Effect of malathion on reproductive system of male rats

The pesticides are one of the most potentially harmful chemicals liberated in the environment in an unplanned manner Malathion is widely used as a potent pesticide in many countries and has been shown to produce some adverse health effects. A study was conducted to asses the effects of malathion on the male reproductive system of wistar rats. The pesticide was administered to rats orally at dose levels of 50, 150 and 250 mg/kg/body wt/day for 60 days. In comparison to the control rats, there was a significant reduction in the weight of testes, epididymis, seminal vesicle and ventral prostate. Testicular and epididymal sperm density were decreased in the animals treated with malathion. Pre and post fertility test showed 80% negative results after treatment Biochemical profile of the testis revealed a significant decline in the contents of sialic acid and glycogen. Whereas a significant increase in the protein content of testis and testicular cholesterol was observed. The activity of testicular enzyme acid phosphatase increased significantly while decreased alkaline phosphatase activity was found. Malathion also suppressed the level of testosterone significantly Results of the present study clearly suggest that malathion induce toxic effects on the male reproductive system of rats.     

Evaluation of antifouling activity of eight commercially available organic chemicals against the early foulers marine bacteria and Ulva spores

Environmental impacts caused by tin and copper based commercial antifouling (AF) paints were proved to be detrimental to aquatic ecosystems. Therefore, a search of environmental friendly AF compounds to be used in marine paint to protect the surface of maritime developmental structures from the unwanted biofouling is a burning issue of the present time. Commercially available eight organic chemicals--allyl isothiocyanate, beta-myrecene, cis-3-hexenyl acetate, citral, ethyl heptanoate, eugenol, methyl caproate, and octyl alcohol were evaluated forAF activities using both laboratory and field assays. The test chemicals were found to repel the target motile marine bacteria--Alteromonas marina, Bacillus atrophaeus, Roseobactergallaeciensis and Shewanella oneidensis and motile spores of the green alga, Ulva pertusa. The bacterial and Ulva spore repulsion activities of the test chemicals were measured by chemotaxis and agar diffusion methods respectively interestingly these test chemicals were less toxic to the test fouling species. The toxicity of the test chemicals was measured by using antibiotic assay disks against the bacteria and motility test against Ulva spores. Moreover, in field assay, all test chemicals showed a perfect performance ofAF activity showing no fouling during the experimental period of one year Such results and commercial as well as technical feasibility of the test chemicals firmly showed the possibility of using as alternatives of the existing toxic AF agents.     

Do the poor have what they need to adapt to climate change? A case study of Nepal

Nepal's geographical landscape of plains, hills, and mountains exposes it to severe climatic conditions. Out of the three regions, the plain, also called Terai, has the greatest risk of flooding, especially during the monsoon season when heavy precipitation coincides with snow and glacier melting from the mountains and hills. In recent years, greater water availability has increased the frequency of flooding, destroying farms, livestock, and infrastructure, hence, reducing agricultural productivity and disrupting economic activities. What makes Nepal a unique case study for climate change is its richness in water resources, propensity to flood, the percentage of poor people living in the flood prone region, and their dependency on natural resources. The lessons drawn can help when formulating pro-poor adaptation policies for other Asian and many developing countries that are as diverse, poor, and agrarian as Nepal. Using data collected through survey interviews, the study examines the ability of the poor to adapt to climate change. The study also explores the adaptive capacity of communities in the Koshi Tappu area, by examining whether or not they have the required capital assets (human, social, natural, physical, and financial capital) to remain resilient in the face of continuous climate events impacts.     

Impacts of vineyard area dynamics on soil erosion in a Mediterranean catchment (1950-2011)

The Mediterranean basin has undergone widespread land cover change. Urbanization of coastal areas, land abandonment of steeper slopes, and agricultural intensification in alluvial plains are recurrent themes. The objective of this study was to examine how vineyard land cover changes have affected agricultural soil erosion in a 50 year period (1950–2011). The study area covers a 235 km² catchment located near the Gulf of St Tropez. Aerial photographs were used to map land cover in 1950, 1982, 2003 and 2011, and the RUSLE soil erosion model was run to estimate soil erosion.

Between 1950 and 2011, vineyard went from about 2,426 ha to 1,561 ha. Mean soil erosion increased as vineyard slopes became steeper (11.8 T ha^?1, 13.2 T ha^?1, 14.4 T ha^?1 and 13.5 T ha^?1 for 1950, 1982, 2003 and 2011). Total erosion decreased after 1982: 28,621 T y^?1 in 1950, 29,030 T y^?1 in 1982, 22,848 T y^?1 in 2003, and 21,074 T y^?1 in 2011. Total soil loss in 2011 is about 75% of values in 1950–1982, so impacts on water pollution and channel dredging have evolved positively over time.     

Simple Arrhenius-type function accurately predicts dissolved oxygen saturation concentrations in aquatic systems

A sufficient supply of dissolved oxygen (DO) is vital for life in higher organisms. In aquatic systems, oxygen regulates respiratory metabolism, mediates biogeochemical cycles, and is an integral component of water quality. In this work, a simple predictive tool for dissolved oxygen saturation concentrations in aquatic systems as a function of chloride concentration and temperature using a novel Arrhenius-type asymptotic exponential function has been formulated. The proposed method predicts the amount of dissolved oxygen saturation concentrations for temperatures up to 50 °C and chloride concentrations up to 25 g/l. Estimations are found to be in excellent agreement with the reliable data in the literature with average absolute deviation being 3%. The tool developed in this study can be of immense practical value for the engineers and scientists to have a quick check on the oxygen saturation concentrations in aquatic systems at various conditions without opting for any experimental measurements. In particular, environmental science experts would find the proposed approach to be user-friendly with transparent calculations involving no complex expressions.     

