Evaluation of potential dermal exposure of pesticide spray operators in greenhouses by use of visible tracers

In the present study, the potential dermal and inhalation exposure of the operator was measured, following simulation of insecticide application with the dye tracer Sunset Yellow in greenhouse cucumbers and tomatoes. For the monitoring of operator exposure, the whole body technique was used. The potential inhalation exposure was measured with a personal air sampler equipped with a glass fiber filter. The potential dermal operator exposure ranged from 84.4 to 526.7 ml of spray solution (s.s.)/h for the whole body and from 18.5 to 62.5 ml s.s./h for hands in the case of greenhouse cucumbers. The respective inhalation exposure was between 0.17 and 1.0 ml s.s./h. For greenhouse tomatoes, the potential body exposure was in the range of 22.4 to 62.1 ml s.s./h. The hand exposure varied from 5.5 to 6.1 ml s.s./h. The potential inhalation exposure was in the range of 0.33 to 0.43 ml s.s./h. The potential dermal operator exposure is a highly variable parameter, with a variation factor higher than 100% in many cases. One of the most critical factors for the determination of both potential dermal and inhalation exposure is the application pressure. Other field and operational conditions, including unpredictable factors, are also important for the determination of operator exposure levels. The measured potential dermal operator exposure values were above the levels of exposure estimated with mathematical models.     

Bayesian analysis of Jolly-Seber type models

We propose the use of finite mixtures of continuous distributions in modelling the process by which new individuals, that arrive in groups, become part of a wildlife population. We demonstrate this approach using a data set of migrating semipalmated sandpipers (Calidris pussila) for which we extend existing stopover models to allow for individuals to have different behaviour in terms of their stopover duration at the site. We demonstrate the use of reversible jump MCMC methods to derive posterior distributions for the model parameters and the models, simultaneously. The algorithm moves between models with different numbers of arrival groups as well as between models with different numbers of behavioural groups. The approach is shown to provide new ecological insights about the stopover behaviour of semipalmated sandpipers but is generally applicable to any population in which animals arrive in groups and potentially exhibit heterogeneity in terms of one or more other processes.     

Cx43 regulates mechanotransduction mechanisms in human preterm amniotic membrane defects

Objective

The effects of mechanical stimulation in preterm amniotic membrane (AM) defects were explored.

Methods

Preterm AM was collected from women undergoing planned preterm caesarean section (CS) due to fetal growth restriction or emergency CS after spontaneous preterm prelabour rupture of the membranes (sPPROM). AM explants near the cervix or placenta were subjected to trauma and/or mechanical stimulation with the Cx43 antisense. Markers for nuclear morphology (DAPI), myofibroblasts (αSMA), migration (Cx43), inflammation (PGE₂) and repair (collagen, elastin and transforming growth factor β [TGFβ₁]) were examined by confocal microscopy, second harmonic generation, qPCR and biochemical assays.

Results

In preterm AM defects, myofibroblast nuclei were highly deformed and contractile and expressed αSMA and Cx43. Mechanical stimulation increased collagen fibre polarisation and the effects on matrix markers were dependent on tissue region, disease state, gestational age and the number of fetuses. PGE₂ levels were broadly similar but reduced after co-treatment with Cx43 antisense in late sPPROM AM defects. TGFβ₁ and Cx43 gene expression were significantly increased after trauma and mechanical stimulation but this response dependent on gestational age.

Conclusion

Mechanical stimulation affects Cx43 signalling and cell/collagen mechanics in preterm AM defects. Establishing how Cx43 regulates mechanosignalling could be an approach to repair tissue integrity after trauma.     

Primary and secondary organic aerosol in an urban/industrial site: Sources, health implications and the role of plastic enriched waste burning

PM10 samples were collected from an urban/industrial site nearby Athens, where uncontrolled burning activities occur. PAHs, monocarboxylic, dicarboxylic, hydroxycarboxylic and aromatic acids, tracers from BVOC oxidation, biomass burning tracers and bisphenol A were determined. PAH, monocarboxylic acids, biomass burning tracers and bisphenol A were increased during autumn/winter, while BSOA tracers, dicarboxylic- and hydroxycarboxylic acids during summer. Regarding aromatic acids, different sources and formation mechanisms were indicated as benzoic, phthalic and trimellitic acids were peaked during summer whereas p-toluic, isophthalic and terephthalic were more abundant during autumn/winter. The Benzo[a]pyrene-equivalent carcinogenic power, carcinogenic and mutagenic activities were calculated showing significant (p < 0.05) increases during the colder months. Palmitic, succinic and malic acids were the most abundant monocarboxylic, dicarboxylic and hydrocarboxylic acids during the entire sampling period. Isoprene oxidation was the most significant contributor to BSOA as the isoprene-SOA compounds were two times more abundant than the pinene-SOA (13.4 ± 12.3 and 6.1 ± 2.9 ng/m³, respectively). Ozone has significant impact on the formation of many studied compounds showing significant correlations with: isoprene-SOA (r = 0.77), hydrocarboxylic acids (r = 0.69), pinene-SOA (r = 0.63),dicarboxylic acids (r = 0.58), and the sum of phthalic, benzoic and trimellitic acids (r = 0.44). PCA demonstrated five factors that could explain sources including plastic enriched waste burning (30.8%), oxidation of unsaturated fatty acids (23.0%), vehicle missions and cooking (9.2%), biomass burning (7.7%) and oxidation of VOCs (5.8%). The results highlight the significant contribution of plastic waste uncontrolled burning to the overall air quality degradation.     

