Don't worry about it either way. PCBs are fairly benign to us, the problem is that they are extremely stable compounds so when they get into the ground water they stay there, over time this is a problem because you don't want to be drinking the stuff. It's a problem at scale though, millions of huge utility transformers, millions of tons of discarded consumer and industrial goods, that adds up. A handful of capacitors though? I wouldn't hesitate to have them in my house even if I knew they contained PCBs.