Unraveling prevalence and public health risks of arsenic,uranium and co-occurring trace metals in groundwater along riverine ecosystem in Sindh and Punjab,Pakistan

Environmental Geochemistry and Health - The current study focuses on the understanding of contamination status, distribution, source apportionment and health perspectives of arsenic (As), uranium...     

Upgraded modified forms of bituminous coal for the removal of safranin-T dye from aqueous solution

Natural bituminous coal was used as a precursor in the synthesis of different modified products. The modification of coal was performed by treating it with nitric acid (N-coal), coating its surface by zinc oxide nanoparticles (Z-coal), and converting it into porous graphite (PG). The effect of modification processes on the structures, morphologies, and optical properties was followed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT-IR), and UV/VIS spectrophotometer analysis. The surface of N-coal grains becomes smoother than the surface of raw coal grains due to the removal of the associated impurities and the formation of nitrogen function groups. For Z-coal, the whole surface of coal grains appears to be completely covered by agglomerated ZnO nanoparticles of massive density and irregular shapes. The average crystallite size of the formed ZnO is ~22.2 nm and density of dislocations is 2.029 × 10^?3 dislocation/nm². Also, the removal of safranin-T dye by natural bituminous coal and its modified forms was investigated as a function of contact time, adsorbent mass, initial dye concentration, and pH value. At pH 8, the PG showed higher efficiency (96%) than Z-coal (93.5%), N-coal (74.5%), and natural coal (62%) after 2 h for 0.1 g on 100 mg/L dye. The obtained results are well fitted by pseudo-second-order kinetic than by intraparticle diffusion and Elovich kinetic models for the adsorption by N-coal, Z-coal, and PG, whereas the adsorption by raw coal is well fitted with both pseudo-second-order and Elovich kinetic models. The Langmuir isotherm model fits well the equilibrium adsorption isotherm of safranin by raw coal and its modified forms. The values of maximum adsorption capacity were calculated for raw coal, N-coal, Z-coal, and PG to be 21.3, 27.4, 32.46, and 33.67 mg/g, respectively. A monolayer model with one energy and a monolayer model with two energies as advanced equilibrium models were investigated for more physical interpretation of the adsorption process. The calculated parameters (number of adsorbed molecules per site and number of receptor sites per unit mass) reflected the role of modification processes in the adsorption behavior of safranin.

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Graphical abstract High volatile bituminous coal and its modified forms have been used for the removal of Safranin-T dye from aqueous solution.

     

Establishing influence of morphological aspects on microclimatic conditions through GIS-assisted mathematical modeling and field observations

Environment, Development and Sustainability - Local climate in an area is significantly affected by the extent of urbanization. The microclimatic parameters such as wind speed (W), relative...     

Effect of industrial by-products containing electron acceptors on mitigating methane emission during rice cultivation

Three industrial by-products (fly ash, phosphogypsum and blast furnace slag), were evaluated for their potential re-use as soil amendments to reduce methane (CH₄) emission resulting from rice cultivation. In laboratory incubations, CH₄ production rates from anoxic soil slurries were significantly reduced at amendment levels of 0.5%, 1%, 2% and 5% (wt wt⁻¹), while observed CO₂ production rates were enhanced. The level of suppression in methane production was the highest for phosphogypsum, followed by blast slag and then fly ash. In the greenhouse experiment, CH₄ emission rates from the rice planted potted soils significantly decreased with the increasing levels (2–20 Mg ha⁻¹) of the selected amendments applied, while rice yield simultaneously increased compared to the control treatment. At 10 Mg ha⁻¹ application level of the amendments, total seasonal CH₄ emissions were reduced by 20%, 27% and 25%, while rice grain yields were increased by 17%, 15% and 23% over the control with fly ash, phosphogypsum, and blast slag amendments, respectively. The suppression of CH₄ production rates as well as total seasonal CH₄ flux could be due to the increased concentrations of active iron, free iron, manganese oxides, and sulfate in the amended soil, which acted as electron acceptors and controlled methanogens’ activity by limiting substrates availability. Among the amendments, blast furnace slag and fly ash contributed mainly to improve the soil nutrients balance and increased the soil pH level towards neutral point, but soil acidity was developed with phosphogypsum application. Conclusively, blast slag among the selected amendments would be a suitable soil amendment for reducing CH₄ emissions as well as sustaining rice productivity.     

