Additional file 1: Table S1. Cu, Zn. Pb, Co, and Ni concentrations in the exchangeable fraction extracted by 1M NH4Cl and their proportion (%) in the acid-soluble fraction extracted two times with 0.11M acetic acid (Hac) of ten selected samples. Table S2. Bulk Cu, Zn, Pb, Co, and Ni concentrations and δ66Zn values of samples analyzed for Zn stable isotopes of the core OS5B. *ND: not determined. Fig. S1. Catchment of Osaka Bay (bold black line) with prefectural boundaries (thin black lines) and location of the sediment cores collected at station OS5B. Fig. S2. Swampy lowlands during the early Meiji era. Source: Technical Report of the Geospatial Information Authority of Japan (Technical Report D1-No.633, Marsh data in the early Meiji Era (Kinki District)). Fig. S3. Comparison of total organic carbon (TOC) and total nitrogen (TN) concentrations between the piston core and the multi core. Fig. S4. Time profiles of the enrichment factor (EF) of Zn, Cu, Pb, Ni, and Co in the piston core during the last 2300 years. *Azuchi-Momoyama period. Fig. S5. Time profiles of the chemical index of alteration (CIA) calculated from the residual fraction (F4). *Azuchi-Momoyama period. Fig. S6. Biplots of trace metal concentrations against chemical index of alteration (CIA) calculated from the residual fraction (F4). Fig. S7. Time profiles of the Zn contribution estimated based on a simple binary mixing model following equation (3).