Linkages between population demographics and municipal effluent estrogenicity.
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Biomedical subjects
Publications and source records attributed to D B Huggett.
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Beta adrenergic receptor antagonists (beta-Blockers) are frequently prescribed medications in the United States and have been identified in European municipal wastewater effluent, however no studies to date have investigated these compounds in United States wastewater effluent. Municipal wastewater effluent was collected from treatment facilities in Mississippi, Texas, and New York to investigate the occurrence of metoprolol, nadolol, and propranolol. Propranolol was identified in all wastewater samples analyzed (n = 34) at concentrations < or = 1.9 microg/l. Metoprolol and nadolol were identified in > or = 71% of the samples with concentrations of metoprolol < or = 1.2 microg/l and nadolol < or = 0.36 microg/l. Time course studies at both Mississippi plants and the Texas plant indicate that concentrations of propranolol, metoprolol, and nadolol remain relatively constant at each sampling period. This study indicates that beta-Blockers are present in United States wastewater effluent in the ng/l to microg/l range.
One class of pharmaceutical compounds identified in U.S. and European waters are the B-adrenergic receptor blocking compounds (B-blockers). However, little information is available on the potential aquatic toxicity of these compounds. Therefore, Hyalella azteca, Daphnia magna, Ceriodaphnia dubia, and Oryias latipes (Japanese medaka) were exposed to metoprolol, nadolol, and propranolol to determine potential toxicity. Average 48-h LC(50) for propranolol to H. azteca was 29.8 mg/L. The no-observed-effects concentration (NOEC) and lowest-observed-effects concentration (LOEC) for propranolol affecting reproduction of H. azteca were 0.001 and 0.1 mg/L, respectively. The average propranolol and metoprolol 48-h LC(50)s for D. magna were 1.6 and 63.9 mg/L, respectively. C. dubia 48-h LC(50)s were 0.85 and 8.8 mg/L for propranolol and metoprolol, respectively. The NOEC and LOEC of propranolol affecting reproduction in C. dubia were 0.125 and 0.25 mg/L, respectively. In O. latipes, the propranolol 48-h LC(50) was 24.3 mg/L. Medaka growth was decreased at 0.5 mg/L propranolol. A 2-week medaka reproductive study indicated significant changes in plasma steroid levels; however, no changes in the average number of eggs produced or number of viable eggs which hatched was observed. In a 4-week follow-up propranolol exposure, the total number of eggs produced by medaka and the number of viable eggs that hatched were decreased at concentrations as low as 0.5 microg/L. Based on this study and the expected aqueous environmental exposure levels, adverse effects of propranolol to invertebrate populations is unlikely; however, further reproductive studies are need to elucidate the risk to teleosts.
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The vascular macrophyte Typha latifolia Linnaeus (common cattail) may be a sentinel for evaluating potential phytotoxicity to rooted aquatic macrophytes in aquatic systems. To further evaluate the potential utility of this species, T. latifolia seed germination, shoot growth, and root elongation were measured in 7-day aqueous exposures using mean measured aqueous copper concentrations of 10.0, 23, 41, 62, 174, and 402 microg Cu/L, which were > or = 62% of nominal concentrations. Seed germination and seedling shoot growth were not significantly affected by any of these copper concentrations as compared to controls. Mean measured no-observed-effect-concentration (NOEC) and lowest-observed-effect-concentration (LOEC) for root elongation were 18.6 microg Cu/L and 35.0 microg Cu/L, respectively. Seven-day sediment tests were conducted by amending uncontaminated sediments with copper sulfate to mean measured concentrations of 7.9, 17.1, 21.0, 51.2, 89.5, and 173.5 mg Cu/kg, which were > or = 84% of nominal concentrations. Seed germination was not significantly different from controls. Mean measured NOEC and LOEC values for seedling shoot growth were 89.5 mg Cu/kg and 173.5 mg Cu/kg, respectively, and mean measured NOEC and LOEC values for root growth were 14.0 mg Cu/kg and 19.7 mg Cu/kg, respectively. These results demonstrate that T. latifolia early seedling growth can be utilized for assessing aqueous and sediment toxicity of copper.
Fipronil is a phenylpyrazole insecticide that is the active ingredient in the pesticide Icon 6.2 FS which is applied to rice seeds targeting the rice water weevil. An arthropod-selective insecticide, fipronil blocks the GABA-gated chloride channel and is unique in that several of its degradation products have been indicated to be equal or more potent than fipronil. After application of rice seeds (2-3 days postplant) to flooded rice fields, water is typically pumped from the rice fields and can be used for the culture of crayfish (Procambarus sp.). Because fipronil is selective for arthropods, is transported via organic sediment, and crayfish consume organic sediment, 96-h LC(50) experiments were conducted with fipronil and three of its environmental derivatives in crayfish under conditions without carrier solvents in water of similar pH, alkalinity, and hardness as observed in south Louisiana crayfish culture ponds. Measured LC(50)s for fipronil to red swamp (Procambarus clarkii) and white river (Procambarus zonangulus) crayfish were 14.3 (95% CI; 5.1-23.4) and 19.5 (95% CI; 11.1-27.9) microg/L, respectively. LC(50)s of fipronil sulfone (11.2; 9.2-13.2 microg/L), fipronil sulfide (15.5; 13-18 microg/L); and the photoproduct, desulfinyl fipronil (68.6; 46-95.2 microg/L) displayed very high toxicity in crayfish. In situ toxicity studies using caged crayfish in culturing ponds receiving effluent from drained rice fields indicated that effluent from rice fields planted with Icon-treated seed was significantly more toxic compared to untreated surface water (40% survival compared to 83% survival). Hazard quotient comparisons using measured water concentrations in the field and laboratory-based LC(50)s indicated that fipronil and its metabolites in water resulting from Icon-treated rice seed planting poses a significant risk to crayfish survival.
