Dust and metal column densities in GRB host galaxies

The immensely bright and intrinsically simple afterglow spectra of gamma-ray bursts (GRBs) have proven to be highly effective probes of the interstellar dust and gas in distant, star-forming galaxies. Despite significant progress, many aspects of the host galaxy attenuating material are still poorly understood. There is considerable discrepancy between the amount of X-ray and optical afterglow absorption, with the former typically an order of magnitude higher than what would be expected from the optical line absorption of neutral element species. Similar inconsistencies exist between the abundance of interstellar dust derived from spectroscopic and photometric data, and the relation between the line-of-sight and integrated host galaxy interstellar medium (ISM) remains unclear. In these proceedings we present our analysis on both spectroscopic and photometric multi-wavelength GRB afterglow data, and summarise some of the more recent results on the attenuation properties of the ISM within GRB host galaxies.