Latitudinal distribution of OCPs in the open ocean atmosphere between the Argentinian coast and Antarctic Peninsula

Dissolved legacy and emerging organochlorine pesticides in the Antarctic marginal seas: Occurrence, sources and transport

Polar regions are recognized as final sinks of the persistent contaminants, however, environmental investigations in the Antarctica are greatly limited by harsh field conditions. In this study, seawater samples were collected in the Antarctic marginal seas during the austral summer of 2021 to investigate the environmental behavior and fate of organochlorine pesticides (OCPs). The concentrations and source markers of representative legacy hexachlorocyclohexane (HCH), hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethanes (DDTs) indicated the coexistent sources of historical residues and fresh inputs. While the emerging OCPs, including quintozene, pentachloroaniline and dichlobenil, showed relatively lower detection frequency. Due to the differences in temperature and sea ice coverage, dissolved OCPs generally displayed higher concentrations in the eastern Antarctic than those in the western Antarctic. The 'surface depleted and depth enrichment' vertical profile of representative OCPs in the continental shelf of Prydz Bay was jointly controlled by biological pump and water mass structure.

Assessment of organochlorine pesticides in the atmosphere of South Korea: spatial distribution, seasonal variation, and sources

Organochlorine pesticides (OCPs) are widely used in certain countries. We determined atmospheric concentrations, distribution patterns, and seasonal variations of OCPs at four sites in South Korea for 1 year. Samples of 22 OCPs were collected using a high-volume air sampler, and measured via the isotope dilution method with HRGC/HRMS. In South Korea, pentachlorobenzene (PeCB), hexachlorocyclohexane (HCB), and endosulfan (EnSF) were dominant, accounting for > 87% of total OCPs. Spatial distributions showed significant differences and the highest levels were observed in Seosan (295.2 pg·m^-3), indicating the compounding potential of diverse sources as Seosan has concentrated large-scale industrial complexes and agricultural activity (Seoul: 243.6 pg·m^-3 > Jeju: 193.5 pg·m^-3 > Baengnyeong: 178.2 pg·m^-3). The isomeric ratios of OCPs in the South Korean atmosphere indicated that the dominant sources of HCB and dichlorodiphenyltrichloroethane were primarily used in the past; meanwhile, chlordane (CHL) and EnSFs were derived from recent material inputs. Seasonally, OCP concentrations largely peaked in summer with minimum values in winter. This apparent temperature dependence suggests the re-volatilization of accumulated chemicals into the atmosphere. Additionally, an air mass back trajectory indicated the influence of pollutants released from a reservoir through long-range atmospheric transport in the summer. In particular, restricted OCPs are primarily released into the atmosphere by inadvertent sources, such as industrial activities and volatilization from contaminated areas. Thus, severe OCP pollution in Korea is due to the mobile nature of the particles. These data can be useful for the continuous monitoring of long-range transported air pollutants that are transferred between countries.

Bioaccumulation and Distribution Behavior of Endosulfan on a Cichlid Fish: Differences Between Exposure to the Active Ingredient and a Commercial Formulation

Persistent organic pollutants reach aquatic ecosystems during application and can bioconcentrate/biomagnify because of their lipophilic nature. Toxicological studies focus almost exclusively on the active ingredients of pesticides, instead of commercial formulations, whose toxicity can differ as a result of nonspecified ingredients. The intensive use of endosulfan as a wide-ranging insecticide over the last few decades makes it one of the most frequently detected contaminants in the aquatic environment, even after it has been restricted worldwide. The aim of the present study was to evaluate the bioaccumulation and organ distribution of waterborne endosulfan in the freshwater fish Cichlasoma dimerus, comparing the active ingredient and a commercial formulation. Males were exposed to 0.7 μg/L endosulfan for 2 wk, which was quantified (gas chromatography with an electron capture detector) in the liver, testes, gills, brain, and muscle. The results suggest rapid metabolism of α-endosulfan and β-endosulfan isomers to endosulfan sulfate (endosulfan-S) in tissues. Isomer levels were highest in gills, indicative of recent uptake. Levels of endosulfan-S were highest in liver and testes for the active ingredient and testes and brain for the commercial formulation. For the active ingredient, endosulfan-S levels showed a positive correlation with organ-lipid percentage. No correlation was evident for the commercial formulation, indicating that the presence of adjuvants alters endosulfan distribution because gills and liver showed a higher uptake and mobilization of β-endosulfan. These differences in organ distribution may alter tissue-specific toxicity; therefore, additives cannot be considered inactive even if nontoxic. Environ Toxicol Chem 2020;39:604-611. © 2019 SETAC.