Comparison of column density ratios (with respect to that of C³⁴S) estimated in W49A and its subregions to those measured in the starburst galaxy M82 (Aladro et al. 2011b) and in the AGN NGC 1068 (Aladro et al. 2013). The error bars for HNCO and SiO toward M82 and those for H₂CO, H₂CS, and SO₂ toward NGC 1068 are an underestimate of the error bars for the ratios, as these values were calculated based on upper limits for the column densities.