciences Institute in Washington D.C., to better understand the variation between bioaccumulation levels from studies conducted in the field and those anaylzed in laboratory settings.
“We were basically trying to explain why lab studies don’t match what we’ve been seeing in the field,” he said. “We can see variations of contaminant levels in species from the same ecosystems as much as 100-fold.”
Using models previously established at UWindsor, and examining existing literature on the subject, the group conducted modeling simulations of contaminant levels in four species: mayflies, yellow perch, little owls and a variety worms knows as polychaetes. The group found that in the case of worms and mayflies, sediment exposure and sediment composition were more likely to drive variability in bioaccumulation, whereas diet composition and food abundance were more important factors for explaining differences in species at higher trophic levels like fish and birds.
Having this data should help regulatory agencies worldwide when they’re assessing substances for potential hazards and risks according to their persistence, bioaccumulation, and toxicity (PBT), said Drouillard, who coded all of the models for the study. The information would also be useful for regulators who establish guidelines about safe levels of fish that humans can consume, he added.
The paper, which was published in the academic journal Integrated Environmental Assessment and Management, recently received a 2012 best paper honourable mention from the journal’s editors.