External and internal carbonic anhydrases in Dunaliella species

Four species of Dunaliella and a carbonic anhydrase deficient mutant of Dunaliella tertiolecta (Butcher), HL 25/8, developed a process for concentrating dissolved inorganic carbon when adapted on air or low CO₂ for 24 h in the light. However, the external carbonic anhydrase activities in Dunaliella species were nil or low compared with those in Chlamydomonas reinhardtii (Danegard) or some Chlorella species. D. tertiolecta had low and about equal levels of external and internal carbonic anhydrase. D. parva (Lerche) and the D. tertiolecta mutant had negligible external carbonic anhydrase. D. viridis (Teodoresco) and D. salina (Teodoresco), high salt tolerant species, had high activities of intenal carbonic anhydrase but low levels of external carbonic anhydrase. Antiserum prepared against the 37 kDa peptide of extracellular carbonic anhydrase from Chlamydomonas reinhardtii was immunoreactive with a polypeptide of 30 kDa in D. tertiolecta and its salt sensitive external carbonic anhydrase (CA) mutant HL 25/8. External CA activity from D. tertiolecta was stimulated about three-fold, by including 0.5 M NaCl in the assay medium, while internal CA was not significantly affected by NaCl. External CA activities in the other species were insensitive to NaCl, while their internal activities were 90% inhibited by 0.5 M NaCl. Sorbitol only partly replaced NaCl in stimulating the external CA from D. tertiolecta. These experiments were performed with Dunaliella spp. grown in controlled laboratory cultures during September through November 1989.     

Nitrous oxide emissions in nonflooding period from fallow paddy fields

The study was conducted to investigate the N2O emissions and dissolved N2O in the leachate during the nonflooding period in nongrowing paddy fields.Three kinds of paddy soils were repacked to soil columns and were supersaturated with water initially and dried gradually in a greenhouse to attain the N2O emissions flux during the incubation.Soils with the texture of silty clay-loam (Q and H) produced cracks during the drying of soil,but soil with the texture of silty loam (X) did not form the cracks.Cracked s...     

New method accurately predicts carbon dioxide equilibrium adsorption isotherms

Among the methods that are being developed to date for CO₂ capture and separation, carbon dioxide adsorption is of great interest due to its low energy consumption, low equipment cost and easiness for application. In this work, a simple method which is easier than existing approaches requiring more complicated and longer computations is presented to accurately predict the carbon dioxide adsorption isotherms for a microporous material as a function of temperature and partial pressure of carbon dioxide. The method appears promising and can be extended for CO₂ capture as well as for separation of wide range of adsorbents and microporous materials including several molecular sieves merely by the quick readjustment of tuned coefficients. The proposed method showed consistently accurate results across the proposed pressure and temperature ranges. Predictions showed an average absolute deviation of 1.4% compared to existing Sips and Langmuir equations which show an average absolute deviations of 2.3% and 4%, respectively. The proposed method is superior owing to its accuracy and clear numerical background, wherein the relevant coefficients can be retuned quickly for various cases. This simple-to-use approach can be of immense practical value for the engineers and scientists to have a quick check on adsorption capacities of a given adsorbent at various temperatures and pressures without the necessity of any experimental measurements. In particular, personnel dealing with regulatory bodies of greenhouse gas control and process industries would find the proposed approach to be user friendly involving transparent calculations with no complex expressions.     

Evaluation of a sustainable remediation option: Beneficial reuse of petroleum-contaminated sediment as an energy source

The characteristics of petroleum-contaminated sediment (PCS) have been evaluated to assess whether the practice of its beneficial reuse as a sole or supplemental energy source is sustainable relative to other sediment remediation options such as monitored natural recovery (MNR), capping, or off-site disposal. Some of these remediation options for PCS are energy-intensive and/or require land utilization. The energy and compositional analysis results indicate a low carbon content (15–17%(wt)) and corresponding low energy values of 5,200 kJ/kg (2,200 Btu/lb) to 5,600 kJ/kg (2,400 Btu/lb). However, given other decision-making criteria, the sediment may contain enough value to be added as a supplemental fuel given that it is normally considered a waste product and is readily available.

The thermogravimetric profiles obtained under both combustion and pyrolytic conditions showed that the sulfur contents were comparable to typical low sulfur bituminous or lignite coals found in the United States, and most of the volatiles could be vaporized below 750°C. The heavy metal concentrations determined before and after combustion of the PCS indicated that further engineering controls may be required for mercury, arsenic, and lead. Due to the potential for reduction of public health and environmental threats, potential economic savings, and conservation of natural resources (petroleum and land), removal of PCS by dredging and beneficial reuse as a supplemental fuel clearly has merit to be considered as a sustainable remediation option.

Implications: This study will provide a logical evaluation process to determine whether petroleum-contaminated sediment can be reused as an energy source. The energy and emissions values were determined and evaluated whether the sediment could be combusted for viable and sustainable use, considering several factors pertinent to evaluate in the remediation decision process. Various analysis methods were employed to determine elemental compositions, heating values, thermal and emission characteristics. This evaluation process may be used as a general methodology for the determination of petroleum-contaminated sediment as a supplemental fuel that may have merit to be considered as a sustainable remediation option.     

Toxicity and degradation of the insecticide monocrotophos

Environmental Chemistry Letters - Monocrotophos, commonly named Azodrin or Nuvacron, is an organophosphate insecticide, which in spite of ban is preferred due to its high efficacy against...