The present article examines the transport of species in streaming blood through a rigid artery in the presence of multi-irregular stenosis. The carrier fluid i.e., blood is assumed to be non-Newtonian fluid (Cassons viscoplastic model is used) and the arterial wall is considered to be rigid. A robust model is developed for non-Newtonian flow and hydrodynamic dispersion with the first-order chemical reaction on the arterial boundary in multiple irregular stenosed arterial geometries. Multiple scale solutions of the non dimensional boundary value problem are presented. Asymptotic expressions are developed for velocity and shear stress. Extensive visualization of velocity, concentration, and other flow characteristics is included for various stenotic scenarios, Péclet numbers, and Damköhler numbers. Significant modification in hemodynamic characteristics is computed with viscoplasticity. Mean concentration is also dramatically modified with yield stress and Péclet and Damköhler numbers. The study is relevant to arterial disease simulation.