Assessment of daily intake of organochlorine pesticides from milk in different regions of Poland

The common occurrence of organochlorine compounds in the environment, food and human tissues may constitute a serious threat to human health. The method of gas chromatography-mass spectroscopy was used to determine the content of pesticides in 15 samples of raw cow's milk from different regions of Poland. The results revealed high levels of p,p′-DDE, p,p′-DDT, heptachlor and aldrin. The studied milk contained lindane in average concentrations within the maximum limits. Although in 20% of all samples tested, the concentration of lindane exceeded permissible limits, while in 15% of samples the content of Σ DDT was too high. But the average daily consumption of milk containing organochlorine pesticides poses no direct threat to human health, because daily intake (DI) for all compounds were below the acceptable daily intake (ADI). Attention should be paid to the exposure of consumers to pesticide residues from other dairy foods.     

Validation of a multiclass multiresidue method and monitoring results for 210 pesticides in fruits and vegetables by gas chromatography-triple quadrupole mass spectrometry

A rapid, sensitive, accurate and reliable multiresidue method for the identification and quantification of 210 relevant pesticides in four representative fruit and vegetable commodities (tomato, potato, spring onion and orange) has been developed and validated by gas chromatography in tandem with triple quadrupole mass spectrometry. The method has been fully validated and applied to 292 samples from different countries. Prior to instrumental analysis, an extraction procedure based on a sample extraction of multiclass analytes, using the ethyl acetate method was employed. Mass spectrometric conditions were individually optimized for each compound in the selected reaction monitoring (SRM) mode to achieve maximum sensitivity. The pesticides were separated in less than 25 min. This was followed by an exhaustive control of the retention times. The Retention Time Locking Method was applied, working at a constant pressure throughout the analysis. System maintenance was reduced by using a purged capillary flow device that provided backflush capabilities by reversing column flow immediately after elution of the last compound of interest. Istotopically labelled internal standards were employed to improve the quality of the analytical results.     

Inferences About Radionuclide Mobility in Soils Based on the Solid/Liquid Partition Coefficients and Soil Properties

To assist transport modeling in assessments of the radiological impact of a geological repository for radioactive wastes, the mobility of various elements was studied in arable and wetland soils in the Forsmark region, Sweden. Pore water and total element contents were determined for five types of unconsolidated deposits (regolith), spanning a wide range of soil properties with respect to pH and organic matter content. Two soil depths were sampled to capture element mobility in regolith layers affected and unaffected by soil-forming processes. The solid/liquid partition coefficients (K _d values) for most elements varied significantly among regolith types. For most elements, the observed variations in K _d values could be explained by variations in soil properties. For many elements, mobility increased with decreasing soil pH. The results provide a significant addition of data on radionuclide retention in soils, taking account of soil properties and processes.     

Metal extractability patterns to evaluate (potentially) mobile fractions in periurban calcareous agricultural soils in the Mediterranean area—analytical and mineralogical approaches

A set of periurban calcareous agricultural Mediterranean soils was spiked with a mixture of Cd, Cu, Pb and Zn at two levels within the limit values proposed by current European legislation, incubated for up to 12 months, and subjected to various one-step extraction procedures to estimate mobile (neutral salts) and potentially mobile metal fractions (complexing and acidic extraction methods). The results obtained were used to study metal extractability patterns according to the soil characteristics. The analytical data were coupled with mineralogical investigations and speciation modelling using the Visual Minteq model. The formation of soluble metal-complexes in the complexing extracts (predicted by the Visual Minteq calculations) led to the highest extraction efficiency with complexing extractants. Metal extractability patterns were related to both content and composition of carbonate, organic matter, Fe oxide and clay fractions. Potentially mobile metal fractions were mainly affected by the finest soil fractions (recalcitrant organic matter, active lime and clay minerals). In the case of Pb, scarce correlations between extractable Pb and soil constituents were obtained which was attributed to high Pb retention due to the formation of 4PbCO₃·3PbO (corroborated by X-ray diffraction). In summary, the high metal proportion extracted with complexing agents highlighted the high but finite capacity to store potentially mobilizable metals and the possible vulnerability of these soils against environmental impact from metal accumulation.     

哥伦比亚的环境管理志愿举措:全国工业协会(ANDI)的参与

1990年代哥伦比亚采取了一批保护环境的举措.这些最初表现为涉及若干团体(尤其工业团体)的独立志愿运动,由全国工业协会(ANDI)、哥伦比亚塑料工业协会(Acoplastico)和哥伦比亚安全理事会(CCS)协调.这些团体支持国际环境管理发展,尤其<责任关怀计划>.自1994-1995年以来,在当局愈来愈积极--但仍有待完善--的参与支持下,签订了许多协调协议.尽管尚有不足之处,但哥伦比亚迄今为止所取得的进展依然不失为可持续发展道路上一个可以效仿的范例.     

Impact of biofumigation with solarization on degradation of pesticides and heavy metal accumulation

A greenhouse study was conducted to evaluate the effect of biofumigation (with sheep and chicken manure) combined with solarization on the dissipation of pesticides (pyrifenox, DDT and dieldrin), and on soil metals accumulation. The treatments consisted of a control, and soil disinfestations by biofumigation combined with solarization (B+S) for two, four, five, six consecutive years. B+S enhanced the dissipation of pyrifenox with regard to control treatment. Significant differences were not detected among plots disinfected with B+S for consecutive years. On the other hand, B+S had no effect on the dissipation of DDT and dieldrin, probably due to the resistance of these pesticides to microbial degradation and/or high temperatures. Biofumigation is considered to be an environmentally safe practice, since no accumulation of heavy metals such as Cd, Co, Cu, Cr, Pb, Ni, or Zn was observed after the subsequent application of organic matter through the treatments.     

