Remobilization of trace elements by forest fire in Patagonia,Chile

Temporal changes in the amounts of trace elements (As, Co, Cu, Mn, Ni, Pb, and Zn) and their correlations with temporal changes in charcoal abundance in age-dated sediments collected from Lake Thompson in Patagonia, Chile, attest to the substantial pyrogenic remobilization of contaminants that occurred in Patagonia during the mid-1900s. This remobilization was concurrent with the extensive slash and burn period in the region during that period. The changes in concentrations of Co, Cu, and Ni in relation to charcoal abundance in the lacustrine sediments over time were small compared to those of As, Mn, Pb, and Zn. However, the relatively low enrichment factors of all those trace elements, normalized to Fe, indicate that they were predominantly derived from local, natural sources impacted by fires rather than industrial sources. The primarily local source of Pb in the sediments was corroborated by the temporal consistency of its isotopic ratios (²⁰⁶Pb/²⁰⁷Pb:²⁰⁸Pb/²⁰⁶Pb), which were similar to previously reported values for natural lead in Central and Southern Chile. However, the pyrogenic remobilization of both natural and industrial trace elements by forest fires in Chile and elsewhere is expected to rise as a consequence of climate change, which is projected to increase both the frequency and intensity of forest fires on a global scale.     

Assessment of compost quality for its environmentally safe use by means of an ecotoxicological test on a soil organism

A research project was carried out to evaluate toxicological effects of compost addition to agricultural soil using the earthworm Eisenia foetida (Annellida) as a representative organism of the soil fauna. Moreover, the correlation between compost biochemical stabilization and toxicity at different phases of the composting process was assessed. Samples were collected from three composting plants at three different maturation levels (beginning of the composting process, intermediate compost after bio-oxidation, and mature refined compost). Two tests were performed: a standard chronic solid-phase test and an acute solid-phase test (developed originally by the authors). In the first test, the measured end-points were mortality, growth and reproduction; while in the second test earthworms’ behavior was evaluated. The chosen compost concentrations in soil ranged from 2.5 to 100 %, with the aim of obtaining the toxicological parameters (LC50) and to mimic real agricultural dosages for the lower concentrations. Results indicated an increase in compost toxicity with greater compost concentrations; in particular, agricultural compost dosage below 10 % showed no toxicity. Moreover, toxicity did not decrease during composting; intermediate compost showed the highest LC50 values. As a consequence, no correlation was ascertained between the results of ecotoxicological analysis and waste biochemical stability parameters during the composting process.     

Optimization of Microwave-Assisted and Conventional Heating Comparative Synthesis of Poly(lactic acid) by Direct Melt Polycondensation from Agroindustrial Banana (Musa AAA Cavendish) and Pineapple (Ananas comosus) Fermented Wastes

In Costa Rica, a lot of pineapple (Ananas comosus) and banana (Musa AAA) agroindustrial residues are generated each year. These residues can be used to obtain l-lactic acid by fermentation, ultrafiltration and electrodialysis. Poly(l-lactic acid) (PLLA) is a biodegradable and renewable polyester with many industrial and biomedical applications. There is a growing interest to improve the energetic efficiency of the synthesis of PLLA, because the main issue to produce this polymer is the high productive cost compared with petrochemical traditional commodities. In this research, the synthesis of PLLA through two different techniques was compared: microwave-assisted and conventional heating. On microwave synthesis the best results were obtained using lower temperatures and lower reaction times than the conventional heated synthesis. The reaction time was reduced from 15 h by conventional heating to 4.5 h using microwave-assisted synthesis.     

Chemical and morphological characterization of aerosol particles at Mt. Krvavec, Slovenia, during the Eyjafjallajökull Icelandic volcanic eruption

Objective

In this work, continuous and size-segregated aerosol measurements at Mt. Krvavec, Slovenia, during the Eyjafjallajökull volcanic eruption were performed. Based on chemical and morphological characteristics of size-segregated particles, the presence of the volcanic aerosols after long-range transport to Slovenia was to be confirmed.

