Heavy Metals in Lingdingyang Sediments: Where Pollution Lives and How It Affects Us

The study looked at 132 samples of the top layer of sea mud near Lingdingyang, a busy industrial spot in China’s Greater Bay Area. It measured seven heavy metals: copper, zinc, lead, chromium, cadmium, mercury and arsenic. Researchers used a mild acid test to find out how much of each metal could be easily released into the water. They also compared total amounts with those that are most mobile, because only the mobile part can harm living things. The results showed big differences from north to south. Copper, zinc, chromium and cadmium were most concentrated in the northern parts of the bay. The worst spots were near Jiaoyi Bay, the Maozhou River mouth and two nearby industrial parks. Four main pollution sources were identified.

About 38% came from old PCB factories and metal‑plating plants. Nearly 27% were linked to electronics and chemical makers. Historical coal burning contributed about 19%. The rest, around 17%, came from natural rock weathering. Many of the metals that can be released quickly were also found in high total amounts, especially cadmium, copper and zinc. About 10% of the stations were flagged as priority control sites because they pose serious risks. Copper mainly threatens non‑cancer health, while cadmium raises cancer concerns for people who live or work nearby. The study fills a gap in knowledge about this heavily used coastal area and gives clear data for governments to plan cleanup actions.

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