Heavy metal accumulation in marine sediments is associated with changes in both the natural environment and human activities. This study used heavy metals and Pb isotopes in a precisely dated (by ²¹⁰Pb and ¹³⁷Cs) sediment core from the Macao Sea to reconstruct the historical changes in anthropogenic activities and the environment in the western Pearl River Estuary (PRE). The distribution of heavy metals in the sediment core could be divided into four stages (pre-1950, 1950–1976, 1976–2000, and post-2000), which corresponded to the changes in anthropogenic activities and environment of the Pearl River Delta during the past 100 years. The contribution of anthropogenic metals (Pb and Zn) in the sediments increased gradually over time. However, the concentrations, enrichment factors, and fluxes of heavy metals in the sediments all displayed a downward trend since 2010, revealing a decline in metal pollutant input due to strict emission reduction policies implemented in the last decade. The Pb isotopes in the sediments showed a similar trajectory to the heavy metals, reflecting the changes in Pb sources in the sediments at different stages. Based on a binary Pb isotope mixing model, the calculated proportions of anthropogenic and natural Pb in the sediments were 0–50.9% (mean 15.9%) and 49.1–100% (mean 84.1%), respectively, suggesting that the Pb in the PRE sediments is mainly controlled by natural sources.

海洋沉积物中的重金属积累与自然环境和人类活动的变化有关。本研究使用了精确年代的重金属和 Pb 同位素（由²¹⁰ Pb 和¹³⁷Cs) 澳门海沉积岩芯重建珠江口西部（PRE）人为活动和环境的历史变迁。沉积岩心重金属分布可分为四个阶段（1950年前、1950-1976、1976-2000和2000年后），与珠江三角洲人类活动和环境的变化相对应。过去的 100 年。随着时间的推移，沉积物中人为金属（铅和锌）的贡献逐渐增加。然而，沉积物中重金属的浓度、富集因子和通量自 2010 年以来均呈现下降趋势，表明由于近十年实施严格的减排政策，金属污染物输入量有所下降。沉积物中Pb同位素显示出与重金属相似的轨迹，反映了不同阶段沉积物中Pb来源的变化。基于二元 Pb 同位素混合模型，计算得出的沉积物中人为和天然 Pb 的比例分别为 0-50.9%（平均 15.9%）和 49.1-100%（平均 84.1%），表明 PRE 中的 Pb沉积物主要受自然资源控制。