Environmental human silver exposure

Environmental exposure to silver (Ag) was assessed in occupationally non-exposed adult human population by analyzing Ag in the hair (H?·?Ag) and whole blood (WB?·?Ag). H?·?Ag was analyzed in 311 (123 men, M; 188 women, W); while WB?·?Ag was determined in 235 of these individuals (90 M, 145 W). Women had more H?·?Ag than men (M 0.05 vs. W 0.076), whereas WB?·?Ag concentrations in men and women were not significantly different. A natural distribution of the median derivatives was utilized to generate the dataset to fit the logistic sigmoid curve to assess the current human body burden of environmental Ag population exposure for M and W separately. The H?·?Ag (µg?g^?1) below 0.0105 for M and 0.0145 for W, reflects low level of environmental Ag exposure. The adaptive physiological saturation phase followed where H?·?Ag rose rapidly, first for M and then for W in parallel with biological assay. Both parallel saturation curves converged and plateaued at 0.215 for M and 0.965 for W (µg?g^?1). The current level of human environmental Ag exposure is low, but cases of high Ag exposure occurred sporadically. In conjunction with the medical histories overt clinical neural toxicity may be expected for H?·?Ag at 4?µg?g^?1and higher. There were no significant correlation between the H?·?Ag and WB?·?Ag.     

Biohythane production from pineapple peel using Methanosarcina mazei enhanced with palm oil mill effluent (POME) sludge in single-stage anaerobic digestion

Biohythane production via single-stage anaerobic digestion (AD) is an effective way for sustainable energy recovery from lignocellulosic biomass. In this paper, biohythane was produced through the AD process from pineapple peel waste substrate using purely cultured Methanosarcina mazei with the enhancement of palm oil mill effluent (POME) sludge as the inoculum. This study focuses on the effects of the lignocellulosic pre-treatment method, the addition of POME sludge into M. mazei culture medium as inoculum, and various operational conditions (food to microorganisms (F/M) ratios, temperature, pH) on gas production performances. The experimental results indicate that these parameters influenced the efficiency of biohythane production by producing the peak maximum biohythane production rate values (HPR_max) and (MPR_max), H₂:CH₄ = 1.93:0.67 L/L-d, and biohythane yield (HY) and (MY), H₂:CH₄ = 1.18:0.55 mL/L-substrate. This study demonstrates that biohythane gas (H₂ + CH₄ + CO₂) production from pineapple waste can be accelerated by M. mazei only with the enhancement of POME sludge through single-stage AD system under mesophilic batch process conditions.     

Eco-assessment of streams of Konya closed river basin (Turkey) using various ecoregional diatom indices

Ecological assessment of freshwater ecosystems based on diatom metrics is an important issue for attaining environmental sustainability. The present study aimed to evaluate differences in the diatom–stressor relationship in relatively least disturbed streams in the Konya closed river basin using multivariate analyses and to bio-assess streams by the application of different ecoregional diatom indices. Cocconeis euglypta, Cymbella excisa, Cocconeis placentula, and Achnanthidium minutissimum are the most contributing species to the dissimilarity of sampling stations between rainy (spring) and dry (summer and fall) seasons and also between altitude (A2 800- < 1600 m and A3 ≥ 1600 m) groups. The first two axes of canonical correspondence analysis revealed a significant (82.8%) relationship between diatom species and stressors. Diatom species displayed distinct responses to environmental variables (electrical conductivity, Ni, Cu, B, and altitude) playing important roles on the distribution of species. Diatom indices indicate different ecological statuses of stations, from bad to high. European diatom indices except Duero Diatom Index (DDI) and Trophic Diatom Index (TDI) showed good responses to the eco-assessment of streams and indicated high ecological status for the least disturbed sampling stations symbolized as S16, S20, S24, S25, S27-29, S37, and S39. These results were also supported by abiotic evaluation. Although TIT was more competitive in the bio-assessment of streams among diatom indices, it is necessary to increase its species list by determining their trophic weights in future studies. Therefore, the use of ecoregion-specific diatom indices is suggested along with increasing the number of used species to correctly interpret the water quality.

Graphical Abstract

     

Testing the performance of European diatom indices for evaluating the ecological status in the Kızılırmak basin,Turkey: flowing waters

Environmental Science and Pollution Research - The K?z?l?rmak River is the longest river (1.355 km) in Turkey and flows into the Black Sea. Main pressures in the basin are waste...     

A decision support system for assessing landfill performance

Designing environmentally sound landfills is a challenging engineering task due to complex interactions of numerous design variables; such as landfill size, waste characteristics, and site hydrogeology. Decision support systems (DSS) can be utilized to handle these complex interactions and to aid in a performance-based landfill design by coupling system simulation models (SSM). The aim of this paper is to present a decision support system developed for a performance-based landfill design. The developed DSS is called Landfill Design Decision Support System – LFDSS. A two-step DSS framework, composed of preliminary design and detailed design phases, is set to effectively couple and run the SSMs and calculation modules. In preliminary design phase, preliminary design alternatives are proposed using general site data. In detailed design phase, proposed design alternatives are further simulated under site-specific data using SSMs for performance evaluation. LFDSS calculates the required landfill volume, performs landfill base contour design, proposes preliminary design alternatives based on general site conditions, evaluates the performance of the proposed designs, calculates the factor of safety values for slope stability analyses, and performs major cost calculations. The DSS evaluates the results of all landfill design alternatives, and determines whether the design satisfies the predefined performance criteria. The DSS ultimately enables comparisons among different landfill designs based on their performances (i.e. leachate head stability, and groundwater contamination), constructional stability and costs. The developed DSS was applied to a real site, and the results demonstrated the strengths of the developed system on designing environmentally sound and feasible landfills.     

