Matrix effect on the performance of headspace solid phase microextraction method for the analysis of target volatile organic compounds (VOCs) in environmental samples

Solid phase microextraction (SPME) is a fast, cheap and solvent free methodology widely used for environmental analysis. A SPME methodology has been optimized for the analysis of VOCs in a range of matrices covering different soils of varying textures, organic matrices from manures and composts from different origins, and biochars. The performance of the technique was compared for the different matrices spiked with a multicomponent VOC mixture, selected to cover different VOC groups of environmental relevance (ketone, terpene, alcohol, aliphatic hydrocarbons and alkylbenzenes). VOC recovery was dependent on the nature itself of the VOC and the matrix characteristics. The SPME analysis of non-polar compounds, such as alkylbenzenes, terpenes and aliphatic hydrocarbons, was markedly affected by the type of matrix as a consequence of the competition for the adsorption sites in the SPME fiber. These non-polar compounds were strongly retained in the biochar surfaces limiting the use of SPME for this type of matrices. However, this adsorption capacity was not evident when biochar had undergone a weathering/aging process through composting. Polar compounds (alcohol and ketone) showed a similar behavior in all matrices, as a consequence of the hydrophilic characteristics, affected by water content in the matrix. SPME showed a good performance for soils and organic matrices especially for non-polar compounds, achieving a limit of detection (LD) and limit of quantification (LQ) of 0.02 and 0.03 ng g⁻¹ for non-polar compounds and poor extraction for more hydrophilic and polar compounds (LD and LQ higher 310 and 490 ng g⁻¹). The characteristics of the matrix, especially pH and organic matter, had a marked impact on SPME, due to the competition of the analytes for active sites in the fiber, but VOC biodegradation should not be discarded in matrices with active microbial biomass.     

Organochlorine compounds in bovine milk from the state of Mato Grosso do Sul – Brazil

Organochlorines are highly hydrophobic, synthetic organic pollutants that accumulate in the environment and in food webs. The primary route of human exposure to organochlorines is through food-mainly fat-rich food of animal origin such as meat, fish, and dairy products. Here we determined the presence and concentration of organochlorine residues in pasteurized milk from Mato Grosso do Sul, Brazil, to monitor consumer exposure to these contaminants. Organochlorine pesticides in milk samples were analyzed using solid phase extraction in octadecyl silica-prepacked columns and identified by gas chromatography using an electron capture detector. Of the 100 composite samples analyzed, more than 90% contained residues of organochlorine pesticides: aldrin was present in 44% of the samples, followed by ∑DDT (36%), mirex (34%), endosulfan (32%), chlordane (17%), dicofol (14%), heptachlor (11%) and dieldrin (11%). Compared to the values established by law, the concentration of the compounds in some samples was above the reference values. Given the importance that milk and its products have in the human diet, it is essential to know whether the levels of pesticide residues are kept well below the recommended levels to minimize the risk to human health.     

Biochemical biomarkers in Nile tilapia (Oreochromis niloticus) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends

Fossil fuels such as diesel are being gradually replaced by biodiesel, a renewable energy source, cheaper and less polluting. However, little is known about the toxic effects of this new energy source on aquatic organisms. Thus, we evaluated biochemical biomarkers related to oxidative stress in Nile tilapia (Oreochromis niloticus) after two and seven exposure days to diesel and pure biodiesel (B100) and blends B5 and B20 at concentrations of 0.01 and 0.1 mL L⁻¹. The hepatic ethoxyresorufin-O-deethylase activity was highly induced in all groups, except for those animals exposed to B100. There was an increase in lipid peroxidation in liver and gills in the group exposed to the higher concentration of B5. All treatments caused a significant increase in the levels of 1-hydroxypyrene excreted in the bile after 2 and 7 d, except for those fish exposed to B100. The hepatic glutathione-S-transferase increased after 7 d in animals exposed to the higher concentration of diesel and in the gill of fish exposed to the higher concentration of pure diesel and B5, but decreased for the two tested concentrations of B100. Superoxide dismutase, catalase and glutathione peroxidase also presented significant changes according to the treatments for all groups, including B100. Biodiesel B20 in the conditions tested had fewer adverse effects than diesel and B5 for the Nile tilapia, and can be suggested as a less harmful fuel in substitution to diesel. However, even B100 could activate biochemical responses in fish, at the experimental conditions tested, indicating that this fuel can also represent a risk to the aquatic biota.     

Implications of geographic variability on Comparative Toxicity Potentials of Cu, Ni and Zn in freshwaters of Canadian ecoregions

Current methods of estimating potential environmental impacts of metals in hazard and Life Cycle Impact Assessment (LCIA) do not consider differences in chemistry and landscape properties between geographic sites. Here, we developed and applied a model for regional aquatic impact characterization of metals using an updated method for estimating environmental fate factor (FF), bioavailability factor (BF) and aquatic ecotoxicity factor (EF). We applied the model to analyze differences in Comparative Toxicity Potentials (CTPs) of Cu, Ni and Zn for 24 Canadian ecoregions. The combined impacts of regional variability in ambient chemistry (in particular DOC, pH and hardness) and landscape properties (water residence time) can change the CTPs of these metals for freshwater by up to three orders of magnitude and change the relative ranking of metal hazard between ecoregions. Variation among Canadian freshwater chemistries and landscape characteristics influence the FFs within two orders of magnitude, BFs within two orders of magnitude for Ni and Zn and four orders of magnitude for Cu, and EFs within one order of magnitude. Sensitivity of metal FFs to environmental parameters alone spans three orders of magnitude when a constant water chemistry was used for all ecoregions. These results indicate that application of regionalised metal CTPs can have a significant influence in the analysis of ecotoxicological impacts in the life cycle assessment of products and processes.     

