The researchers studied heavy metal pollution in the sediments of Jiulong River Estuary. They collected samples and measured levels of metals like copper, lead, and zinc. The results showed that the metals mainly came from the river runoff. Copper was found to be enriched beyond what the river brought in. Overall, the ecological risk in the estuary was low, and heavy metal pollution was not very severe during the study period. The sequence of pollution risk for the heavy metals in the area was lead, copper, cobalt, nickel, zinc, manganese, and chromium.