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We examine the practice of deriving interstellar medium (ISM) abundances fromlow-resolution spectroscopy of GRB afterglows. We argue that the multi-ionsingle-component curve-of-growth analysis technique systematicallyunderestimates the column densities of the metal-line profiles commonlyobserved for GRB. This systematic underestimate is accentuated by the fact thatmany GRB line-profiles (e.g. GRB 050730, GRB 050820, GRB 051111) are comprisedof `clouds' with a bi-modal distribution of column density. Such line-profilesmay be characteristic of a sightline which penetrates both a high densitystar-forming region and more distant, ambient ISM material. Our analysissuggests that the majority of abundances reported in the literature aresystematically underestimates and that the reported errors are frequentlyover-optimistic. Further, we demonstrate that one cannot even report preciserelative abundances with confidence. The implications are profound for ourcurrent understanding on the metallicity, dust-to-gas ratio, and chemicalabundances of the ISM in GRB host galaxies. For example, we argue that all buta few sightlines allow for the gas to have at least solar metallicity. Finally,we suggests new approaches for constraining the abundances.Comment: 9 pages, 9 figures. Accepted to Ap

On the Perils of Curve‐of‐Growth Analysis: Systematic Abundance Underestimates for the Gas in Gamma‐Ray Burst Host Galaxies