Effects of microplastics alone or with sorbed oil compounds from the water accommodated fraction of a North Sea crude oil on marine mussels (Mytilus galloprovincialis).

Microplastics (MPs) can adsorb persistent organic pollutants such as oil hydrocarbons and may facilitate their transfer to organisms (Trojan horse effect). The aim of this study was to examine the effects of a 21 day dietary exposure to polystyrene MPs of 4.5 µm at 1000 particles/mL, alone and with sorbed oil compounds from the water accommodated fraction (WAF) of a naphthenic North Sea crude oil at two dilutions (25 % and 100 %), on marine mussels. An additional group of mussels was exposed to 25 % WAF for comparison. PAHs were accumulated in mussels exposed to WAF but not in those exposed to MPs with sorbed oil compounds from WAF (MPs-WAF), partly due to the low concentration of PAHs in the studied crude oil. Exposure to MPs or to WAF alone altered the activity of enzymes involved in aerobic (isocitrate dehydrogenase) and biotransformation metabolism (glutathione S-transferase). Prevalence of oocyte atresia and volume density of basophilic cells were higher and absorption efficiency lower in mussels exposed to MPs and to WAF than in controls. After 21 days MPs caused DNA damage (Comet assay) in mussel hemocytes. In conclusion, a Trojan horse effect was not observed but both MPs and oil WAF caused an array of deleterious effects on marine mussels at different levels of biological organization.

Impact of Artemisia absinthium hydrolate extracts with nematicidal activity on non-target soil organisms of different trophic levels.

Natural pesticides are considered a good alternative to synthetic pesticides to reduce environmental impacts. However, biopesticides may have unknown effects on the environment, and can affect non-target organisms. In this study, the ecotoxicological effects of an aqueous extract (hydrolate) from Spanish populations of Artemisia absinthium (var. Candial) showing a promising biopesticide activity, were evaluated on non-target soil organisms from different trophic levels (natural microbial communities characterized through 16S rRNA gene sequencing, the earthworm Eisenia fetida and the plant Allium cepa). The hydrolate usually was considered as a by-product of the distillation to obtain essential oils. However, recently has been found to have nematicide properties. The hydrolate caused acute toxicity at values of LC50 of 3.87% v/v for A. cepa and 0.07 mL/g for E. fetida. All the concentrations except for the most diluted (1% v/v) reduced the bacterial physiological activity compared to controls (LC50 = 25.72% v/v after 24 h of exposure). The hydrolate also slightly altered the ability of the microbial community to degrade carbon substrates. These results indicate that the hydrolate from A. absinthium may affect the survival and metabolic abilities of key soil organisms.

Ecotoxicity of a new biopesticide produced by Lavandula luisieri on non-target soil organisms from different trophic levels.

Plant-based biopesticides have become an eco-friendly alternative to synthetic pesticides by reducing the undesired environmental impacts and side-effects on human health. However, their effects on the environment and especially on non-target organisms have been little studied. This study analyses the ecotoxicological effects of the extract of Lavandula luisieri on soil non-target organisms from different trophic levels: the earthworm Eisenia fetida, the plant Allium cepa and a natural-soil microbial community whose taxonomy was analysed through 16S rRNA gene sequencing. The extract tested is the hydrolate -product from a semi industrial steam distillation process- of a Spanish pre-domesticated variety of L. luisieri. This hydrolate has been recently shown to have bionematicide activity against the root-knot nematode Meloidogyne javanica. A previous study showed that the main components of the hydrolate are camphor and 2,3,4,4-Tetramethyl-5-methylidenecyclopent-2-en-1-one. Hydrolate caused acute toxicity (LC50 2.2% v/v) on A. cepa, while only a slight toxicity on E. fetida (LC50 > 0.4 mL/g). All the concentrations tested (from 1 to 100% v/v) caused a significant decrease in bacterial growth (LC50 9.8% v/v after 120 h of exposure). The physiological diversity of the community was also significantly altered, except in the case of the lowest concentration of hydrolate (1% v/v). The ability of soil microbial communities to use a variety of carbon sources increased for all substrates at the highest concentrations. These results show that both the plants and bacterial communities of the soil can be affected by the application of biopesticides based on these hydrolates, which highlights the need for a more detailed risk assessment during the development of plant-based products.

Ecotoxicity of a novel biopesticide from Artemisia absinthium on non-target aquatic organisms.

Biopesticides are increasingly being used to replace synthetic pesticides for pest control. This change raises concern for its environmental impacts, especially on non-target organisms. In this study, the ecotoxicological effects of a potential nematicide from Spanish populations of Artemisia absinthium (var. Candial) were evaluated on freshwater and aquatic non-target organisms. The study focused on the aqueous extract (hydrolate), the principal component of which ((-) -(Z) -2,6-dimethylocta-5,7-diene-2,3-diol) is responsible for its nematicidal effect. Until now, the hydrolate has been considered a byproduct of the process used to obtain essential oils, and there are no studies on its ecotoxicity from any plant with biopesticide properties. Our results indicated that A. absinthium hydrolate caused acute toxicity for non-target organisms at dilutions as low as 0.2%. The sensitivity of the organisms, from the most to the least sensitive, was: Daphnia magna (LC50 = 0,236%) > Vibrio fisheri (LC50 = 1,85%) > Chlamydomonas reinhardtii (LC50 = 16,49). Moreover, the A. absinthium organic extract was highly toxic to D. magna (LC50 = 0,093 mg/L). A. absinthium hydrolate toxicity was also tested on a natural river microbial community. Bacterial growth was not affected; the physiology of the community was only slightly modified, namely through an increased ability to degrade different substrates, mainly carbohydrates. This study provides for the first time an exhaustive assessment of the environmental exposure of a plant-derived biopesticide and shows that these products may cause a broad range of toxicity on non-target aquatic organisms.

Soda pulp and fuel gases synthesis from Hesperaloe funifera.

The main objective of this work is to evaluate the suitability of Hesperaloe funifera which is an alternative raw material, for pulping with soda-anthraquinone to produce pulp and paper. It was studied the influence of operational variables (temperature (155-185 degrees C), cooking time (20-60 min) and soda concentration (5-15%), with a constant addition of 1% of anthraquinone and a liquid/solid ratio of 8, in soda-anthraquinone cooking of H. funifera on pulps and paper sheets properties obtained. Finally, the cooking liquors were acidified to separate solid fractions that were subjected to pyrolysis and gasification in order to obtain synthesis and fuel gases. H. funifera contains little lignin and abundant alpha-cellulose; this, together with the morphological characteristics of its fibers, makes it a potentially highly useful papermaking raw material.

Contaminación por petróleo

El autor en su trabajo nos presenta el problema que producen los residuos resultantes de la explotación y uso del petróleo. La explotación de este energético al igual que sus desechos se incrementarán significativamente en las siguientes décadas, por lo tanto, ésta debe ser una época de cambio: de una economía de desperdicio a otra economía racional y de justicia social