In the present investigation, the most commonly used pharmaceutical drug Ibuprofen (IB) was exposed to an Indian major carp Cirrhinus mrigala under static bioassay method to estimate its toxicological effects for a period of 35 days. The median lethal concentration (LC 50) of IB to the fish C. mrigala for 24 h was found to be 142 ppm. In sublethal treatment (1/10th of LC 50 24 h value, 14.2 ppm), a significant decrease in erythrocyte (RBC), mean cellular hemoglobin concentration (MCHC) and plasma protein levels were observed throughout the study period when compare to that of their respective controls. In contrast, haemoglobin (Hb), hematocrit (Hct), mean cellular volume (MCV), mean cellular hemoglobin (MCH), leucocyte (WBC), plasma glucose and alanine transaminase (ALT) levels were increased in this study period. On the other hand, a mixed trend was noticed in aspartate aminotransaminase (AST) enzyme activity. Alterations of these parameters can be effectively used as potential biomarkers in monitoring of IB toxicity in the aquatic organisms.

http://dx.doi.org/10.1016/j.etap.2012.02.005

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Antimicrobials used in poultry production have the potential to bioaccumulate in poultry feathers but available data are scarce. Following poultry slaughter, feathers are converted by rendering into feather meal and sold as fertilizer and animal feed, thereby providing a potential pathway for reentry of drugs into the human food supply. We analyzed feather meal (n = 12 samples) for 59 pharmaceuticals and personal care products (PPCPs) using EPA method 1694 employing liquid chromatography tandem mass spectrometry (LC/MS/MS). All samples tested positive and six classes of antimicrobials were detected, with a range of two to ten antimicrobials per sample. Caffeine and acetaminophen were detected in 10 of 12 samples. A number of PPCPs were determined to be heat labile during laboratory simulation of the rendering process. Growth of wild-type E. coli in MacConkey agar was inhibited by sterilized feather meal (p = 0.01) and by the antimicrobial enrofloxacin (p < 0.0001) at levels found in feather meal. Growth of a drug-resistant E. coli strain was not inhibited by sterilized feather meal or enrofloxacin. This is the first study to detect antimicrobial residues in feather meal. Initial results suggest that more studies are needed to better understand potential risks posed to consumers by drug residues in feather meal.

DOI: http://dx.doi.org/10.1021/es203970e

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The mobility and bioavailability of cadmium, copper, lead and zinc were evaluated in three soils amended with different organic materials for two moisture regimes. Agricultural and reclamation activities impose fresh inputs of organic matter on soil while intensive irrigation and rainstorm increase soil waterlogging incidence. Moreover, scarcity of irrigation water has prompted the use of greywater, which contain variable concentrations of organic compounds such as anionic surfactants.

Soils added with hay, maize straw or peat at 1% w/w were irrigated, at field capacity (FC) or saturated (S), with an aqueous solution of the anionic surfactant Aerosol 22 (A22), corresponding to an addition of 200 mg C/kg soil/day. Soil solution was extracted after one month and analysed for total soluble metals, dissolved soil organic matter and UV absorbance at 254 nm. Speciation analyses were performed with WHAM VI for Cd, Cu, Pb, and Zn. For selected scenarios, metal uptake by barley was determined.

Metal mobility increased for all treatments and soils (Pb > Cu > Cd ≥ Zn) compared to control assays. The increase was significantly correlated (p < 0.05) with soil organic matter solubilisation for Cd (R = 0.68), Cu (R = 0.73) and Zn (R = 0.86). Otherwise, Pb release was related to aluminium solubilisation (R = 0.75), which suggests that Pb was originally co-precipitated with Al–DOC complexes in the solid phase. The effect of A22 in metal bioavailability, determined as free ion activities (FIA), was mainly controlled by soil moisture regime. For soil 3, metal bioavailability was up to 20 times lower for soil amended with hay, peat or maize compared to soil treated only with A22. When soil was treated with A22 at FC barley yield significantly decreased (p < 0.05) for the increase of Pb (R = 0.71) and Zn (R = 0.79) concentrations in shoot, while for saturated conditions such uptake was up to 3 times lower.Overall, metal bioavailability was controlled by solubilisation of soil organic matter and formation of metal-organo complexes.

