Total and bioaccessible concentrations of arsenic (As) and lead (Pb), as well as their bearing phases in the adjacent soil area (residential area) of the historic and active Fe-oxide-rich mining district of Cerro de Mercado, Durango (Mexico), were evaluated. Results indicated the presence of arsenopyrite, galena, and As-bearing phases in ultrafine (\10 lm), fine (10-20 lm) and large (20-80 lm) particle sizes. Total concentrations ranged from 55 to 221 mg kg -1 As, near active and old tailings impoundments, exceeding 2.5-10 times the US EPA and ATSDR trigger level for residential soil remediation (20 mg kg -1 ). The corresponding bioaccessible fractions ranged from 0.7 to 18 %. Analyses by ATR-FTIR showed the presence of As sorbed onto iron-oxide-rich materials. Total Pb concentrations ranged from 22.3 to 107 mg kg -1 , below the US EPA trigger level (400 mg kg -1 ). The corresponding bioaccessible fractions ranged from 2.1 to 16 %. Total and bioaccessible results indicated that further studies of As are required whereas Pb bioaccessibility values were under the reference concentrations established by Mexican guidelines for implementing a remediation strategy, suggesting that environmental impact occurs mainly for As. Arsenic and Pb dispersion from their pollution sources (historic and active tailing impoundments, waste rock dumps), was mainly associated with airborne particles transport in SW-NE direction impacting the adjacent soil area at the Cerro de Mercado mining district. Finally, an environmental impact assessment should be done in the studied area.