Occurrence and distribution of pharmaceuticals in surface water, suspended solids and sediments of the Ebro river basin, Spain

The occurrence of 43 pharmaceuticals belonging to predominant therapeutic classes and their distribution in surface water, suspended solids and sediments has been investigated in the Ebro river basin in the Northeast of Spain. WWTP effluents were found to be a main source of contamination and the spatial distribution was affected by the river flow at the sampling point and corresponding dilution factor, resulting in higher concentrations and higher loads in small tributary rivers than in the Ebro river. The study showed that some compounds are preferentially found bound to suspended solids and not detected in river water. Generally, compounds with basic characteristics (pKa > 7) showed higher tendency to bind to suspended solids. The sediment samples generally presented lower concentrations than suspended solids.     

Variability in environmental impacts of Brazilian soybean according to crop production and transport scenarios

Soybean production and its supply chain are highly dependent on inputs such as land, fertilizer, fuel, machines, pesticides and electricity. The expansion of this crop in Brazil in recent decades has generated concerns about its environmental impacts. To assess these impacts, two representative chains supplying soybeans to Europe were identified: Center West (CW) and Southern (SO) Brazil. Each supply chain was analyzed using Life Cycle Assessment methodology. We considered different levels of use of chemical and organic fertilizers, pesticides and machinery, different distances for transportation of inputs and different yield levels. Because transportation contributed strongly to environmental impacts, a detailed study was performed to identify the routes used to transport soybeans to seaports. Additionally, we considered different levels of land occupation and land transformation to represent the impact of deforestation in the CW region. Environmental impacts were calculated for 1000 kg of soybean up to and including the delivery to Europe at the seaport in Rotterdam, at 13% humidity. Overall results showed that the impacts are greater for CW than for SO for all impact categories studied, including acidification (7.7 and 5.3 kg SO₂ eq., respectively), climate change (959 and 510 kg CO₂ eq.), cumulative energy demand (12,634 and 6,999 MJ) and terrestrial ecotoxicity (4.9 and 3.1 kg 1,4-DCB eq.), except eutrophication and land occupation. The same trend was observed for the crop-production stage. Efforts to reduce chemical fertilizers and diesel consumption can reduce CO₂ emissions. Although deforestation for crop production has decreased in recent years, the contribution of deforestation to climate change and cumulative energy demand remains significant. In the CW scenario deforestation contributed 29% to climate change and 20% to cumulative energy demand. Results also showed that although there are different transportation options in Brazil, the current predominance of road transport causes severe environmental impacts. In CW, road transport contributed 19% to climate change and 24% to cumulative energy demand, while in SO it contributed 12% and 15% to these impacts, respectively. Improvements in the logistics of transportation, giving priority to rail and river transports over road transport, can contribute significantly to reducing greenhouse gas emissions and decreasing energy use. Future studies involving Brazilian soybeans should take into account the region of origin as different levels of environmental impact are predicted.     

Risk on the ramble: The international transfer of risk and vulnerability

In this paper the purpose is to discuss a concept of technology that can explain how the transfer of technology implies the risk of new failures, misuse, accidents and unhealthy workplaces. Production technologies are often transformed through a steady stream of incremental changes appropriate to their social context, and the technology will therefore gradually acquire some contextually dependent preconditions for use. These preconditions will most probably be revealed when a technology is transferred from one context to another. Thus, a technology transfer project may trigger a long process of re-innovations just to make the technology fully operational in its new context. In a transfer process, technological risks may arise due to incomplete transfer of mastering capacity; mismatch between transferred technology and the environment; transfer of latent conditions for failure; and the transformation of latent conditions or known risks when the technology is installed in a new environment. Longitudinal data from the Norwegian petroleum industry indicates that the first phases in a transfer process will create high technological risks. It will take many years before the transferred technologies are adapted to the new context and the risk level has been normalised.     

Implication of nitric oxide in the heat-stress-induced cell death of the symbiotic alga <Emphasis Type="Italic">Symbiodinium microadriaticum</Emphasis>

One of the major consequences of global warming is a rise in sea surface temperature which may affect the survival of marine organisms including phytoplankton. Here, we provide experimental evidence for heat-induced cell death in a symbiotic microalga. Shifting Symbiodinium microadriaticum from 27 to 32°C resulted in an increase in mortality, an increase in caspase 3-like activity, and an increase in nitric oxide (NO) production. The caspase-like activity was strongly correlated with the production of NO in thermally challenged microalgae. For this experiment, the application of Ac-DEVD-CHO, a mammalian caspase 3-specific inhibitor, partly prevented (by 65%) the increase in caspase-like activity. To verify the relationship between NO and the caspase-like activity, S. microadriaticum were subsequently incubated with 1.0 mM of the following chemical NO donors: sodium nitroprusside (SNP), S-nitrosoglutathione (GSNO), S-nitroso-N-acetylpenicillamine (SNAP) and 3,3bis(Aminoethyl)-1-hydroxy-2-oxo-1-triazene (NOC-18). The supplementation of both SNP and NOC-18 caused a significant increase in caspase-like activity compared to the control treatment. Pre-treatment of the microalgae with the inhibitor Ac-DEVD-CHO before the supplementation of the different NO donors completely prevented the increase in caspase-like activity. These results suggest that NO could play a role in the induction of cell death in heat-stressed S. microadriaticum by mediating an increase in caspase-like activity.     

Garnering support for Pigouvian taxation with tax return: a lab experiment

Environmental Economics and Policy Studies - To test if tax return can effectively and efficiently increase the acceptance of externality taxation, a laboratory experiment with a negative...