Health risk associated with heavy metal contamination of vegetables grown in agricultural soil of Siran valley, Mansehra, Pakistan-a case study.

Monitoring of heavy metals in agricultural soils and the crops grown in them is essential to design mitigation strategies to reduce toxic heavy metals in diet and food chains. We determined chromium (Cr), arsenic (As), cadmium (Cd), and lead (Pb) concentrations in the soil-plant system from agricultural fields of Siran Valley, Mansehra, Pakistan, to assess their potential health risk. Although the concentrations of the heavy metals in soils were within the permissible limits for agricultural soils, heavy metal concentrations in many of the vegetables exceeded the recommended safe values. Among the six leafy vegetables tested, all had greater than safe limits for As, four also for Cr and two also for Cd. As level was greater than safe limits in all five fruit and flower vegetables, two had Cr, and one had Pb also at unsafe levels. Among the five tuber, bulb, and root vegetables, As was higher than safe limits in all and Cd in one. The transfer factor in all three categories of vegetables followed the descending order Cd > As > Cr > Pb. Daily intake of metals were within limit set by USEPA for all heavy metals except As. The health risk indices for Cr, As, Cd, and Pb indicated that values greater than 1 for As suggest that the vegetables studied here pose a risk of chronic arsenic poisoning, but other heavy metals do not pose such a risk. Our study reinforces the need for mitigation strategies to reduce unsafe levels of heavy metals in vegetables.

Chemically modified sugarcane bagasse-based biocomposites for efficient removal of acid red 1 dye: Kinetics, isotherms, thermodynamics, and desorption studies.

Novel eco-friendly and economically favourable chemically modified biosorbents and biosomposites from sugarcane bagasse (SB) has been investigated for the first time for efficient removal of Acid red 1 dye from wastewater. As fabricated biosorbents and biocomposites were characterized analytically. Batch adsorption experiments has been performed to optimize operating parameters and the determined optimum conditions are; pH: 2, dose: 0.05 g, contact time: between 60 and 75 min, initial dye concentration: 400 mg L-1, and temperature: 30 °C, at which maximum Acid red 1 dye removal capacities were found (within range of 143.4-205.1 mg g-1) by as-designed SB-derived chemically modified biosorbents and biocomposites. This high adsorption capacity was accompanied due to its large specific surface area (30.19 m2 g-1) and excessive functional active binding sites. In terms of the nature of adsorption process, kinetic and isothermal studies demonstrated that experimental data shows greater fitness with pseudo 2nd order and Langmuir model. Thermodynamics analysis revealed that the adsorption process is spontaneous, feasible, and exothermic in nature. Adsorption selective studies signifies that lower concentration of co-existing metallic ions were not interfered during the removal of Acid red 1 dye, which confirms that under optimized adsorption conditions the biosorbents and biocomposites exhibited greater affinity for dye molecules. The excessive quantity (82%) of loaded dye molecules within the adsorbents were extracted within the NaOH eluting media which predicts that as designed biocomposites could have capability of reusability. Hence, it is anticipated that this type of novel SB-derived biocomposites could be considered as greener potential candidate material for commercial scale dye removal applications from industrial wastewater.

Magnetic mesoporous bioactive glass for synergetic use in bone regeneration, hyperthermia treatment, and controlled drug delivery.

A combination of chemotherapy with hyperthermia can produce remarkable success in treating advanced cancers. For this purpose, magnetite (Fe3O4)-doped mesoporous bioactive glass nanoparticles (Fe3O4-MBG NPs) were synthesized by the sol-gel method. Fe3O4-MBG NPs were found to possess spherical morphology with a size of approximately 50 ± 10 nm and a uniform pore size of 9 nm. The surface area (309 m2 g-1) was sufficient for high drug loading capacity and mitomycin C (Mc), an anticancer drug, was entrapped in the Fe3O4-MBG NPs. A variable rate of drug release was observed at different pH values (6.4, 7.4 & 8.4) of the release media. No significant death of normal human fibroblast (NHFB) cells was observed during in vitro analysis and for Mc-Fe3O4-MBG NPs considerable inhibitory effects on the viability of cancer cells (MG-63) were observed. When Fe3O4-MBG NPs were immersed in simulated body fluid (SBF), hydroxycarbonate apatite (HCA) was formed, as confirmed by XRD and FTIR spectra. A negligible value of coercivity and zero remanence confirms that Fe3O4-MBG NPs are superparamagnetic. Fe3O4-MBG NPs showed a hyperthermia effect in an alternating magnetic field (AMF), and a rise of 11.5 °C in temperature during the first 6 min, making it suitable for hyperthermia applications. Fe3O4-MBG NPs expressed excellent biocompatibility and low cytotoxicity, therefore, they are a safe biomaterial for bone tissue regeneration, drug delivery, and hyperthermia treatment.

Correction: Magnetic mesoporous bioactive glass for synergetic use in bone regeneration, hyperthermia treatment, and controlled drug delivery.

[This corrects the article DOI: 10.1039/C9RA09349D.].