Sediments and/or fish were collected from Sardis, Enid and Grenada Lakes, which are located in three different watersheds in North Mississippi, in order to assess mercury contamination. The mean total mercury concentration in sediments from Enid Lake in 1997 was 0.154 mg Hg/kg, while 1998 sediment concentrations in Sardis, Enid and Grenada Lakes were 0.112, 0.088 and 0.133 mg Hg/kg, respectively. Sediment mercury concentrations in 1999 were similar in all three lakes but, generally lower than 1998. Mean total mercury concentrations in edible fillets of fish collected from Enid Lake in 1998 were above the human health FDA action level (> 1.0 mg Hg/kg) for bass (1.40), crappie (1.69) and gar (1.89); however, tissue concentrations were less than 1.0 mg Hg/kg in carp (0.63) and catfish (0.82). Human hazard indexes for each species was > or = 1 for both adults and children, indicating that there is a potential for toxic effects to occur. In addition, calculated consumption limits indicate that adults may consume 4-12 oz. of fish per month, depending on the species consumed. For children, 2 oz. per month may be consumed. Further studies are needed to determine the exact environmental consequences and human health impacts associated with mercury contamination in North Mississippi and the Southeastern United States.
Sediments were collected from a stream (upstream, outfall and downstream) receiving copper laden catfish pond effluent to assess toxicity to non-target biota. No significant reduction in Hyalella azteca survival or growth (10 d), or Typha latifolia germination and root and shoot growth (7 d) were observed after exposure to upstream and outfall sediments. A significant reduction in H. azteca survival was observed after exposure to the downstream sediment sample; however, no reduction in T. latifolia germination or seedling growth was detected. Bulk sediment copper concentrations in the upstream, outfall and downstream samples were 29, 31, and 25 mg Cu/kg dry weight, respectively. Interstitial water (IW) concentrations ranged from 0.053 to 0.14 mg Cu/l with 10 d IW toxicity units > or = 0.7. Outfall samples were amended with additional concentrations of copper sulfate so that bulk sediment measured concentrations in the amended samples were 172, 663, 1245, and 1515 mg Cu/kg dry weight. Survival was the most sensitive endpoint examined with respect to H. azteca with a no observed effects concentration (NOEC) and lowest observed effects concentration (LOEC) of 1245 and 1515 mg Cu/kg, respectively. NOEC and LOEC for T. latifolia root growth were 663 and 1245 mg Cu/kg, respectively. IW copper concentrations were > or = 0.86 mg Cu/l with H. azteca intersitial water toxicity unit (IWTU) concentrations > or = 1.2. Sequential extraction qualitatively revealed the carbonate and iron oxide fractions which accounted for a majority of the copper binding. In this instance, the copper which was applied to catfish ponds does not appear to be adversely impacting the receiving stream system.
Sediments were collected from Steilacoom Lake, Pierce County, in Washington State, and amended with copper sulfate (nominal concentrations of 800, 1,000, 1,500, and 2,000 mg Cu/kg dry weight) to assess copper bioavailability to Hyalella azteca, Chironomus tentans, or Ceriodaphnia dubia. H. azteca survival and C. tentans survival and growth were not significantly affected, with 10-day no observed effects concentrations (NOEC) and lowest observed effects concentrations (LOEC) of 2,010 and >2,010 mg Cu/kg, respectively. C. dubia was the most sensitive organism tested with 10-day NOEC and LOECs for survival and reproduction of 906 and 1,469 mg Cu/kg, respectively. Sediment AVS concentrations were <0.15 micromol/g, while simultaneously extracted metal (SEM) concentrations were >/=5. 71 micromol Cu/g. Dissolved interstitial water concentrations ranged from below detection (0.010 mg/L) to 0.24 mg Cu/L, with interstitial water toxicity units as high as 3.4. Based on this study, effects to C. dubia may occur at bulk sediment concentrations >906 mg Cu/kg. Further, AVS and interstitial water concentrations are not accurate predictors of copper bioavailability in Steilacoom Lake.
Copper sulfate (CuSO4) is applied periodically to commercial channel catfish (Ictalurus panctatus) ponds as an algicide or parasiticide. Current understanding of the chemistry of copper in soil-water systems suggests that copper may accumulate in pond sediments, although the forms and potential bioavailability of copper in catfish pond sediments are not known. This study investigated the accumulation and distribution of copper in the sediment of catfish ponds receiving periodic additions of CuSO4.5H2O. All ponds were constructed in Sharkey (very-fine, smectitic, thermic Chromic Epiaquert) soil. Nine 0.40-ha ponds received 59 applications of 2.27 kg CuSO4.5H2O per application per pond over 3 yr; no CuSO4.5H2O applications were made to nine additional ponds. Total Cu concentration in the sediments of CuSO4.5H2O-amended catfish ponds (172.5 mg kg(-1)) was four to five times higher than that in the sediments of nonamended ponds (36.1 mg kg(-1)). Copper accumulated in catfish pond sediments at a rate of 41 microg kg(-1) dry sediment for each 1 kg ha(-1) of CuSO4. 5H2O applied to ponds. Copper in the sediments of amended ponds was mainly in the organic matter-bound (30.7%), carbonate-bound (31.8%), and amorphous iron oxide-bound (22.1%) fractions with a considerable fraction (3.4%; 3 to 8 mg kg(-1)) in soluble and exchangeable fractions. This indicates that Cu accumulates differentially in various fractions, with proportionally greater initial accumulation in potentially bioavailable forms. However, toxicity bioassays with amphipods (Hyallela azteca) and common cattail (Typha latifolia L.) indicated that the effect of exposure to amended or nonamended pond sediments was not different.