Results and conclusions

Continuous measurements with the aethalometer and SMPS indicated the suspected volcanic ash plume passing over the sampling site. The aerosols collected by discrete sampling showed a chemical signature similar to the known elemental signature of the Icelandic volcanic ash. Coarse particles showed a composition typical for silicates rich in metals; in many cases also S was present. Morphological analysis showed particles with features indicative of an explosive volcanic eruption, e.g., pumice and pumice shards, glass shards, minerals, evidence of steam condensation, etc. The high sulfate concentration associated with the fine particles resulted in sulfate crystallization within the cascade impactor leading to the formation of large structures resembling a “fern”. Mass size distributions for Fe, Ti, Mn, Ca, Na, and Mg showed one primary peak (for Fe, Mn, and Ti at 2.8 μm; for Ca, Na, and Mg at ca. 4 μm), which supports the fact that most of the particles in the coarse sizes were silicates rich in metals. The size distribution of the water-soluble SO ₄ ^2? showed a maximum peak at 0.75 μm, which also confirms the high sulfate concentration in the fine particles. Chemical and morphological characterization of aerosols collected at Mt. Krvavec indeed confirmed that volcanic ash plume passed over Slovenia.     

Ecotoxicological effects of sediments from Mar Piccolo,South Italy: toxicity testing with organisms from different trophic levels

The Mar Piccolo of Taranto (Ionian Sea, Southern Italy) is a semi-enclosed and strongly polluted basin. For decades, it has been subjected to different anthropogenic impacts. These stressors caused severe sediments contamination with high concentration of different pollutants (PAHs, PCB, heavy metals). In order to assess the current status of sediments contamination, an ecotoxicological investigation combined with chemical analysis (heavy metals, PAH, and PCB) has been performed. In order to derive ecologically relevant conclusions, a multiorganisms and multiend-points approach has been applied, exposing organisms from different trophic levels to elutriate and whole sediment. The battery of bioassays consists of a microalgal growth inhibition test (Dunaliella tertiolecta), acute and sublethal assays (end-points: mortality, immobilization and swimming speed alteration) on crustaceans larvae and juveniles, and rotifers (Amphibalanus amphitrite, Artemia salina, Corophium insidiosum and Brachionus plicatilis), and embryotoxicity test on echinoderms (Paracentrotus lividus). Considering the high levels of sediment contamination highlighted from chemical analysis, an unexpected very low toxic effect was observed, even considering the sublethal end-point (larval swimming speed alteration). The results of this study suggest a very complex contaminants dynamic in the Mar Piccolo sediments that, despite a strong level of contamination, seems to not affect in a proportional manner the biological compartment.     

Evaluation of genotoxicity and coumarin production in conventional and organic cultivation systems of Mikania glomerata Spreng

Abstract

Mikania glomerata Sprengel, popularly known as “guaco,” is used in Brazilian folk medicine for several inflammatory and allergic conditions. Besides, the popular use “guaco” is indicated by the Brazilian Ministry of Health as a safe and effective herbal medicine. The biological activity of M. glomerata extracts is due to the presence of the coumarins, a large family of phenolic substances found in plants and is made of fused benzene and α-pyrone rings. Considering that there are few data on the biological effects of the extracts of M. glomerata, mainly in genetic level, this work aims to evaluate, in vitro, the genotoxicity and coumarin production in M. glomerata in conventional and organic growing. The data showed that the organic culture system showed double the concentration of coumarin being significantly more productive than the conventional system. Besides, the results of comet assay suggest that extracts of M. glomerata cultivated in a conventional system was genotoxic, increased DNA damage levels while the organic extracts seem to have antigenotoxic effect possibly due to the concentration of coumarins. Additional biochemical investigations are necessary to elucidate the mechanisms of action of M. glomerata extracts, which were found to have a role in protection against DNA damage.     

BIOAMBIENT.ES study protocol: rationale and design of a cross-sectional human biomonitoring survey in Spain

Human biomonitoring (HBM), defined as the measurement of concentrations of chemicals or of their metabolites in human biological matrices, is considered the method of choice for determining internal exposures in individuals. HBM is part of environmental exposure surveillance systems in several countries. In 2007, the Ministry of Agriculture, Food and Environment promoted BIOAMBIENT.ES project, a national-level HBM study on environmental pollutants carried out in Spain to estimate levels of heavy metals, persistent organic pollutants, and other substances on the Spanish active workforce. BIOAMBIENT.ES is a nationwide cross-sectional study, with a stratified cluster sampling designed to cover all geographical areas, sex and occupational sectors, and aimed to obtain a representative sample of the Spanish workforce. Participants were recruited among people residing in Spain for 5 years or more, which underwent their annual occupational medical check-up in the health facilities of the Societies for Prevention of IBERMUTUAMUR, MUTUALIA, MC-PREVENCIÓN, MUGATRA, UNIMAT PREVENCIÓN, and PREVIMAC (March 2009–July 2010). A total of 1,892 subjects fulfilled the criteria for inclusion, donated biological samples (1,880 blood, 1,770 urine, and 577 hair) and completed a short self-administrated epidemiological questionnaire on environmental and lifestyle-related exposures. Additionally, clinical information from participant’s health exams was obtained. This project will provide a first overview of the body burden of selected pollutants in a representative sample of the Spanish-occupied population. This information will be useful to establish reference values of the studied population and, eventually, to evaluate temporal trends and the effectiveness of environmental and health policies.     

