[Show abstract][Hide abstract] ABSTRACT: Concentrations and distributions of selected fluoroquinolones (norfloxacin, ciprofloxacin and enrofloxacin) in water, sediments and nine kinds of fish species collected from 6 sites in two marine aquaculture regions of the Pearl River Delta, China, were analyzed by using high-performance liquid chromatography with fluorescence detector (HPLC). The results showed that the concentrations of ciprofloxacin and enrofloxacin were below the limits of quantification (LOQ) in all water samples except for norfloxacin. Norfloxacin and ciprofloxacin concentrations ranged from 1.88 to 11.20 ng g(-1) dry wt, 0.76-2.42 ng g(-1) dry wt in sediments collected from the Dapeng'ao region (sites 1-3) and ranged from 2.31 to 4.75 ng g(-1) dry wt, 1.26-1.76 ng g(-1) dry wt in sediments collected from the Hailing Island region (sites 4-6), respectively. However, no enrofloxacin was found in all sediment samples. The three fluoroquinolones (FQs) were detected in all fish samples, and the concentrations were higher in liver tissues than those in muscle tissues. The levels of norfloxacin were higher than ciprofloxacin and enrofloxacin in both liver and muscle tissues. Among the nine marine fish species, Siganus fuscescens from Hailing Island had a significantly high level of norfloxacin in liver tissue (254.58 ng g(-1) wet wt), followed by Sparus macrocephalus (133.15 ng g(-1) wet wt) from Dapeng'ao, and the lowest value was Lutianus argentimaculatus (5.18 ng g(-1) wet wt) from Hailing Island. The obtained results of FQs in present study do not represent a risk to the human health in Guangdong coastal area, based on the maximum residue limits (MRLs) established by Chinese Government and the acceptable daily intake (ADI) recommended by the Food and Agriculture Organization and World Health Organization (FAO/WHO).
Full-text · Article · Sep 2011 · Environmental Geochemistry and Health
[Show abstract][Hide abstract] ABSTRACT: The toxic effects of norfloxacin (NOR) and butylated hydroxyanisole (BHA) on the microalga Scenedesmus obliquus were assessed in terms of growth rate, concentration of chlorophyll a, activities of 7-ethoxyresorufin-o-dealkylases (EROD), glutathione s-transferase (GST), catalase (CAT) and total malondialdehyde content (MDA). The 96 h EC(50) was 38.49 and 11.12 mg/l for NOR and BHA, respectively. Growth of S. obliquus was affected slightly under low concentrations of BHA (<4 mg/l) and NOR (<15 mg/l) over the 96 h exposure period. With the increasing concentrations of these two compounds, growth of S. oblique decreased significantly. Growth inhibition was 82.4% at 60.0 mg/l for NOR and 60.6% at 16.0 mg/l for BHA after 96 h. A similar trend was also observed for chlorophyll alpha. NOR and BHA affected Phase I and Phase II enzyme activities differently. Upon exposure to NOR, EROD was induced at concentration <15.0 mg/l and depressed at concentrations >30 mg/l significantly. CAT and GST exhibited similar trends during the exposure period. Compared to controls, MDA content only showed high induction at high concentrations of NOR (>30 mg/l). However, EROD activity did not display any change compared to control responses during BHA exposure, whereas GST showed significant induction for all concentrations over the exposure period. CAT activity showed induction at low concentration and depression at high concentration. MDA content increased with the rise of BHA during the exposure period. These types of assays, revealing toxic effects of NOR and BHA to phototrophs, could be employed to assess the potential risks of these xenobiotics to aquatic ecological systems.