Isotopic characteristics of antifouling paints and fractionation of Cu and Zn isotopes during dissolution by seawater and their adsorption to marine sediments.

The elemental and isotopic (δCu and δZn) characteristics of 34 AFP samples from 5 paint manufacturers, the isotopic fractionation during the dissolution of AFPs by seawater, and the subsequent adsorption of isotopes onto coastal fine-grained sediments were investigated to identify potential indicators (metal ratios and isotopes). The δCu and δZn values for 34 AFPs could be divided into 2 groups regardless of the type of paint or manufacturer. Dissolution by seawater induced substantial fractionation but δCu and δZn approached the bulk AFP values when the leached fraction increased.

In-situ δO and Sr/Sr proxies in an unconformable clastic unit at the Ordovician-Silurian transition.

Clastic successions found in the carbonate platform of continental margin during the Ordovician-Silurian Transition (OST) period are archives for interpreting paleo-depositional systems. Here, we report in-situ δO and Sr/Sr isotope chemo-stratigraphy for an unconformable clastic unit from the Cathaysia terrane that rifted off the Gondwana Supercontinent in the Early Paleozoic Era. Our results suggest a depositional proxy and model for geological events attributed to rapid changes in the sedimentary environment during the OST period.

Recent pollution and source identification of metal(loid)s in a sediment core from Gunsan Reservoir, South Korea.

We assessed the contributions of Cu smelting and Asian dust influx to metal(loid) pollution over the last century based on metal(loid) concentrations, Pb isotope ratios, and Pb dating of sediments from Gunsan Reservoir, South Korea. During the pre-industrial period (1827-1936), heavy metal pollutants were predominantly geogenic. Local smelting activity was dominant between 1936 and 2008.

Lead isotopes combined with geochemical and mineralogical analyses for source identification of arsenic in agricultural soils surrounding a zinc smelter.

As-contaminated soil samples were chosen to identify As sources near a Zn smelter where Zn contamination in soils was found to be of smelter origin. Based on the As concentrations and Pb isotopic compositions, high As levels in soils were originated from the geogenic source. There was no consistent trend in As concentrations with either depth or distance from the smelter, while the Pb isotopic compositions in soils varied regardless of As levels and were quite different from those of smelter origin.

Source identification of arsenic contamination in agricultural soils surrounding a closed Cu smelter, South Korea.

Arsenic sources were identified in As-contaminated soils 4 km-7 km from a closed Cu smelter. Host rocks, heavy minerals in contaminated soils, ore minerals in quartz veins (geogenic sources) and bottom ash from the Cu smelter (an anthropogenic source) were investigated as potential sources. As a result, heavy minerals and bottom ash were found to contain higher As concentrations than the contaminated soils.

Determining the geographical origin of Chinese cabbages using multielement composition and strontium isotope ratio analyses.

Recently, the Korean market has seen many cases of Chinese cabbage (Brassica rapa ssp. pekinensis) that have been imported from China, yet are sold as a Korean product to illegally benefit from the price difference between the two products. This study aims to establish a method of distinguishing the geographical origin of Chinese cabbage.