How do Dan and Randy figure out where the illness is coming from?

They stop at the Hernandez house where Rita greets them. He is amazed by the merchandise in the two front rooms of the house. Randy asks if they're in the junk business but Rita says it's her investment. She believes things will get better and shows him her new diamond ring. When she slips it off he notices the dark, black circle around her finger. Randy drops it when she says it's from Porky. Dan examines her finger and she says Porky got the ring, watches and other jewelry from an abandoned shop in the Miami area. Dan and Randy determine the jewelry and watches are radioactive from fallout and suicidal to wear. They insist Pete take off the watches he wears and tell him they're radioactive. Pete takes out a toilet kit full of jewelry from under his pillow.