The requirement of venipuncture for obtaining blood samples in epidemiological research is a major challenge, especially with perinatal and pediatric populations. To address this challenge, we utilize DBS sampling—drops of whole blood collected on filter paper following a simple heel or finger stick—as a minimally-invasive and cost effective alternative to venous blood draws. In addition, newborn DBS samples are routinely collected from virtually all newborns in the United States to screen for inherited metabolic errors and other disorders, and several state public health departments archive residual newborn DBS and make them available for research. Thus, state-archived residual newborn DBS represent a large and important resource for epidemiological research. A main focus of our lab is the development and validation of both untargeted (discovery) and targeted biomarker methods for estimating environmental risk factors associated with adverse health outcomes.