What evidence did ottawa scientists collect in researching pcb concentrations in alaska?

The correct answer is PCBs were found in greater concentrations in lakes where more salmon spawned. It also worked vice versa as smaller amounts of PCBs were found in lakes where fewer salmon spawned. This led to great polemics on safety and on how it should be reduced.

Themes; subfields is the answer

Answerbecause of improved transportation, communication, and other advantages;