Publications by authors named "Dong-Hoon Im"

Triclosan, a chlorinated biphenyl ether is widely used in industrial products and cosmetics due to its antibiotic activity. Although relatively levels of triclosan have been detected in aquatic ecosystems, limited information is available regarding the acute and chronic impacts of triclosan on aquatic invertebrates, especially planktonic crustaceans. In this study, we analyzed the acute (24 h) and chronic (14 days exposure across three generations) effects of different concentrations of triclosan [1/10 of the no observed effect concentration (NOEC), the NOEC, and 1/10 of the LC50] calculated from the 24 h acute toxicity value, on the water flea Moina macrocopa.

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Article Synopsis
  • Marine microplastics (MPs), particularly polystyrene (PS), are ingested and egested by Pacific oysters (Crasostrea gigas), with a significant portion being retained after 7 days of exposure to 300 n/L of PS.
  • Ingestion peaked within 6 hours, with up to 60.4% of the PS ingested, while the maximum ingestion capacity was calculated at 73.0 n/g wet weight.
  • Smaller PS MPs (<50 μm) were found to have higher ingestion and egestion rates compared to larger sizes, suggesting that smaller particles pose a greater risk to human health via maricultural products, although depuration could mitigate this risk.
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We investigated spatiotemporal distributions of dissolved inorganic nutrients and organic carbon (DOC) and nitrogen (DON) in coastal waters and land-based fish farm wastewater to determine effects of wastewater on seawater of Jeju Island, Korea. The nutrient concentrations in seawater were lower than in wastewater with negative correlations against salinity, indicating a terrestrial source. Wastewater-derived DOC and DON were transported offshore while wastewater-derived inorganic nutrients were effectively removed, likely via biological production, and this was closely linked to decline in N:P ratios.

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We examined the residence time, seepage rate, and submarine groundwater discharge (SGD)-driven dissolved nutrients and organic matter in Hwasun Bay, Jeju Island, Korea during the occurrence of a typhoon, Kong-rey, using a humic fluorescent dissolved organic matter (FDOM)-Si mass balance model. The study period spanned October 4-10, 2018. One day after the typhoon, the residence time and seepage rate were calculated to be 1 day and 0.

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