Association of serum lead and mercury level with cardiometabolic risk factors and liver enzymes in a nationally representative sample of adolescents: the CASPIAN-III study

This study aims to determine the difference of serum Pb and Hg levels in adolescents with or without metabolic syndrome (MetS) and the association of serum levels of these heavy metals with cardiometabolic risk factors and liver enzymes in Iranian adolescents. The study population consisted of 320 adolescents (160 with MetS and 160 healthy controls). The relationship between serum heavy metals and cardiometabolic risk factors was assessed by linear regression. The odds ratios (OR) of having metabolic syndrome across Pb and Hg quartiles were determined by multiple logistic regression analysis. The mean (SD) of Pb and Hg concentrations were higher in adolescents with MetS than in those without it (0.83 (0.27) and 0.17 (0.01) vs. 0.65 (0.15) and 0.10 (0.08)?μg/L, P?=?0.01 and 0.0001, respectively). Increase in serum Pb and Hg was associated with increase in some cardiometabolic risk factors. Among boys and girls, diastolic blood pressure (DBP), fasting blood glucose, total cholesterol (TC), triglycerides (TG), and alanine aminotransaminase increased significantly across quartiles of serum Pb. Among girls, SBP, DBP, TC, and TG had a significant increase across Hg quartiles. The corresponding figure among boys was significant for SBP, DBP, and TG. Higher quartiles of Pb increased the risk of having MetS (OR 95 % CI 3.10, 2.25–4.27), the corresponding figure was 2.03, 1.75–3.16, across Hg quartiles. Our study showed significant associations between serum Pb and Hg levels with cardiometabolic risk factors in adolescents. In future surveys, the role of potential confounders should be considered more extensively. The clinical significance of these findings needs to be confirmed in longitudinal studies. By considering the origins of chronic diseases from early life, controlling environmental pollutants should be considered as a health priority for primordial or primary prevention of noncommunicable diseases.     

Concentration and characterization of airborne particles in Tehran’s subway system

Particulate matter is an important air pollutant, especially in closed environments like underground subway stations. In this study, a total of 13 elements were determined from PM₁₀ and PM_2.5 samples collected at two subway stations (Imam Khomeini and Sadeghiye) in Tehran’s subway system. Sampling was conducted in April to August 2011 to measure PM concentrations in platform and adjacent outdoor air of the stations. In the Imam Khomeini station, the average concentrations of PM₁₀ and PM_2.5 were 94.4?±?26.3 and 52.3?±?16.5 μg m^?3 in the platform and 81.8?±?22.2 and 35?±?17.6 μg m^?3 in the outdoor air, respectively. In the Sadeghiye station, mean concentrations of PM₁₀ and PM_2.5 were 87.6?±?23 and 41.3?±?20.4 μg m^?3 in the platform and 73.9?±?17.3 and 30?±?15 μg m^?3, in the outdoor air, respectively. The relative contribution of elemental components in each particle fraction were accounted for 43 % (PM₁₀) and 47.7 % (PM_2.5) in platform of Imam Khomeini station and 15.9 % (PM₁₀) and 18.5 % (PM_2.5) in the outdoor air of this station. Also, at the Sadeghiye station, each fraction accounted for 31.6 % (PM₁₀) and 39.8 % (PM_2.5) in platform and was 11.7 % (PM₁₀) and 14.3 % (PM_2.5) in the outdoor. At the Imam Khomeini station, Fe was the predominant element to represent 32.4 and 36 % of the total mass of PM₁₀ and PM_2.5 in the platform and 11.5 and 13.3 % in the outdoor, respectively. At the Sadeghiye station, this element represented 22.7 and 29.8 % of total mass of PM₁₀ and PM_2.5 in the platform and 8.7 and 10.5 % in the outdoor air, respectively. Other major crustal elements were 5.8 % (PM₁₀) and 5.3 % (PM_2.5) in the Imam Khomeini station platform and 2.3 and 2.4 % in the outdoor air, respectively. The proportion of other minor elements was significantly lower, actually less than 7 % in total samples, and V was the minor concentration in total mass of PM₁₀ and PM_2.5 in both platform stations.     

