As far as I personally know, these results have not been confirmed and are still in dispute. Suspected links to breast cancer have not been borne out, nor have fears that PCBs can cause problems for infants who drink them in breast milk. GE customized its PCBs by processing raw materials brought in by rail. There is evidence that PCBs were spilled during each of several processing steps, but there was nothing illegal about this at the time. There are signs that fractured bedrock under the plants is still allowing some PCBs to leak into the Hudson River from sources on land or underground, but the PCB level has shown an overall downward trend since 1977.
Research is underway on other methods, including bioremediation by bacteria.
Fishing may be another problem. However, PCB concentrations in commercially sold fish are closely regulated, and anglers are warned to avoid fishing in the Hudson. Be that as it may, GE used PCBs only when they were legal, and only in ways that were legal. The materials were not believed to be hazardous at the time, nor could their potential hazards have been known in advance of their use. And there are lots of other PCBs around anyway.