Toxicity assessment of 2,4-D and MCPA herbicides in primary culture of fish hepatic cells

In this study, we used primary cultures of fish hepatic cells as a tool for evaluating the effects of environmental contamination. Primary hepatic cell cultures derived from the subtropical fish Metynnis roosevelti were exposed to different concentrations (0.275, 2.75 and 27.5 μg L^?1) of the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-methylphenoxyacetic acid (MCPA). Cellular respiratory activity was evaluated by polarography using three substrates: 0.5 M glucose, 0.5 M succinate and 0.5 M α-ketoglutarate. Significant changes were observed in cellular oxygen consumption with 0.5 M α-ketoglutarate. Even at low concentrations, 2,4-D and MCPA were potent uncouplers of oxidative phosphorylation. Primary cultures of M. roosevelti liver cells may provide a useful tool for the evaluation of environmental contaminant effects. A review of regulations regarding permitted concentrations of these herbicides is needed.     

Solving mercury (Hg) speciation in soil samples by synchrotron X-ray microspectroscopic techniques

Direct mercury (Hg) speciation was assessed for soil samples with a Hg concentration ranging from 7 up to 240 mg kg⁻¹. Hg chemical forms were identified and quantified by sequential extractions and bulk- and micro-analytical techniques exploiting synchrotron generated X-rays. In particular, microspectroscopic techniques such as μ-XRF, μ-XRD and μ-XANES were necessary to solve bulk Hg speciation, in both soil fractions <2 mm and <2 μm. The main Hg-species found in the soil samples were metacinnabar (β-HgS), cinnabar (α-HgS), corderoite (Hg₃S₂Cl₂), and an amorphous phase containing Hg bound to chlorine and sulfur. The amount of metacinnabar and amorphous phases increased in the fraction <2 μm. No interaction among Hg-species and soil components was observed. All the observed Hg-species originated from the slow weathering of an inert Hg-containing waste material (K106, U.S. EPA) dumped in the area several years ago, which is changing into a relatively more dangerous source of pollution.     

Meteorological and pedological influence on the PCBs distribution in mountain soils

Polychlorinated biphenyls (PCBs) are a threat to environmental and human health due to their persistence and toxicological effects. In this paper, we analyse some meteorological and organic-matter-related effects on their distribution in the soils of an Alpine environment that is not subject to direct contamination. We collected samples and measured the contamination of 12 selected congeners from three soil layers (O, A1 and A2) and from North-, plain- and South-facing slopes on six different dates spanning the entire snowless portion of the year. We recorded the hourly air and soil temperatures, humidity and rainfall in the study period. We found evidence that PCBs contamination in soils varies significantly, depending on sampling date, layer and aspect. The observed seasonal trend shows an early summer peak and a rapid decrease during June. The layer effect demonstrates higher dry-weight-based concentrations in the O layer, whereas the differences are much smaller for SOM-based concentrations. Different factors caused significantly higher concentrations in northern soils, with a N/S enrichment factor ranging from 1.8 to 1.5 during the season. The southern site has significantly more rapid early-summer re-volatilisation kinetics (half-time of 16 d for South, 25 d for North).     

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 EXtrelutNT 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 (r(2)≥ 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.     

Determination of acidic herbicides in cereals by QuEChERS extraction and LC/MS/MS

A simple and rapid method has been studied for the determination of acidic herbicides (2,4-D, Dichlorprop, Dichlorprop-p, Fluazifop, Fluroxypyr, MCPA, Mecoprop and Mecoprop-p) on cereals (rye). The method involves an alkaline hydrolysis with sodium hydroxide in order to release covalently bound compounds, prior to QuEChERS extraction, followed by neutralization and analysis via liquid chromatography-double mass spectrometry LC/MS/MS. The performance of the method either with or without alkaline hydrolysis was studied in terms of recovery rates and limit of quantification (LOQ). In either case, recoveries were determined at four spiking levels (0.02 mg/kg, 0.05 mg/kg, 0.1 mg/kg and 0.5 mg/kg) with 5 replicates for each level. Mean recoveries ranged from 90 to 120 %, whereas relative standard deviations (RSD %) proved to be less than 20 %. Quantitative analysis was carried out by the internal standard (Nicarbazin) and the LC/MS/MS analysis was performed in electrospray ionisation (ESI) negative mode using a Zorbax XCB Eclipse column. The developed method was applied to the analysis of several cereals commercially available like as rye flour, oat meal, oat flakes and dehusked oat. Residue levels were found below the limit of quantification (LOQ) of the method. The method has been tested in EU Proficiency Tests for cereals with good results.     

