Comparison between the metallicity values obtained for the SFRs by our analysis (in red) and other very young tracers of the present-day radial metallicity gradient: O and B-type stars (black symbols), red supergiants (RSGs; blue and green symbols), and Hii regions (yellow symbols). For the RSGs and SFRs we assumed the [Fe/H] values as metallicity determinations, while for the O and B-type stars and Hii regions we adopted the log(O) + 12 scaled by 8.66 dex, the mean solar abundance of oxygen taken from Grevesse et al. (2007).