Land-use changes and carbon sequestration through the twentieth century in a Mediterranean mountain ecosystem: Implications for land management

Ecosystems in the western Mediterranean basin have undergone intense changes in land use throughout the centuries, resulting in areas with severe alterations. Today, most these areas have become sensitive to human activity, prone to profound changes in land-use configuration and ecosystem services. A consensus exists amongst stakeholders that ecosystem services must be preserved but managerial strategies that help to preserve them while ensuring sustainability are often inadequate. To provide a basis for measuring implications of land-use change on carbon sequestration services, changes in land use and associated carbon sequestration potential throughout the 20th century in a rural area at the foothills of the Sierra Nevada range (SE Spain) were explored. We found that forest systems replaced dryland farming and pastures from the middle of the century onwards as a result of agricultural abandonment and afforestation programs. The area has always acted as a carbon sink with sequestration rates ranging from 28,961 t CO₂ year^?1 in 1921 to 60,635 t CO₂ year^?1 in 1995, mirroring changes in land use. Conversion from pastures to woodland, for example, accounted for an increase in carbon sequestration above 30,000 t CO₂ year^?1 by the end of the century. However, intensive deforestation would imply a decrease of approximately 66% of the bulk CO₂ fixed. In our study area, woodland conservation is essential to maintain the ecosystem services that underlie carbon sequestration. Our essay could inspire policymakers to better achieve goals of increasing carbon sequestration rates and sustainability within protected areas.     

Modelling annual pasture dynamics: Application to stomatal ozone deposition

Modelling ozone (O₃) deposition for impact risk assessment is still poorly developed for herbaceous vegetation, particularly for Mediterranean annual pastures. High inter-annual climatic variability in the Mediterranean area makes it difficult to develop models characterizing gas exchange behaviour and air pollutant absorption suitable for risk assessment. This paper presents a new model to estimate stomatal conductance (g_s) of Trifolium subterraneum, a characteristic species of dehesa pastures. The MEDPAS (MEDiterranean PAStures) model couples 3 modules estimating soil water content (SWC), vegetation growth and g_s. The g_s module is a reparameterized version of the stomatal component of the EMEP DO₃SE O₃ deposition model. The MEDPAS model was applied to two contrasting years representing typical dry and humid springs respectively and with different O₃ exposures. The MEDPAS model reproduced realistically the g_s seasonal and inter-annual variations observed in the field. SWC was identified as the major driver of differences across years. Despite the higher O₃ exposure in the dry year, meteorological conditions favoured 2.1 times higher g_s and 56 day longer growing season in the humid year compared to the dry year. This resulted in higher ozone fluxes absorbed by T. subterraneum in the humid year. High inter-family variability was found in gas exchange rates, therefore limiting the relevance of single species O₃ deposition flux modelling for dehesa pastures. Stomatal conductance dynamics at the canopy level need to be considered for more accurate O₃ flux modelling for present and future climate scenarios in the Mediterranean area.     

Year-round reproduction in a seasonal sea: biological cycle of the introduced ascidian Styela plicata in the Western Mediterranean

The widely introduced ascidian Styela plicata is very common in the Western Mediterranean, an area that can act as a source for secondary introductions due to its high shipping activity. In order to understand the potential of this species to colonize new habitats, its reproductive features were assessed in the Western Mediterranean by means of monthly monitoring of two populations (Vilanova i la Geltrú 41°12′53″N, 1°44′11″E; Blanes 41°40′29″N, 2°47′56″E) from January 2009 to December 2010. The reproductive activity of this species was assessed through gonad histology and a gonad index. Population size-structure was measured monthly in order to study recruitment dynamics. No clear seasonal pattern was observed, and mature gametes and recruits were present all year long. Spawning was potentially continuous, although it seemed punctuated with pulses of gamete release, particularly in spring. A prolonged reproductive period is likely to confer a competitive advantage on S. plicata in temperate seas, where most species reproduce seasonally, and may promote recurrent introductions as larvae are available for settlement on transport vectors over much of the year.     

Characterization of wood plastic composites made from landfill-derived plastic and sawdust: Volatile compounds and olfactometric analysis

Application of wood plastic composites (WPCs) obtained from recycled materials initially intended for landfill is usually limited by their composition, mainly focused on release of volatile organic compounds (VOCs) which could affect quality or human safety. The study of the VOCs released by a material is a requirement for new composite materials. Characterization and quantification of VOCs of several WPC produced with low density polyethylene (LDPE) and polyethylene/ethylene vinyl acetate (PE/EVA) films and sawdust were carried out, in each stage of production, by solid phase microextraction in headspace mode (HS-SPME) and gas chromatography–mass spectrometry (GC–MS). An odor profile was also obtained by HS-SPME and GC–MS coupled with olfactometry analysis. More than 140 compounds were observed in the raw materials and WPC samples. Some quantified compounds were considered WPC markers such as furfural, 2-methoxyphenol, N-methylphthalimide and 2,4-di-tert-butylphenol. Hexanoic acid, acetic acid, 2-methoxyphenol, acetylfuran, diacetyl, and aldehydes were the most important odorants. None of the VOCs were found to affect human safety for use of the WPC.