Impact of shipping emissions on ozone levels over Europe: assessing the relative importance of the Standard Nomenclature for Air Pollution (SNAP) categories

Environmental Science and Pollution Research - The impact of shipping emissions on ozone mixing ratio over Europe is assessed for July 2006 using the Community Multiscale Air Quality modeling...     

The use of tailor-made acidic deep eutectic solvents for preparation of quercetin-enriched extracts from onion solid wastes

The current examination dealt with the development of a methodology to produce quercetin, a multifunctional bio-flavonoid, by designing task-specific, highly acidic deep eutectic solvents, based on glycerol and natural organic acids. The purpose was to achieve a simultaneous hydrolysis of spiraeoside, the major quercetin glycoconjugate occurring in onion solid wastes, and quercetin extraction. After an initial performance screening, the combination of glycerol/oxalic acid was identified as the highest-performing system, and further investigation showed that the most efficacious molar ratio was glycerol/oxalic acid 3:1. Further study of hydrolysis/extractions conditions suggested 30 min, at 130°C, to be the best operating conditions, giving the highest yield of 19.65 mg quercetin per grams of dry mass. The extract obtained under these conditions displayed significantly enhanced antiradical activity, compared to control extracts prepared with water or aqueous ethanol. On the other hand, results on the ferric-reducing power were rather contradictory. It is proposed that such a methodology may be implemented to valorize onion solid wastes, for the production of extracts significantly enriched in quercetin, with increased antiradical properties.     

Increasing extremes of heat and drought associated with recent severe wildfires in southern Greece

Mountains of the northern Mediterranean basin face two major threats under global change. Aridity and available fuel are both expected to increase because of climatic and land-use changes, increasing fire danger. There may already be signs of such effects in the case of the Pinus nigra and Abies cephalonica forests on Mt. Taygetos (southern Greece). We reconstructed climate (mid- to late-fire-season drought) using tree-rings for the last 150 years and compared it with the mountain’s fire history reconstructed from P. nigra fire scars. Seven, out of the ten, large fires Mt. Taygetos experienced were associated with below-normal precipitation (P) or above-normal maximum temperature (T _max). The largest fires occurred in late summer of 1879, 1944, 1998, and 2007. However, only the recent fires (1998 and 2007) had both low P and high T _max, also confirmed from long-term meteorological data. The synergy between climate and fuel availability may explain the very high intensity of 1998 and 2007 fires that burned mostly as stand-replacing crown fires. The other two large fire events (1879 and 1944) most likely occurred under reduced availability in burning fuel and were related to above-normal T _max. Our findings are among the first based on long-term and site-specific empirical data to support the prediction that Mediterranean mountainous areas will face a very large threat from wildfires in the twenty-first century, if socioeconomic changes leading to land abandonment and thus burning fuel accumulation are combined with the drought intensification projected for the region under global warming.     

MOSESS: A New Emission Model for the Compilation of Model-Ready Emission Inventories—Application in a Coal Mining Area in Northern Greece

Over the last years, the capabilities of chemical transport models have been greatly improved and the need for more accurate emission data has increased as well. In the past, a number of emission models have been developed and present different functionalities and applications. The majority of these though cover very specific needs. This paper describes the development of a new emission model namely computer model for the construction of model-ready emission inventories (MOSESS) which is used to compile high-resolution emission inventories or improve existing ones, utilizing complex GIS techniques. The model aims in helping chemical modelers to obtain a better overview of their modeling application by having a comprehensive understanding of the emission input. MOSESS incorporates more than 70 different emission calculation methodologies, and it is capable of handling external emission databases (such as EMEP and EPER) from which emissions can be extracted. The temporal variation (annual/daily and diurnal processing), chemical speciation of NMVOCs and particles, vertical distribution and point source treatment, as well as the spatial disaggregation of emissions (utilizing numerous spatial proxies including high-resolution landuses) can help create model-ready emission inventories which can be used for contemporary modeling applications.