Uptake,translocation, and control of trumpet flower (Tecoma stans) with aminocyclopyrachlor

To gain a better understanding of the physiology of the herbicide aminocyclopyrachlor in young plants of trumpet flower, the uptake and translocation were evaluated after the application of herbicide. This was determined by treating individual leaves with formulated herbicides plus ¹⁴C-aminocyclopyrachlor after the application of the formulated herbicide. This experiment used a randomized experimental design with three replications. In addition, field studies were conducted to assess the effectiveness of foliar applications of aminocyclopyrachlor in association with metsulfuton-methyl. The plant absorbed 20% of the herbicide applied. The translocation percentage did not surpass 5% of the total amount applied. Only 1% of the herbicide applied was translocated to the roots. Rate of 40 + 13 g a.i. 100 L^?1 of aminocyclopyrachlor+metsulfuron-methyl was effective to control T. stans.     

Municipal solid waste shear strength parameters defined through laboratorial and in situ tests

This paper presents the parameters of municipal solid waste shear strength determined in the laboratory (triaxial tests) and by in situ tests: standard penetration tests (SPT) and cone penetration tests (CPT). The results analyzed here are part of a study carried out on the Santo Tirso landfill (north of Portugal) between 2001 and 2007. The influence of the strain levels, waste composition, and waste age on the shear strength parameters is presented, as well as an attempt to establish some correlations between the SPT and CPT tests and to estimate municipal solid waste (MSW) friction angles from the SPT tests. The results indicate that the aging of the waste, which is characterized by a decrease in fibrous and organic materials and an increase in inert materials and fine fraction, leads to an increase in frictional resistance and to a decrease in cohesion. The results of the SPT and CPT tests indicate higher penetration resistance in older and deeper waste. Estimating the frictional resistance from the SPT test seems to obey an empirical relationship expressed by a power function, which depends on the strain level.

Implications: Comparison of shear strength parameters of municipal solid waste (MSW) determined through laboratory (triaxial tests) and in situ tests (SPT and CPT) showed that the greater amount of fibrous and granular elements leads to an increase in “cohesion” and in friction angle values, respectively. Waste aging results in an increase in frictional resistance and in a decrease in “cohesive” resistance. This is consistent with the composition changes with aging: increase of the relative quantity of inert materials and fine fraction, and decrease in particle size, in organic matter content, and in fabrics and plastics.     

Chlorpyrifos acute exposure induces hyperglycemia and hyperlipidemia in rats

In this study we evaluated the hyperglycemic and hyperlipidemic effects of chlorpyrifos (CPF) after an acute exposure in rats. The mechanisms involved in hyperglycemia induced by CPF were studied. A single dose of CPF (50 mg kg⁻¹, subcutaneous, s.c.) was administered to overnight-fasted rats. Glucose and corticosterone levels, lipid status and paraoxonase (PON1) activity were determined in plasma of rats. Cardiovascular risk factors and the atherogenic index were calculated. Glycogen levels, tyrosine aminotransferase (TAT) and glucose-6-phosphatase (G6Pase) activities were determined in livers of rats. Cerebral acetylcholinesterase (AChE) activity was also determined. CPF caused an increase in glucose and glycogen levels as well as in TAT and G6Pase activities. The CPF exposure caused an increase in corticosterone levels, an inhibition of AChE activity and a reduction of PON1 activity. Regarding the lipid status, CPF induced an increase in triglycerides (TG) and low-density lipoprotein-cholesterol (LDL) levels and a decrease in high-density lipoprotein (HDL) levels associated with an increase of cardiovascular risk factors and the atherogenic index. The present study demonstrated that a single CPF administration caused hyperglycemia and hyperlipidemia in rats. The activation of the gluconeogenesis pathway, probably elicited by hypercorticosteronemia, is involved in the hyperglycemic effect of CPF in rats.     

Effects of impervious cover on the surface water quality and aquatic ecosystem of the Kyeongan stream in South Korea

The extent of impervious cover in a watershed has been linked to the quality of an urban aquatic environment. The Kyeongan watershed in South Korea was investigated to evaluate the relationship between the total impervious area (TIA) and the aquatic ecosystem of the watershed, including water quality and aquatic life using a relatively high-resolution (0.4 m) image. The TIA was found to be approximately 12% of the watershed, which indicates that the quality of its environment was being adversely affected by it. For water quality, Pearson correlation analyses showed that all water quality parameters studied were found to be positively correlated with TIA at p < 0.01, except for nitrate (NO3-). In addition, the zone with a higher TIA was found to have worse water quality. Some water quality parameters, such as nitrite (NO2-), total phosphorus, and phosphate (PO4(3-)) were highly affected by discharges from wastewater treatment plants. Water quality data suggest that TIA could be used to predict the water quality of streams. For ecological parameters, the diatom index for organic pollution and trophic diatom index were found to be highly correlated with TIA, whereas physical habitat and benthic macroinvertebrates were poorly correlated with TIA. However, the results indicate that the extent of impervious cover can be a useful indicator for predicting the status of specific ecosystem of streams.     

Diphenyl diselenide attenuates hepatic and hematologic toxicity induced by chlorpyrifos acute exposure in rats

Purpose

In this study, we investigated the effect of diphenyl diselenide [(PhSe)₂] on chlorpyrifos (CPF)-induced hepatic and hematologic toxicity in rats.

