Q-16: A reader was confused by the term "PCB" that he had seen in several magazine articles. He thought the reference was to the toxic substance material known as Polychlorinated Biphenyls.
A-16: The abbreviation was probably referring to a printed circuit board. For many years it was referred to as a "PC board." This is a plastic board that contains copper foil strips to interconnect electrical components that are mounted on it. I've recently seen the reference change to "PCB," hence the dual meaning.