Heavy metal characterization of land-based waste dumped at three ocean dumping sites in the Republic of Korea

Abstract

From 1991 to 2021, 16 categories of land-based waste, totaling 131,400,000 m3, were dumped at three sites in Korea. The concentration of heavy metals varied by waste type, with organic sludge showing higher levels than liquid waste. While wastewater treatment sludge was the most commonly discarded waste, the quantity and types of waste disposed of varied by site. Before the 2015 ban on ocean dumping, 62,330 tons of heavy metals were introduced, including zinc, copper, chromium, lead, arsenic, cadmium, and mercury in descending order of frequency. In each heavy metal category, the portion of land-based waste varied by dumping site. Compared to heavy metals from atmospheric deposition, anthropogenic heavy metal input from dumping was up to 141 times higher for copper. This study serves as a reference for estimating the impact of pollutants from dumped waste.