Genotoxic assessment on river water using different biological systems

This paper reports genotoxicity and toxicity data in water samples collected in Sinos River, an important water course in the hydrographic region of Guaíba Lake, Rio Grande do Sul State, south of Brazil. This river is exposed to intense anthropic influence by numerous shoes, leather, petrochemical, and metallurgy industries. Water samples were collected at two moments (winter 2006 and spring 2006) at five sites of Sinos River and evaluated using in vitro V79 Chinese hamster lung fibroblasts (cytotoxicity, comet assay and micronucleus test) and Allium cepa test (toxicity and micronucleus test). Comet and micronucleus tests revealed that water samples collected exerted cytotoxic, toxic, genotoxic and mutagenic effects. The results showed the toxic action of organic and inorganic agents found in the water samples in all sites of Sinos River, for both data collections. The main causes behind pollution were the domestic and industrial toxic discharges. The V79 and A. cepa tests were proved efficient to detect toxicity and genotoxicity caused by complex mixtures. This study also showed the need for constant monitoring in sites with strong environmental degradation caused by industrial discharges and urban sewages.     

Adsorption behavior of 17α-ethynylestradiol onto soils followed by fluorescence spectral deconvolution

In this study, a simple and rapid procedure for monitoring adsorption of 17α-ethynylestradiol (EE2) onto soil samples was developed. The used method is based on a multiwavelength fluorescence spectral deconvolution (FSD) where the emission fluorescence spectrum of a sample is considered as a linear combination of emission spectra, named reference spectra. The combination of the reference spectra allows the restitution of the shape of the emission spectrum of any unknown sample. This approach was applied to follow EE2 adsorption onto four soil samples and is an easy and low cost alternative.Adsorption experimental data showed a good fit with the Hill equation, mathematically equivalent to the Langmuir-Freundlich model assuming that the adsorption is a cooperative process influenced by adsorbate-adsorbate interactions. Molecular modelling studies clearly support the “co-operative adsorption” model, showing that after the adsorption of the first layer of EE2 molecules onto the soil, at least one more layer of EE2 is adsorbed, due to interactions established with the first adsorbed layer. Notwithstanding, packing a third row would imply interactions between two EE2 molecules that differ from the ones verified in the lowest energy structure, which also explains the plateau achieved in the adsorption curve.     

LED irradiated photo-Fenton for the removal of estrogenic activity and endocrine disruptors from wastewater treatment plant effluent

Environmental Science and Pollution Research - The goal of this work was to evaluate the performance of the LED irradiated photo-Fenton process on the removal of (i) estrogenic activity and (ii)...     

Encapsulation of Nerol Oil in Polycaprolactone Polymer and Stability Evaluation

Journal of Polymers and the Environment - The objective of this study was to obtain and characterize Nerol essential oil encapsulated in PCL. The miniemulsion and solvent evaporation method was...     

The role of environmental and fisheries multi-controls in white seabream (Diplodus sargus) artisanal fisheries in Portuguese coast

Evaluating the effects of fishing and environmental factors on fish populations are fundamental tenets of fisheries science. In this study, we assess associations between environmental variables (sea surface temperature; North Atlantic Oscillation index; upwelling; wind magnitude; westerly winds; northerly winds; river discharge) and fishing variables (fishing effort) in Diplodus sagus catch rates accounting for regional analyses (northwest coast; southwest coast and Algarve—Algarve south coast). Different time series models for data fitting (multi-model approach) were used. The models were lagged, according to species fishing recruitment age based on the hypothesis that fisheries catches depend on larvae recruitment and survivorship. D. sargus catch rates across areas were unrelated to fishing effort but correlated to environmental variables, with seasonal events explaining much of the variability in trends. On the northwestern coast, the catch rates were mainly set by sea surface temperature (SST) and wind magnitude; however, southwestern coast catch rates were set by NAO winter. On the south coast, only one statistical model (SST, upwelling and westerly winds) associated spring conditions with D. sargus catch rates. The multi-model approach revealed autumn, winter and spring seasonal effects to be related with northwest, southwest and Algarve coastal catch rates, respectively, indicating a possible coastal longitudinal gradient related with given periods of spawning and larval availability. The metadata analysis yielded different results from the regional analyses. In summary, marine resource management should take regional environment characteristics and variability into account when determining sustainable catch rates in given areas for species with high habitat site fidelity.     

Reassessing the role of the honeybee (Apis mellifera) Dufour's gland in egg marking

Dufour's gland secretion may allow worker honeybees to discriminate between queen-laid and worker-laid eggs. To investigate this, we combined the chemical analysis of individually treated eggs with an egg removal bioassay. We partitioned queen Dufour's gland into hydrocarbon and ester fractions. The bioassay showed that worker-laid eggs treated with either whole gland extract, ester fraction or synthetic gland esters were removed more slowly than untreated worker-laid eggs. However, the effect only lasted up to 20 h. Worker-laid eggs treated with the hydrocarbon fraction were removed at the same rate as untreated eggs. The amount of ester which reduced the egg removal rate was far higher than that naturally found on queen-laid or worker-laid eggs, and at natural ester levels no effect was found. Our results indicate that esters or hydrocarbons probably do not function as the signal by which eggs can be discriminated.