Thirty Years of Monitoring fish PCBs, what can we learn?

Session: Chemical Contaminants (2)

Emily Shaw, Michigan Technological Univ., [email protected]
Noel Urban, Dept. Civil & Environment Eng., Michigan Technological Univ., [email protected]

Abstract

Polychlorinated biphenyls (PCBs) are globally ubiquitous and the most frequent contaminant at US and international areas of concern (AOC). The Michigan Department of Environmental Quality has monitored fish PCB concentrations since 1987; using this long-term data set, this work seeks to answer the questions: what can be learned from the distribution of concentrations and composition of PCBs across the state and can the absence or presence of temporal trends be used to inform changes to monitoring programs?

Significant differences in PCB concentrations were found between AOC and non-AOC sites for three of four fish species (p < 0.05). Total PCB concentrations are calculated as the sum of individual congeners, but different fish species and different locations have different congener profiles and probably different toxicities to humans. Insufficient sampling sites prevents assessment of latitudinal or urban-rural patterns in fish PCB contamination. Temporal trends were difficult to establish in part because of a change in analytical methodology. While half-lives at AOC sites were longer than at non-AOC sites, the small number of sites makes the comparison statistically weak. Periodic reflections on current monitoring program structure is important and provides an opportunity to improve programs to answer on-going and new management questions.

Twitter handle of presenter
@itsmeem35