Campen received a BS in biochemistry from Virginia Tech in 1994 and a Master of Science in Public Health concentrating on environmental health from the University of North Carolina at Chapel Hill, in 1997. He received his PhD, in environmental health from UNC Chapel Hill in 2000 followed by a postdoctoral fellowship at the Johns Hopkins University School of Medicine. Prior to his current appointment, he worked as an independent scientist at the Lovelace Respiratory Research Institute in Albuquerque.