CIELAB color variables as indicators of compost stability

The composting process of different organic wastes both in laboratory and on a large-scale was characterized using CIELAB color variables to evaluate compost stability for the better application in agriculture. The time courses of the CIELAB variables of composting materials were determined directly from the bottom of a glass petri dish filled with dried and ground samples using a Minolta Color Reader (CR-13) calibrated with clean empty petri dishes placed on a white tile. To compare the proposed method with conventional methods, the same materials were also evaluated using commonly used compost stability evaluation indices. Most of the CIELAB variables of a compost made from a mixture of green tea waste and rice bran reached a plateau after 84 days of composting and showed strong relationships with the commonly used compost stability evaluation indices. The time needed for CIELAB variables, especially the L*and b* values, to stabilize at large-scale composting plants of cattle litter, farmyard manure, kitchen garbage and bark compost, were more or less similar to the times of maturation evaluated by the respective compost producers. The CIELAB color variable offers a new, simple, rapid and inexpensive means of evaluating compost stability and its quality prior to agricultural use.     

Conclusion to the Featured Series on Satellites and Transboundary Water: Emerging Ideas1

Hossain, Faisal, 2010. Conclusion to the Featured Series on Satellites and Transboundary Water: Emerging Ideas. Journal of the American Water Resources Association (JAWRA) 46(4): 663-664. DOI: 10.1111/j.1752-1688.2010.00449.x     

Evaluation of PCA and Gamma test techniques on ANN operation for weekly solid waste prediction

Artificial neural networks (ANNs) are suitable for modeling solid waste generation. In the present study, four training functions, including resilient backpropagation (RP), scale conjugate gradient (SCG), one step secant (OSS), and Levenberg–Marquardt (LM) algorithms have been used. The main goal of this research is to develop an ANN model with a simple structure and ample accuracy. In the first step, an appropriate ANN model with 13 input variables is developed using the afore-mentioned algorithms to optimize the network parameters for weekly solid waste prediction in Mashhad, Iran. Subsequently, principal component analysis (PCA) and Gamma test (GT) techniques are used to reduce the number of input variables. Finally, comparison amongst the operation of ANN, PCA-ANN, and GT-ANN models is made. Findings indicated that the PCA-ANN and GT-ANN models have more effective results than the ANN model. These two models decrease the number of input variables from 13 to 7 and 5, respectively.     

The use of date palm as a potential adsorbent for wastewater treatment: a review

Background

In tropical countries, the palm tree is one of the most abundant and important trees. Date palm is a principal fruit grown in many regions of the world. It is abundant, locally available and effective material that could be used as an adsorbent for the removal of different pollutants from aqueous solution.

Review

This article presents a review on the role of date palm as adsorbents in the removal of unwanted materials such as acid and basic dyes, heavy metals, and phenolic compounds. Many studies on adsorption properties of various low cost adsorbent, such as agricultural waste and activated carbons based on agricultural waste have been reported in recent years.

Conclusion

Studies have shown that date palm-based adsorbents are the most promising adsorbents for removing unwanted materials. No previous review is available where researchers can get an overview of the adsorption capacities of date palm-based adsorbent used for the adsorption of different pollutants. This review provides the recent literature demonstrating the usefulness of date palm biomass-based adsorbents in the adsorption of various pollutants.     

Impact of nano-CuO stress on rice (Oryza sativa L.) seedlings

Indiscriminate release of metal oxide nanoparticles (NPs) into the environment due to anthropogenic activities has become a serious threat to the ecological system including plants. The present study assesses the toxicity of nano-CuO on rice (Oryza sativa cv. Swarna) seedlings. Three different levels of stress (0.5 mM, 1.0 mM and 1.5 mM suspensions of copper II oxide, <50 nm particle size) were imposed and seedling growth performance was studied along control at 7 and 14 d of experiment. Modulation of ascorbate–glutathione cycle, membrane damage, in vivo ROS detection, foliar H₂O₂ and proline accumulation under nano-CuO stress were investigated in detail to get an overview of nano-stress response of rice. Seed germination percentage was significantly reduced under stress. Higher uptake of Evans blue by nano-CuO stressed roots over control indicates loss of root cells viability. Presence of dark blue and deep brown spots on leaves evident after histochemical staining with NBT and DAB respectively indicate severe oxidative burst under nano-copper stress. APX activity was found to be significantly increased in 1.0 and 1.5 mM CuO treatments. Nevertheless, elevated APX activity might be insufficient to scavenge all H₂O₂ produced in excess under nano-CuO stress. That may be the reason why stressed leaves accumulated significantly higher H₂O₂ instead of having enhanced APX activity. In addition, increased GR activity coupled with isolated increase in GSH/GSSG ratio does not seem to prevent cells from oxidative damages, as evident from higher MDA level in leaves of nano-CuO stressed seedlings over control. Enhanced proline accumulation also does not give much protection against nano-CuO stress. Decline in carotenoids level might be another determining factor of meager performance of rice seedlings in combating nano-CuO stress induced oxidative damages.     