Right versus left: How does political ideology affect the workplace?

Underscored by perceived moral truths and at times punctuated by hypocrisy, political ideology is a deeply held conviction for many individuals, affecting their behavior. In an organizational setting, conflicting political ideologies may lead to a number of undesirable outcomes. This Incubator calls for further study into this important individual trait.     

Ecotoxicity Evaluation of the Biodegradable Polymers PLA,PBAT and its Blends Using <Emphasis Type="Italic">Allium cepa</Emphasis> as Test Organism

Biodegradable polymers are considered a feasible option to minimize the environment impacts of high disposal of solid waste. Nevertheless, environmental safety of these materials is a few explored issue. In this context, this study evaluated ecotoxicological effects in soil of the biodegradable materials poly(lactic acid)-PLA, poly(butylene adipate co-terephthalate)-PBAT and their blends compatibilized with a chain extender. The tool used for this analysis was the bioassay with Allium cepa as test organism. The studied materials were not phytotoxic, cytotoxic, genotoxic nor mutagenic for meristematic cells of A. cepa.     

Poly(lactic acid)/Cellulose Composites Obtained from Modified Cotton Fibers by Successive Acid Hydrolysis

This work is focused on the hydrolysis of cotton fibers from waste textiles to obtain micro and nanofibers to be used as reinforcements in polymer composites. To promote their compatibility with polymeric matrix, hydrolyzed cotton fibers were surface modified with various silane compounds. Thus, these fibers were mixed with commercial poly(lactic acid) (PLA) at 5% w/w loading by melt compounding. Acid treatments caused a decrease of the crystallinity index whereas the thermal stability was significantly improved, especially for cellulose fibers hydrolyzed in two steps. Morphological analysis revealed a reduction of the fibers diameter and a decrease of their length as a consequence of the hydrolysis. NMR analysis confirmed the silanization of the fibers by reaction with the silane agent. Tensile tests revealed that silanization treatments were able to increase the composite Young’s modulus and the stress at break with respect to the neat matrix, indicating that silanization improved the polymer/fiber compatibility interfacial adhesion. The overall results demonstrated that applying suitable surface modification strategies, waste cotton textiles can be effectively recycled as fillers in polymer based composites.     

Blood biomonitoring of metals in subjects living near abandoned mining and active industrial areas

A human blood biomonitoring campaign to detect the environmental exposure to metals (Cd, Cu, Cr, Mn, Pb and Zn) in 265 subjects was performed in the South-Western part of Sardinia (an Italian island) that is a particular area with a great history of coal and metal mining (Pb/Zn mainly) activities and large industrial structures (as metallurgy). Subjects living near the industrial plant area had geometric means (GM) of blood Cd (0.79 μg/l), Cu (971 μg/l), Mn (12.2 μg/l), and Pb (55.7 μg/l) significantly higher than controls (Cd, 0.47 μg/l; Cu, 900 μg/l; Mn 9.98 μg/l; Pb, 26.5 μg/l) and than people living nearby the past mining sites. Subjects living next to one dismissed mine were statistically higher in blood Cu (GM, 1,022 μg/l) and Pb (GM, 41.4 μg/l) concentrations than controls. No differences were observed in people living in the different mining sites, and this might be related to the decennial disclosure of mines and the adoption of environmental remediation programmes. Some interindividual variables influenced blood biomonitoring data, as smoke and age for Cd, gender for Cu, age, sex and alcohol for Pb, and age for Zn. Moreover, blood metal levels of the whole population were similar to reference values representative of the Sardinian population and acceptably safe according to currently available health guidelines.