In vitro gossypol induced spermatozoa motility alterations in rabbits

The objectives of the present study were to: (i) examine the in vitro dose response of rabbit spermatozoa motility to the antifertility agent gossypol (GOS) and (ii) determine whether filtered (FIL) and unfiltered (UNFIL) GOS differ in their magnitude of effect. Rabbit semen belonging to adult males (n = 5; 12–14 months) were cultured with UNFIL GOS and FIL GOS (5% solution) and subsequently diluted (1:1–7) for analysis using a Computer Assisted Semen Analyzer (CASA) system in 5 time periods (0, 60, 120, 180 and 360 minutes). At Time 0, no significant change in rabbit spermatozoa motility (MOT) and progressive motility (PROG) with GOS FIL was noted, while increases were observed with GOS UNFIL. At Time 60, weak changes were noted for MOT and PROG. After 120 minutes of culture with both GOS FIL and GOS UNFIL, MOT and PROG decreased significantly in some experimental groups. However, no differences were recorded for both the parameters at Times 180 and 360, with the exception of PROG in the GOS UNFIL category (groups A, B, E, F and G), where a significant decrease was noticed. Detailed evaluation of the distance and velocity parameters revealed reduction in all these studied markers after 60 and 120 minutes of in vitro culture with both GOS FIL and GOS UNFIL, indirectly confirming the PROG decrease. Straightness (STR), linearity (LIN), wobble (WOB), amplitude of lateral head displacement (ALH) and beat cross frequency (BCF) mostly remained unaltered at all time periods for GOS FIL, where as some minor alterations were noticed in GOS UNFIL category for STR, LIN, WOB, ALH and BCF parameters at Time 0, 60 and 120. The present study confirms the dose and time dependent alterations of rabbit spermatozoa motility parameters by GOS. The GOS dynamics in our experiment shows that rabbit spermatozoa as a biological material can indicate a GOS inhibition of motility. Obtained data for the first time indicates a higher immobilizing potential of unfiltered GOS in comparison to filtered GOS in its inhibitory action of spermatozoa motility parameters in rabbits.     

Solid-phase extraction for multi-residue analysis of pesticides in honey

A fast and simple multi-residue method for the analysis of 15 organophosphorus (OP), 17 organochlorine (OC), 8 pyrethroids (PYR), 12 N-methyl-carbamate (NMC) pesticide residues and bromopropylate in honey is presented. Ready–to–use EXtrelut®NT 20 column, eluted with dichloromethane, was used to extract the pesticide residues from the aqueous-acetone honey sample, obtaining a clean extract directly analyzable. Determination was carried out by gas chromatography (GC) coupled with flame photometric detector (FPD) for OP compounds and by GC coupled with mass spectrometry detector (MSD) for OC and PYR pesticides and bromopropylate. The NMC pesticides were analysed by liquid chromatography-double derivatization coupled with spectrofluorimetric detector (LC/DD/Fl). This method allows the determination of the 53 pesticide residues at low concentrations (0.0005–0.074 mg/kg) and can be used to assess the compliance with the Maximum Residues Levels (MRLs) set by the European Union. The performance of the method was evaluated and specificity, linearity, recovery, repeatability, reproducibility, limit of quantification (LOQ) and limit of detection (LOD) were determined. A good linearity (r²? 0.99) was found in the range 0.0005–0.074 mg/kg for the majority of the compounds studied. Most of the pesticides had recoveries in the range 70–103 % and values of relative standard deviation (RSD) < 20 for repeatability and reproducibility, showing good accuracy and precision of the method. Aldicarb partially degraded in aldicarb sulphoxide during the analytical procedure, giving anomalous values. The LOQ for all pesticides investigated was from 0.0005 to 0.025 mg/kg while the LOD ranged from 0.0002 to 0.008 mg/kg.