Linear and non-linear relationships mapping the Henry’s law parameters of organic pesticides

This work aims to predict the air to water partitioning for 96 organic pesticides by means of the Quantitative Structure–Property Relationships Theory. After performing structural feature selection with Genetics Algorithms and Replacement Method linear approaches, it is found that among the most important molecular features appears the Moriguchi octanol–water partition coefficient, and higher lipophilicities would lead to compounds having higher Henry’s law constants. We also compare the statistical performance achieved by four fully-connected Feed-Forward Multilayer Perceptrons Artificial Neural Networks. The statistical results found reveal that the best performing model uses the Levenberg–Marquardt with Bayesian regularization (BR) weighting function for achieving the most accurate predictions.     

Food security and ecological footprint of coastal zone of Bangladesh

This paper presents the present status of food security and ecological footprint, an indicator of environmental sustainability of the coastal zones of Bangladesh. To estimate the present status of the food security and ecological footprint of the coastal zone of Bangladesh, primary and secondary data were collected, and the present status of food security and environmental degradation (in terms of ecological footprint) were calculated. To estimate the household food security, primary data were also collected from all the households in a representative selected village. A quantitative method for computation of food security in grain equivalent based on economic returns (price) is developed, and a method of measuring sustainable development in terms of ecological footprint developed by Wackernagel is used to estimate the environmental sustainability (Wackernagel and Rees in Our ecological footprint: reducing human impact on the earth. New Society, Gabrioala, BC, 1996; Chambers et al. in Sharing nature’s interest-ecological footprint as an indicator of sustainability. Earthscan, London, 2000). Overall status of food security at upazila levels is good for all the upazilas except Shoronkhola, Shyamnager and Morrelgonj, and the best is the Kalapara upazila. But the status of food security at household levels is poor. Environmental status in the coastal zones is poor for all the upazilas except Kalapara and Galachipa. The worst is in the Mongla upazila. Environmental status has degraded mainly due to shrimp culture. This study suggests that control measures are needed for affected upazilas and any further expansion of the shrimp aquaculture to enhance the food security must take into account the environmental aspects of the locality under consideration.     

Extended Analytical Turbulent Diffusion Model for Particle Dispersion and Deposition in a Horizontal Pipe: Comparison with CFD Simulation

A 2D analytical turbulent diffusion model for particle dispersion and deposition at different heights along the pipe flow and circumferential deposition has been developed. This liquid–solid turbulent diffusion model presented in this paper has emanated from an existing gas–liquid turbulent diffusion model. This model can be used as a handy tool for quick estimation one and two-dimensional deposition fluxes of particles in water distribution networks. A comprehensive 3D numerical investigation has been carried out using multiphase mixture model available in “Fluent 6.2” to verify the above analytical model. Different particles sizes and densities were used for 3D numerical investigations. The deposition was studied as a function of particle diameter, density, and fluid velocity. The deposition of particles, along the periphery of the pipe wall and at different depths, was investigated. Both the models findings matched with qualitative phenomena such as deposition of heavier particles at the bottom of the pipe wall were higher at lower velocities and lower at higher velocities. The lighter particles were found mostly suspended with homogeneous distribution. Smaller particles were also suspended with marginal higher concentration near the bottom of the pipe wall. This marginal higher concentration of the smaller particles was found to be slightly pronounced for lower velocity. These analogies of particles are well discussed with the ratio between free-flight velocity and the gravitational settling velocity. Extended analytical model results were compared with the 3D computational fluid dynamics simulation results. Discrepancies in the model results were discussed.