Biological effects of PPCPs on aquatic lives and evaluation of river waters affected by different wastewater treatment levels.

The existence of pharmaceuticals and personal care products (PPCPs) in the water environment is an emerging problem. In this study, we investigated the toxicity of eleven PPCPs through bioassays on bacteria, algae, crustaceans, amphibians and protozoa, and compared the toxicology indexes with the concentration of PPCPs in river water for ecotoxiclogical risk evaluation. Toxicity of the eleven PPCPs was observed and the values of EC50 or LC50 were in the order of mg/L. A distinctive finding is that antibacterial triclosan affected all aquatic lives tested. The effects of PPCPs varied according to species of lives. Contamination from PPCPs was detected at observation stations on the river, and the range of concentration was in the order of ng/L far lower than the values of toxicity indexes EC50 or LC50. Ecotoxicological risks posed by PPCPs at the observation stations was evaluated using the concentration in the river water and the NOEC examined by AGI tests. The results revealed that three PPCPs, triclosan, clarithromycin, and azithromycin, posed an ecotoxiclogical risk in rivers where wastewater treatment systems are not yet well developed.

Fate estimation of estrogenic substances in an urban river by flux calculation.

This study investigated the fate of estrogenic substances in an urban river receiving discharge from wastewater treatment plants (WTPs) by flux calculation, focusing on the middle reaches of the Tama River in Tokyo, which is one of the most urbanized rivers in Japan. The level of estrogenic activity flux was almost negligibly small at the upstream station. The level was considerably raised after inflows from the WTPs and then the level declined in the lower reaches of the river. When contributions of estrogenic substances to estrogenic activity were estimated, estrone (E1) was the primary contributor to the total estrogenic activity in all the sampling stations, followed by estradiol (E2). The contribution of nonylphenol to estrogenic activity was small. The E1 and E2 accounted for approximately 90% or more of estrogenic activity in the Tama River. As for the total fluxes of the estrogenic substances in the study area in the Tama River, the proportion of flux associated with WTP discharge was approximately 100% of the total fluxes, and the effects of the tributaries flowing into the river were almost negligible. When the reduction ratios of estrogenic activity were calculated by the flux, the ratios were found to increase toward the lower reaches of the river. Similar changes were observed for E1. Meanwhile, the change of reduction ratios for E2 was different from that observed for estrogenic activity.

Occurrence and fate of anti-inflammatory drugs in wastewater treatment plants in Japan.

The fates of anti-inflammatory drugs (e.g., ibuprofen, naproxen, mefenamic acid and ketoprofen), which are frequently detected in the discharges of wastewater treatment plants (WWTPs) and river water in Japan, were clarified in two WWTPs. The concentrations of ibuprofen, naproxen, mefenamic acid and ketoprofen were 69-1080, 179-305, 143-1580 and 160-1060 ng/L in the influent, and N.D. (< 40 ng/L), 74-166, 72-265, 64-107 ng/L in the effluent, respectively. The concentrations of the anti-inflammatory drugs analyzed were almost equal to or lower than those reported in foreign countries. High removal efficiencies of the drugs, except ibuprofen, were observed in the WWTP that has longer hydraulic retention time than that of the other WWTP. For ibuprofen, high removal efficiencies were observed in both WWTPs (84 to 98%). Disinfection by chlorination was not effective to remove the drugs surveyed. On the other hand, the effective removal of ketoprofen by ultraviolet (UV) radiation for disinfection was demonstrated, although the disinfection by-products were not identified.