http://dx.doi.org/10.1016/j.scitotenv.2012.02.033

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Approaches are needed to better predict spatial variation in riverine Hg concentrations across heterogeneous landscapes that include mountains, wetlands, and open waters. We applied multivariate linear regression to determine the landscape factors and chemical variables that best account for the spatial variation of total Hg (THg) and methyl Hg (MeHg) concentrations in 27 sub-basins across the 493 km2 upper Hudson River basin in the Adirondack Mountains of New York. THg concentrations varied by sixfold, and those of MeHg by 40-fold in synoptic samples collected at low-to-moderate flow, during spring and summer of 2006 and 2008. Bivariate linear regression relations of THg and MeHg concentrations with either percent wetland area or DOC concentrations were significant but could account for only about 1/3 of the variation in these Hg forms in summer. In contrast, multivariate linear regression relations that included metrics of (1) hydrogeomorphology, (2) riparian/wetland area, and (3) open water, explained about 66% to >90% of spatial variation in each Hg form in spring and summer samples. These metrics reflect the influence of basin morphometry and riparian soils on Hg source and transport, and the role of open water as a Hg sink. Multivariate models based solely on these landscape metrics generally accounted for as much or more of the variation in Hg concentrations than models based on chemical and physical metrics, and show great promise for identifying waters with expected high Hg concentrations in the Adirondack region and similar glaciated riverine ecosystems.

doi: http://dx.doi.org/10.1029/2011JG001812

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At four locations in and around Monterey Bay, California, the researchers, using equipment that slurps up large quantities of air and retains any suspended particles, collected large volumes of fog droplets from June through August 2011. In the 25 samples they analyzed, concentrations of all forms of mercury averaged 10.7 nanograms per liter, and levels of monomethyl mercury averaged 3.4 nanograms per liter, they reported last month in Geophysical Research Letters. The latter concentration, the first such measurement ever reported from fog water, “is about five times the highest concentration ever seen in rainwater,” Weiss-Penzias notes. Using data from previous studies, including those of other teams, the researchers estimated that between 61% and 99% of the monomethyl mercury deposited in coastal ecosystems around Monterey Bay over the course of a year comes from fog.

The new findings don’t offer any ideas for minimizing mercury exposures in coastal environments, Weiss-Penzias says, but they do allow scientists to better understand how mercury may be making its way into those ecosystems. Future experiments, he says, will include measuring mercury levels in creatures at the base of the food chain, such as insects that may be drinking mercury-tainted fog droplets that have condensed on coastal plants.

doi: http://dx.doi.org/10.1029/2011GL050324

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Ash Shuqayq (Saudi Red Sea coast) is approximately 28 km long and characterised by narrow rocky headlands with intermittent pocket beaches. Fifty-two sediment samples from six different environments (beach, dune, sabkha, tidal/lagoon, offshore and wadi) were analysed. Testing showed that beach and dune sands are mainly medium to fine grained, with some very coarse sand (MZ = − 0.59ø). Both beach and dune sands are moderately well to moderately sorted, although some are poorly sorted due to an influx of wadi sediments. Sediment source together with littoral reworking contributed to grain size variation. Carbonate content varied between 1.5% and 23%, whilst the organic content varied between 1.1% and 13%. Spatial analysis showed increasing southward carbonate and organic content, with both correlated (r = 0.57). Sabkha sediments had significantly higher carbonate percentages (t = 2.898; df = 18; p < 0.01) and results suggested origins are similar for both UAE Arabian Sea and Saudi Arabian Red Sea coasts. X-ray diffractions show beach and dune sediments are mainly composed of detrital quartz and plagioclase feldspar with uncommon amounts of chlorites. Analysis of sediment characteristics, composition and shoreline distribution alongside coastal processes, indicate that high chlorite levels are probably caused by desalination processes. Due to human and ecosystem health consequences and the likely increased demand for desalination plants, similar analyses should be undertaken elsewhere, e.g. the Mediterranean.

http://dx.doi.org/10.1016/j.scitotenv.2012.01.050

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