Uptake and Disposition of Select Pharmaceuticals by Bluegill Exposed at Constant Concentrations in a Flow-Through Aquatic Exposure System.
The increasing use of pharmaceuticals has led to their subsequent input into and release from wastewater treatment plants, with corresponding discharge into surface waters that may subsequently exert adverse effects upon aquatic organisms. Although the distribution of pharmaceuticals in surface water has been extensively studied, the details of uptake, internal distribution, and kinetic processing of pharmaceuticals in exposed fish have received less attention. For this research, we investigated the uptake, disposition, and toxicokinetics of five pharmaceuticals (diclofenac, methocarbamol, rosuvastatin, sulfamethoxazole, and temazepam) in bluegill sunfish (Lepomis macrochirus) exposed to environmentally relevant concentrations (1000-4000 ng L-1) in a flow-through exposure system. Temazepam and methocarbamol were consistently detected in bluegill biological samples with the highest concentrations in bile of 4, 940, and 180 ng g-1, respectively, while sulfamethoxazole, diclofenac, and rosuvastatin were only infrequently detected. Over 30-day exposures, the relative magnitude of mean concentrations of temazepam and methocarbamol in biological samples generally followed the order: bile ≫ gut > liver and brain > muscle, plasma, and gill. Ranges of bioconcentration factors (BCFs) in different biological samples were 0.71-3960 and 0.13-48.6 for temazepam and methocarbamol, respectively. Log BCFs were statistically positively correlated to pH adjusted log Kow(that is, log Dow), with the strongest relations for liver and brain (r2= 0.92 and 0.99, respectively), implying that bioconcentration patterns of ionizable pharmaceuticals depend on molecular status, that is, whether a pharmaceutical is un-ionized or ionized at ambient tissue pH. Methocarbamol and temazepam underwent rapid uptake and elimination in bluegill biological compartments with uptake rate constants (Ku) and elimination rate constants (Ke) at 0.0066-0.0330 h-1and 0.0075-0.0384 h-1, respectively, and half-lives at 18.1-92.4 h. Exposure to mixtures of diclofenac, methocarbamol, sulfamethoxazole, and temazepam had little or no influence on the uptake and elimination rates, suggesting independent multiple uptake and disposition behaviors of pharmaceuticals by fish would occur when exposed to effluent-influenced surface waters.
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, P R China.
Jian-Liang
JL
Zhao
National Water Quality Laboratory, U.S. Geological Survey , Denver, Colorado 80225, United States.
Edward T
ET
Furlong
Aquatic Toxicology Laboratory, St. Cloud State University , St. Cloud, Minnesota 56301, United States.
Heiko L
HL
Schoenfuss
U.S. Geological Survey , Iowa City, Iowa 52240, United States.
Dana W
DW
Kolpin
Aquatic Toxicology Laboratory, St. Cloud State University , St. Cloud, Minnesota 56301, United States.
Kyle L
KL
Bird
Aquatic Toxicology Laboratory, St. Cloud State University , St. Cloud, Minnesota 56301, United States.
David J
DJ
Feifarek
National Water Quality Laboratory, U.S. Geological Survey , Denver, Colorado 80225, United States.
Eric A
EA
Schwab
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou 510640, P R China.
Guang-Guo
0000-0002-3387-1078
GG
Ying
D000818:Animals; D005399:Fishes; D010473:Perciformes; D013420:Sulfamethoxazole; D062065:Wastewater; D014874:Water Pollutants, Chemical
D013420:Sulfamethoxazole; D062065:Wastewater; D014874:Water Pollutants, Chemical