2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/115924Although damped Lyman alpha (DLA) systems are usually considered metal-poor, it has been suggested that this could be due to observational bias against metal-enriched absorbers. I review recent surveys to quantify the particular issue of dust obscuration bias and demonstrate that there is currently no compelling observational evidence to support a widespread effect due to extinction. On the other hand, a small sub-set of DLAs may be metal-rich and I review some recent observations of these metal-rich absorbers and the detection of diffuse interstellar bands in one DLA at z ~ 0.5.5 pages, 3 figures. To appear in proceedings of "The Metal-Rich Universe", (La Palma, June 2006), eds. G. Israelian and G. Meynet (Cambridge Univ. Press)Astrophysicstext