Methods

Rats were pre-treated with (PhSe)₂ (5?mg/kg) via the oral route (oral gavage) once a day for 7?days. On the eighth and ninth days, rats were treated with (PhSe)₂ (5?mg/kg) 30?min prior to CPF (50?mg/kg, by subcutaneous route). The aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase activities were determined in plasma of rats. Lipid peroxidation, protein carbonyl, and non-protein thiol levels as well as catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and gluthatione S-transferase activities were determined in livers of rats. Hematological parameters were also determined.

Results

The results showed that CPF caused hepatic oxidative damage, as demonstrated by an increase in lipid peroxidation and protein carbonyl levels which was associated with a decrease in antioxidant defenses. CPF exposure caused a reduction in the leukocyte, indicating hematologic toxicity. (PhSe)₂ was effective in attenuating these toxic effects caused by CPF exposure in rats.

Conclusions

The results indicated that (PhSe)₂ was effective in protecting the hepatic and hematologic toxicity induced by acute CPF exposure in rats.     

Conductive-diamond electrochemical oxidation of chlorpyrifos in wastewater and identification of its main degradation products by LC-TOFMS

The electrochemical transformation of the organophosphorous insecticide chlorpyrifos (CPF) was investigated in wastewater. The oxidation of CPF was carried out in a single-compartment electrochemical flow cell working under batch operation mode, using diamond-based material as anode and stainless steel as cathode. In order to evaluate its persistence and degradation pathway, two different concentration levels (1.0 mg L⁻¹ and 0.1 mg L⁻¹) were studied. Liquid chromatography/mass spectrometry was used for evaluation of the initial and electrolyzed solutions. The identification of CPF transformation products was performed by liquid chromatography-time of flight-mass spectrometry (LC-TOFMS). Results showed that CPF is completely removed at the end of treatment time. Analysis by LC-TOFMS allowed the identification of six degradation products (with Mw 154, 170, 197, 305 321 and 333). Three of the identified intermediates (Mw 170, 305 and 321) were completely removed at the end of electrolysis time. Interestingly, the formation of diethyl 3,5,6-trichloropyridin-2yl phosphate (chlorpyrifos oxon) and 3,5,6-trichloropyridin-2-ol was also found in previous reported degradation pathways using different degradation technologies.     

Pesticide residues in Portuguese strawberries grown in 2009–2010 using integrated pest management and organic farming

Pesticides are among the most widely used chemicals in the world. Because of the widespread use of agricultural chemicals in food production, people are exposed to low levels of pesticide residues through their diets. Scientists do not yet have a total understanding of the health effects of these pesticide residues. This work aims to determine differences in terms of pesticide residue content in Portuguese strawberries grown using different agriculture practices. The Quick, Easy, Cheap, Effective, Rugged, and Safe sample preparation method was conducted and shown to have good performance for multiclass pesticides extraction in strawberries. The screening of 25 pesticides residue was performed by gas chromatography?Ctandem mass spectrometry. In quantitative validation, acceptable performances were achieved with recoveries of 70?C120 and <12?% residual standard deviation for 25 pesticides. Good linearity was obtained for all the target compounds, with highly satisfactory repeatability. The limits of detection were in the range of 0.1?C28???g/kg. The method was applied to analyze strawberry samples from organic and integrated pest management (IPM) practices harvested in 2009?C2010. The results showed the presence of fludioxonil, bifenthrin, mepanipyrim, tolylfluanid, cyprodinil, tetraconazole, and malathion when using IPM below the maximum residue levels.     

The bioaccumulation and translocation of Fe,Zn, and Cu in species of mushrooms from <Emphasis Type="Italic">Russula</Emphasis> genus

Introduction  

Many previous studies revealed a high ability of mushrooms to accumulate heavy metals from environment. This paper concerns the capacity of some wild macromycetes belonging to Russula genus to accumulate heavy metals in natural condition of pH (between 6.5 and 6.8) and the pattern of metal translocation in the fruiting body.     

Waste management activities and carbon emissions in Africa

This paper summarizes research into waste management activities and carbon emissions from territories in sub-Saharan Africa with the main objective of quantifying emission reductions (ERs) that can be gained through viable improvements to waste management in Africa. It demonstrates that data on waste and carbon emissions is poor and generally inadequate for prediction models. The paper shows that the amount of waste produced and its composition are linked to national Gross Domestic Product (GDP). Waste production per person is around half that in developed countries with a mean around 230 kg/hd/yr. Sub-Saharan territories produce waste with a biogenic carbon content of around 56% (+/−25%), which is approximately 40% greater than developed countries. This waste is disposed in uncontrolled dumps that produce large amounts of methane gas. Greenhouse gas (GHG) emissions from waste will rise with increasing urbanization and can only be controlled through funding mechanisms from developed countries.     

Phosphorus effect on Zn adsorption-desorption kinetics in acid soils

The adsorption-desorption kinetics of Zn in the absence and presence of P was studied by using the stirred flow chamber technique. The results thus obtained were compared with those previously obtained for Cu. As with copper, the simultaneous addition of P and Zn in a 1:1 mole ratio to soil was found to significantly increased Zn adsorption relative to the absence of P. Unlike Cu, however, Zn was only adsorbed at fast adsorption sites in the absence of P. In any case, the increased adsorption of Zn in the presence of P was largely due to slow adsorption sites, where Zn²⁺ ion acted as a bridging element between P and organic matter. Following adsorption in both the presence and absence of P, Zn was desorbed to a much higher extent than was Cu. However, the proportion of Zn desorbed after adsorption in the presence of P was significantly lower than in the absence of P. This indicates that Zn binds more strongly to adsorbing surfaces in the presence of P than in its absence.