Acetaminophen (CAS 103-90-2) is one of the most used pharmaceuticals around the world. In Korea, it was produced 1,069 tons in 2003. This chemical is not eliminated in wastewater treatment plant and may flow into the ecosystem through various routes. Therefore, there is a possibility that it can make an adverse effect on aquatic organisms. To examine its ecological toxicity, we used three native Korean aquatic invertebrate species, Daphnia sp., Chironomus yoshimatsui, and Ephemera orientalis. The acute toxicity on Daphnia sp. was moderately high, and its 48 hour median immobilization concentration (EC50-immobilization) was 51.7 mg/L. On the other side, the reproductive toxicity was very high, and its EC50 of 25 day reproduction test was 0.005 mg/L. In E. orientalis egg hatching test, the median egg hatching inhibition concentration was 0.199 mg/L. C. yoshimatsui was most tolerant to acetaminophen, in which 48 hour median lethal concentration (LC50) was 400.0 mg/L and 45 day median emergence inhibition concentration (EC50-emergence) was 45.27 mg/L. From this results, we concluded that acetaminophen is hazardous to freshwater macroinvertebrates, especially to water flea. Therefore we need to study more about pharmaceuticals' ecotoxicology including acetaminophen and to assess their potential ecological risk.

This study investigated both leaching of heavy metals and ecological toxicity when coal bottom ash (CBA) generated by power plants has been used to reduce both erosion and turbidity of surface runoff at construction sites. The Korean leaching test (KLT) method, sequential extraction method, and acute toxicity test using Daphnia magna were performed to evaluate the environmental impacts and the ecological risks of CBA. According to the results of the KLT method of CBA, trace amounts of Cu were leached at limit of quantitation whereas metal leaching was not monitored for other heavy metals. Through the sequential extraction method of CBA, the relatively high leaching potential was found for As and Pb due to greater fraction of exchangeable (F1) and bound to carbonates (F2), and reasonable probability of leaching under the reducing/anaerobic environment was expected for Cu due to high faction of bound to Fe?Mn oxides (F3). However, significantly low probability of leaching was expected for Cd, Cr, Ni, and Zn with grater fractions of bound to organic matter (F4) and residual (F5). Additionally, total amount of heavy metals in CBA was lower than criteria for soil pollution concerns, and were similar or slightly lower levels than the ‘15 National soil average concentration excluding Cr6+. Finally, acute toxicity test using Daphnia magna display no impact for mobilization and lethality in either the prefiltration or post-filtration experiment, indicating that the ecological toxicity was insignificant with zero values of toxic unit. Consequently, no environmental impacts or ecological toxicity are expected when CBA generated by power plants has been used to reduce both erosion and turbidity of surface runoff at construction sites.