RESUMO
Thorough deliberation is necessary to safeguard the tropical urban streams near the shoreline from human interference, as it is becoming a notable environmental danger. Consequently, an in-depth study was carried out on a significant urban waterway located on the southern seashore of Bangladesh, which is positioned in the Bengal delta, renowned as the largest delta in the globe. The current investigation assesses the potential health hazards associated with trace metals (Hg, Cu, As, Pb, Ni, Zn, Cd, Cr, Fe, and Mn) and uses chemometric analysis to determine where they originate. Likewise geochemical methods are used to analyze the levels of trace metal enrichment and pollution in the sediments of the river. Almost all of the elements' mean concentrations were observed to be within the standard limits. The findings not only demonstrate the extent of trace metal contamination but also the health threats that it poses to the public (male, female, and children) by polluting the sediment. For all age groups of people, the hazard index was <1, suggesting there was no non-carcinogenic threat. Regardless of age and sex, exposure occurred in descending order: ingestion > dermal > inhalation. Total carcinogenic risk (TCR) values for males, females, and children were 1.45E-05, 1.56E-05, and 1.34E-04, respectively, recommending that children are at greater vulnerability than adults. The geochemical approach and chemometric analysis corroborate the human-induced impact of trace metal loading in the sediment of the waterway, which is predominantly caused by the oil industry, domestic garbage, and untreated waste discharge.
Assuntos
Monitoramento Ambiental , Metais , Poluentes Químicos da Água , Humanos , Medição de Risco , Poluentes Químicos da Água/análise , Bangladesh , Metais/análise , Feminino , Masculino , Sedimentos Geológicos/química , Criança , Metais Pesados/análiseRESUMO
Lanthanide-based, spectrally shifting, and multi-color luminescent upconverting nanoparticles (UCNPs) have received much attention in the last decades because of their applicability as reporter for bioimaging, super-resolution microscopy, and sensing as well as barcoding and anti-counterfeiting tags. A prerequisite for the broad application of UCNPs in areas such as sensing and encoding are simple, robust, and easily upscalable synthesis protocols that yield large quantities of UCNPs with sizes of 20 nm or more with precisely controlled and tunable physicochemical properties from low-cost reagents with a high reproducibility. In this context, we studied the reproducibility, robustness, and upscalability of the synthesis of ß-NaYF4:Yb, Er UCNPs via thermal decomposition. Reaction parameters included solvent, precursor chemical compositions, ratio, and concentration. The resulting UCNPs were then examined regarding their application-relevant physicochemical properties such as size, size distribution, morphology, crystal phase, chemical composition, and photoluminescence. Based on these screening studies, we propose a small volume and high-concentration synthesis approach that can provide UCNPs with different, yet controlled size, an excellent phase purity and tunable morphology in batch sizes of up to at least 5 g which are well suited for the fabrication of sensors, printable barcodes or authentication and recycling tags.
RESUMO
Despite the beneficial aspect of a natural drainage system, increasing human-induced activities, which include urbanization and growth in industrialization, degrade the ecosystem in terms of trace metal contamination. In response, given the great importance of the south-eastern drainage system in Bangladesh, a detailed evaluation of the human health risk as well as the potential ecological risk of trace metals (Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Se, V, Zn, and As) in Karnaphuli riverbed sediment was conducted. Mean levels of the elements in mg/kg were As (5.62 ± 1.47); Se (0.84 ± 0.61); Hg (0.37 ± 0.23); Be (1.17 ± 0.49); Pb (15.62 ± 8.42); Cd (0.24 ± 0.33); Co (11.59 ± 4.49); Cr (112.75 ± 40.09); Cu (192.67 ± 49.71); V (27.49 ± 10.95); Zn (366.83 ± 62.82); Ni (75.83 ± 25.87). Pollution indicators, specifically contamination factor (CF), pollution load index (PLI), degree of contamination (Cd), enrichment factor (EF), geo-accumulation index (Igeo), and potential ecological risk index (RI), were computed to assess sediment quality. For the first observation of health risk, chronic daily intake (CDI), hazard quotient (HQ), hazard index (HI), carcinogenic risk (CR) and total carcinogenic risk (TCR) indices were calculated. According to the results, CDI values through the ingestion route of both the adult and child groups were organized in the following descending mode respectively: Zn > Cu > Cr > Ni > V > Pb > Co > As > Se > Be > Cd > Hg. The non-carcinogenic risks were generally low for all routes of exposure, except HQingestion was slightly higher for both adults and children. The calculated hazard index (HI) was, nevertheless, within the permitted range (HI < 1). Similarly, none of the metals exhibited any carcinogenic risks, as all CR values were within the 10-4-10-6 range. The need for authoritative efforts and water policy for the sake of the surrounding ecosystem and human health in the vicinity of the examined watershed is strongly felt as an outcome of this study. The purpose of this study is to protect public health by identifying trace metal sources and reducing industrial and domestic discharge into this natural drainage system.
RESUMO
Hilsa shad (Tenualosa ilisha, Hamilton, 1822), the highly coveted table fish within the Indian subcontinent, is Bangladesh's most significant single-species fishery. To assess the risk that toxic metals pose to human health, certain health risk indices-estimated daily intake (EDI), target hazard quotient (THQ), total target hazard quotient (TTHQ), and target cancer risk (TR)-were calculated. The hierarchy of toxic metals (µg/g-ww) in Hilsa shad of the bay showed as Zn (13.64 ± 2.18) > Fe (9.25 ± 1.47) > Mn (2.98 ± 0.75) > Cu (0.57 ± 0.18) > Cr (0.23 ± 0.06) > Pb (0.22 ± 0.04) > As (0.08 ± 0.02) > Ni (0.06 ± 0.02) > Co (0.04 ± 0.01) > Cd (0.01 ± 0.003) in the wet season and Zn (11.45 ± 1.97) > Fe (10.51 ± 1.38) > Mn (3.80 ± 0.75) > Cu (0.73 ± 0.17) > Pb (0.30 ± 0.03) > Cr (0.20 ± 0.05) > As (0.09 ± 0.01) > Ni (0.08 ± 0.02) > Co (0.07 ± 0.02) > Cd (0.02 ± 0.004) in the dry season. The EDI of all the examined trace metals indicated no risk to human health from consuming Hilsa fish. The estimation of THQ and TTHQ suggested that the ingestion of both individual and combined trace metals through Hilsa shad consumption was safe from the perspective of human health. Also, there was no evidence of carcinogenic risk for consumers based on the evaluation of the TR value of metals (As, Pb, Cd, and Ni) due to Hilsa shad consumption.
Assuntos
Metais Pesados , Oligoelementos , Animais , Humanos , Cádmio , Bangladesh , Chumbo , Mianmar , Peixes , Índia , Metais Pesados/análise , Medição de Risco , Monitoramento AmbientalRESUMO
The VERsatile DIffractometer will set a new standard for a world-class magnetic diffractometer with versatility for both powder and single crystal samples and capability for wide-angle polarization analysis. The instrument will utilize a large single-frame bandwidth and will offer high-resolution at low momentum transfers and excellent signal-to-noise ratio. A horizontal elliptical mirror concept with interchangeable guide pieces will provide high flexibility in beam divergence to allow for a high-resolution powder mode, a high-intensity single crystal mode, and a polarized beam option. A major science focus will be quantum materials that exhibit emergent properties arising from collective effects in condensed matter. The unique use of polarized neutrons to isolate the magnetic signature will provide optimal experimental input to state-of-the-art modeling approaches to access detailed insight into local magnetic ordering.