Solid-phase extraction of Mn(II) and slurry analysis of the sorbent by electrothermal atomic absorption spectrometry

In this study, a challenging preconcentration/separation method based on the sorption of manganese on ethylene glycol dimethacrylatemethacrylic acid copolymer (EGDMA-MA) treated with ammonium pyrrolidine dithiocarbamate (APDC) and its slurry analysis by electrothermal atomic absorption spectrometry was described. Optimum conditions for quantitative sorption, as well as for preparing a homogeneous and stable slurry were investigated. A 100-fold enrichment factor could be reached. The analyte element in certified sea-water and bovine-liver samples were determined in the range of 95% confidence level. The proposed technique is fast, simple, and the risk of contamination is low. The limit of detection of the method for manganese in the slurry of the blank subjected to the proposed procedure was 0.07 μg L^?1 (3δ, N:10) corresponding to 0.56 μg kg^?1 slurry.     

Comparison of fecal coliform bacteria before and after wastewater treatment plant in the Izmir Bay (Eastern Aegean Sea)

The distribution of fecal coliforms was investigated and determined in Izmir Bay from 1996 to 2005. Izmir Bay severely was polluted from industrial and domestic discharges during decades. In early 2000, a wastewater treatment plant began to treat domestic and industrial wastes. This plant treats the wastes about 80% capacity after 2001. The sampling periods cover before and after treatment plant. Assessment method for determining the number of fecal coliform has evolved membrane filtrations. Maximum surface fecal coliform concentration was 4.9 × 10⁵ cfu 100 ml^???1 in 1996–2000 period. Following the opening treatment system, fecal coliform density decreased 2.1 × 10⁴ cfu 100 ml^???1 during 2001–2005. A continuous improvement can be sustained in the water quality if direct inflow of untreated wastewater is prevented.     

Use of Large‐Scale Acoustic Monitoring to Assess Anthropogenic Pressures on Orthoptera Communities

Biodiversity monitoring at large spatial and temporal scales is greatly needed in the context of global changes. Although insects are a species‐rich group and are important for ecosystem functioning, they have been largely neglected in conservation studies and policies, mainly due to technical and methodological constraints. Sound detection, a nondestructive method, is easily applied within a citizen‐science framework and could be an interesting solution for insect monitoring. However, it has not yet been tested at a large scale. We assessed the value of a citizen‐science program in which Orthoptera species (Tettigoniidae) were monitored acoustically along roads. We used Bayesian model‐averaging analyses to test whether we could detect widely known patterns of anthropogenic effects on insects, such as the negative effects of urbanization or intensive agriculture on Orthoptera populations and communities. We also examined site‐abundance correlations between years and estimated the biases in species detection to evaluate and improve the protocol. Urbanization and intensive agricultural landscapes negatively affected Orthoptera species richness, diversity, and abundance. This finding is consistent with results of previous studies of Orthoptera, vertebrates, carabids, and butterflies. The average mass of communities decreased as urbanization increased. The dispersal ability of communities increased as the percentage of agricultural land and, to a lesser extent, urban area increased. Despite changes in abundances over time, we found significant correlations between yearly abundances. We identified biases linked to the protocol (e.g., car speed or temperature) that can be accounted for ease in analyses. We argue that acoustic monitoring of Orthoptera along roads offers several advantages for assessing Orthoptera biodiversity at large spatial and temporal extents, particularly in a citizen science framework. El Uso de Monitoreos Acústicos a Gran Escala para Estudiar las Presiones Antropogénicas sobre Comunidades de Orthoptera     

Ergonomic assessment of airport shuttle driver tasks using an ergonomic analysis toolset

This study aimed to (a) evaluate strength requirements and lower back stresses during lifting and baggage handling tasks with the 3D Static Strength Prediction Program (3DSSPP) and (b) provide additional analyses using rapid entire body assessment (REBA) and the NASA task load index (TLX) to assess the risks associated with the tasks. Four healthy female shuttle drivers of good health aged between 55 and 60 years were observed and interviewed in an effort to determine the tasks required of their occupations. The results indicated that lifting bags and placing them in a shuttle were high risk for injury and possible changes should be further investigated. The study concluded there was a potential for injury associated with baggage storing and retrieval tasks of a shuttle driver.     

Interactions between energy consumption,international trade,and real income in Canada: An empirical investigation from a new version of the Solow growth model

This study investigates the empirical relationship between energy consumption, international trade, and real income in Canada which has an important role in global energy and trade. It employs bound tests to level relationships and conditional error correction models through ARDL specification to a new version of the Solow Growth model. Using annual data of the 1960–2010 period, results reveal a long-term relationship between energy consumption, international trade, and real income in Canada. It is also found that energy exporting activity is the determinant (driver) of energy consumption through the channel of real income and energy consumption is the determinant (driver) of exports through the channel of real income in the long term of the Canadian economy. Exports and energy use are the determinants (drivers) of real income in the long term of the Canadian economy; therefore, as conditional Granger causality tests suggest there is feedback relationship between energy consumption, international trade, and real income in the long term of the Canadian economy. The present study suggests that any energy conservation policies are likely to have negative influence on output and international trade in Canada.