Investigation of potentially toxic heavy metals in different organic wastes used to fertilize market garden crops

► The organic waste population showed an asymmetric HM distribution. ► HM concentrations were mainly correlated with the size of cities or farms. ► HM were differentiated with respect to their origins. ► Cd-Cu-Zn-Pb were accumulated in fine size fractions and Cr-Ni in coarse fractions. ► Inorganic holding phases were detected for Cr-Ni and S or P species for Cd-Cu-Pb-Zn.