ABSTRACT Endogenous metabolism and environmental exposure can give rise to DNA adduct formation. Robust measurement of the levels of DNA adducts can offer important knowledge for understanding the mechanisms of DNA repair and allow for assessment of human exposure to genotoxic chemicals. We reason that a scheduled selected-reaction monitoring (SRM) method for DNA adduct analysis will facilitate high-throughput analysis of the DNA adductome. The long-term objective of this application is to develop a targeted DNA adductomic assay for assessing quantitatively the DNA adducts induced by various endogenous and exogenous sources of DNA damaging agents, and to employ the method for monitoring human exposure to complicated environmental pollutants and for investigating DNA repair. The proposed research is organized into three Specific Aims. In Aim #1, we will establish an SRM library for targeted quantitative measurement of the DNA adductome. In Aim 2, we will profile comprehensively the DNA adductome in lung tissues of mice exposed to particulate matter air pollution. In Aim 3, we will assess the oxidative metabolism and repair of alkylated DNA lesions by Fe2+- and 2- oxoglutarate-dependent oxygenases. The outcome of the proposed research will provide the scientific community with a high-throughput platform that allows for monitoring the DNA adductome and will afford novel insights about the repair of alkylated DNA lesions.