Assessment of Metal Contents and Lead Isotope Fingerprints in South China Sea Seawater and Sediments

To investigate both anthropogenic and natural sources of metals in the South China seawater, the study analyzed metal content and Pb isotopic compositions in surface sediment and seawater from Taiwan and Indonesia. This analysis aimed to assess potential environmental pollution in the region. Samples were leached using a microwave digestion technique, and concentrations of metals (Na, Mg, Al, Si, K, Ti, Ca, Fe, and Pb), as well as Pb isotopes (207Pb/204Pb and 208Pb/204Pb), were measured using inductively coupled plasma-mass spectrometry (ICP-MS). Metal concentrations in sediment ranged from lowest to highest: Na at 0.4-3.8 % At, Mg at 0.6-1.2 % At, Al at 4.2-7.3% At, Si at 14.4-20.6% At, K at 0.7-1.8% At, Ti at 0.3-0.4% At, Ca at 0.2-1.1% At, and 1.3-2.0% Fe At. all up the background levels set by the World Health Organization (WHO). Pb isotope ratios in surface seawater ranged from 208Pb/204Pb = 0.1530–0.2107, indicating alignment with the total Pb concentration and suggesting that Pb originated from natural sources associated with the sediment and seawater.