Murine chronotoxicity to pharmaceutical wastewater

The present study was undertaken to report the modeling of the dosing-time-dependent adverse effects of both untreated and biologically-treated pharmaceutical wastewater in mice. The mice were housed in a room controlled at 24 °C under a 12 h/12 h dark-light cycle (light 7:00–19:00 h) for two weeks before initiating the experiments and allowed free access to food and water. A single dose of pharmaceutical or bioremediated effluent was administrated intraperitoneally (10 mL/kg) to mice divided in six circadian stages [1, 5, 9, 13, 17, and 21 hours after light onset (HALO)]. The surviving treated mice exhibited a significant circadian variation in body weight loss (p < 0.001). Pharmaceutical wastewater dosing at 17 HALO resulted in −6.5% weight loss, whereas drug dosing at 9 HALO was + 1.2% (Ф = 19.42 HALO ± 1.25 h, p < 0.01). Only on the dark span, the proportion of dead mice was dosing-time-dependent (χ2 = 12.7; p < 0.001). Pharmaceutical wastewater dosing at 17 HALO resulted in the poorest (67%) survival...