Comparison of several maturity indicators for estimating phytotoxicity in compost-amended soil

Compost can provide a rich organic nutrient source and soil conditioner for agricultural and horticultural applications. Ideal compost amendment rates, however, vary based on starting material and compost maturity or their interaction, and there is little consensus on appropriate methods to gauge maturity. In this study, electrical conductivity, carbon-to-nitrogen ratio, and carbon mineralization measurements were made on compost-amended soils and compared to phytotoxicity measured as cress (Lepidium sativum) germination. Cress germination in soil and compost mixtures incubated for 8-10 days significantly decreased with increasing electrical conductivity and carbon mineralization rate of the mixture and with carbon mineralization rate and mineralizable carbon associated with the compost. Cress germination was not related to carbon-to-nitrogen ratio or pH of soil and compost mixtures. The electrical conductivity of the soil and compost mixtures significantly decreased with decreasing mineralizable carbon suggesting that compounds contributing to electrical conductivity were present in the compost and decomposed upon soil amendment. The results of this study indicate that measurements of mineralizable carbon and mineralization rate of composts in soil, and electrical conductivity and mineralization rate of soil and compost mixtures, can be used as indicators of compost maturity.     

Air pollution and child health: the impact of brick kiln pollution on children's cognitive abilities and physical health in Pakistan

Environment, Development and Sustainability - This study explores the adverse impact of air pollution, caused by emissions from brick kilns, on the children’s cognitive ability and physical...     

Correlation of MSH2 exonic deletions and protein downregulation with breast cancer biomarkers and outcome in Pakistani women/patients

Environmental Science and Pollution Research - Mismatch repair (MMR) pathway is one of the underlying mechanisms of predisposition to breast cancer (BC). The present study explored the association...     

Perspectives of using fungi as bioresource for bioremediation of pesticides in the environment: a critical review

Pesticides are used for controlling the development of various pests in agricultural crops worldwide. Despite their agricultural benefits, pesticides are often considered a serious threat to the environment because of their persistent nature and the anomalies they create. Hence removal of such pesticides from the environment is a topic of interest for the researchers nowadays. During the recent years, use of biological resources to degrade or remove pesticides has emerged as a powerful tool for their in situ degradation and remediation. Fungi are among such bioresources that have been widely characterized and applied for biodegradation and bioremediation of pesticides. This review article presents the perspectives of using fungi for biodegradation and bioremediation of pesticides in liquid and soil media. This review clearly indicates that fungal isolates are an effective bioresource to degrade different pesticides including lindane, methamidophos, endosulfan, chlorpyrifos, atrazine, cypermethrin, dieldrin, methyl parathion, heptachlor, etc. However, rate of fungal degradation of pesticides depends on soil moisture content, nutrient availability, pH, temperature, oxygen level, etc. Fungal strains were found to harbor different processes including hydroxylation, demethylation, dechlorination, dioxygenation, esterification, dehydrochlorination, oxidation, etc during the biodegradation of different pesticides having varying functional groups. Moreover, the biodegradation of different pesticides was found to be mediated by involvement of different enzymes including laccase, hydrolase, peroxidase, esterase, dehydrogenase, manganese peroxidase, lignin peroxidase, etc. The recent advances in understanding the fungal biodegradation of pesticides focusing on the processes, pathways, genes/enzymes and factors affecting the biodegradation have also been presented in this review article.     

Screening of human health risk to infants associated with the polychlorinated biphenyl (PCB) levels in human milk from Punjab Province,Pakistan

This study assessed the polychlorinated biphenyl (PCB) levels in human milk and its associated health risk to infants from rural and urban settings of five districts of Punjab Province, Pakistan. The ∑₃₄PCB concentrations ranged from 30.9 to 68.3 ng g^?1 on lipid weight (l.w.) basis. The ∑₈DL-PCB concentrations were ranged from 0.29 to 1.35 ng g^?1 l.w., (mean 6.2 ± 8.7 ng g^?1 l.w.), with toxicity equivalent to polychlorinated dibenzodioxins (PCDDs) ranging from 8.58 × 10^?6 to 0.05 ng TEQ g^?1 l.w. The spatial trend of PCB levels in human milk revealed higher bioaccumulative levels for urban mothers as compared with rural counterparts. The estimated daily intake (EDI) values of DL-PCBs to infants through trans-mammary transfer were considerably higher than tolerable daily intake limits established by WHO (i.e., 1–4 pg TEQ kg^?1 bw) and other globally recognized organizations. Similarly, the hazard quotient values for TEQ ∑₈DL-PCBs (range 1.21 to 79.87) were far above the benchmark value of 1 at all the sampling sites, indicating the high levels of adverse health risks to infants in the region through breast milk consumption. The ∑₃₄PCB levels were found to be negatively correlated with mother’ age (r = ?0.31; p = 0.02), parity (r = ? 0.85; p = 0.001), and infant’ birth weight (r = ? 0.73; p = 0.01). The present study suggests undertaking comprehensive public health risk assessment studies and firm regulatory measures to safeguard human health risks.

     

Role of ambient air pollution in asthma spread among various population groups of Lahore City: a case study

Environmental Science and Pollution Research - Air pollution levels rise as a result of industrial and vehicular emissions, epidemiological issues such as asthma become more prevalent in Lahore,...