Abstract Climate changes effects, food security and self-sufficiency targets in densely populated countries like Bangladesh forced excessive human activities on vegetable farmland, and heavy metal contamination may result. An analysis of three toxic heavy metals, such as lead (Pb), cadmium (Cd), and chromium (Cr), was conducted to determine their source and associated health risks in vegetables, taking into account source pathways, fertilizers/pesticides and soil, using 12 sampling points at two different locations in two different Flam-Atomic Absorption Spectrometry (F-AAS) and Graphite Furnace-AAS (GF-AAS) modes. In soil and fertilizers/pesticides, the mean concentration of heavy metals declined in the same order of Cr > Pb > Cd. For vegetables, the mean concentration decreased in the order of Pb > Cr > Cd with some extra quantity of Pb compared with an allowable limit of World Health Organization (WHO) predicting industrial and fertilizer usage impact on location B. For both locations, the quality indexing of soil projected low levels of contamination with insignificant ecological risks. The toxic metal transfer to vegetables followed the order Cd > Pb > Cr, the same for both locations but higher at location B. However, the toxic metals uptake through vegetables was much less than maximum tolerable daily intake. The human health risks arising from harmful metals exposure at both locations were ineffective (< 1) in evaluating non-carcinogenic risk patterns through target hazard quotient (THQ), total THQ and hazard index (HI). Again considering probable carcinogenic risk patterns, vegetable consumption with studied exposure levels of toxic metals will be significant (between 1.0E-04 to 1.0E-04). Overall, location B is a little bit more vulnerable than A by considering the non-carcinogenic and carcinogenic model and related intervention and protective measures are needed to be taken.
Globally, both natural water bodies and aquaculture systems are being severely contaminated by heavy metals due to rising anthropogenic activities. Fish living in aquatic environments can easily accumulate metals in their bodies, which can then be transferred to consumers and put them at risk. In this study, metal concentrations (Pb, Cd, Cr, As, Mn, Cu, Zn) in different organs (gill, liver, and muscle) of farmed and wild Barramundi (Lates calcarifer) fish from the northern Bay of Bengal were evaluated to quantify and compare contamination levels and related human health risk. Heavy metal concentrations were higher in liver tissues of farmed Barramundi than in wild Barramundi, with the following relative mean values in the liver, gills, and muscle: Zn > Cu > Pb > Mn > Cd > Cr > As; Zn > Cr > Cu > Pb > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; and Zn > Pb > Cu > Cr > Mn > Cd > As, respectively. The differences in heavy metal accumulation observed between farmed and wild fish were probably related to the differences in their environmental conditions and dietary element concentrations. However, ANOVA indicated that the variation of metals in wild and Barramundi was not statically significant. Pb concentrations in the liver tissue of farmed Barramundi exceeded the national and international threshold limits, whereas concentrations of other metals were within the limit. Among the examined organs in both fish species (wild and farmed), muscle had the lowest concentration compared to others, and liver was the target organ for Pb, Cu, and Cd accumulations. Metals such as Zn and Mn exhibited higher concentration in the gills. However, all the studied heavy metals were below the maximum permissible limits of national and international standards, but the mean concentrations of Pb and Cd values in the liver of farmed Barramundi exceeded all international and national guidelines. Based on the contamination factors (CF) and pollution indices (PLI and MPI), the degree of contamination in the fish organs was as follows: gills > liver > muscle. The major accumulation tissues for both farmed and wild fish were found to be the gills (MPI = 0.970) and the liver (MPI = 0.692). Based on the estimated daily intake (EDI), the fish samples examined in this study are safe for human consumption as within the recommended daily allowance (RDA) range established by various authorities. According to the Target Hazard Quotient (THQ) and Carcinogenic Risk (CR) calculations, though the Barramundi fishes depicted no potential hazard to humans, farmed fish posed a higher health risk than wild fish.
Rivers, often the primary recipients of untreated domestic and industrial effluents, have increasingly become reservoirs of potent toxins, particularly heavy metals, raising serious concerns for the health of both human and aquatic life. This study investigates the ecological and human health risks associated with heavy metal accumulation in sediments and fish from the Padma River, a major river system in Bangladesh. Using Atomic Absorption Spectrometry (AA-7000 series), we analysed the concentrations of cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb) and zinc (Zn) across six major urban areas, revealing significant variability in metal accumulation among different stations. The highest levels of heavy metal accumulation were observed in the Chandpur and Pabna districts, with notably elevated concentrations of Cr, Cu, Hg, and Pb in both sediment and fish samples. Ecological risk assessments indicated 'heavy contamination' of Cr in sediments, highlighting the deficiencies in waste management systems in Bangladesh. Omnivorous and piscivorous species such as M. corsula, X. cancila, and M. armatus from the Chapainawabganj, Pabna, and Chandpur districts exhibited higher metal concentrations compared to other species. Health risk indices such as THQ and HI suggest a significant non-carcinogenic risk of Hg in Chapainawabganj and Chandpur. Additionally, a severe long-term cancer risk from dietary Cr exposure (TR: M. corsula = 4.26 × 10−2) can be experienced by the regular consumers of contaminated fish from the Padma River.
Abstract Bioactive compounds containing the four most common and often used powdered spices for food preparation have been studied concerning lead contamination and human health risk assessment, especially in branded and nonbranded categories. A total of 72 spice samples were analysed using Varian AA240FS flame atomic absorption spectrometry. A validated and optimized method using hot plate digestion was used for this study. Freshly prepared standards were used to construct a calibration curve. The overall range of lead levels in branded and nonbranded spice samples was found to be < 0.27–2.80, < 0.27–0.48, < 0.27–13.83, 0.28–8.19 and < 0.27–5.56, < 0.27–3.84, < 0.27–37.29, 0.29–0.65 for cumin powder, red pepper chili, turmeric powder, and coriander powder, respectively. The nonbranded item has shown slightly higher value than branded items except coriander powder. Approximately 90% of the spice samples were shown to be within the maximum allowable limit by the Bangladesh Standard. The studied Pb level was inconsistent in both categories of spices but did not have any health implications in the case of carcinogenic and noncarcinogenic studies. Overall, Pb concentrations in most common spices collected from Dhaka city were found to be slightly higher in nonbranded items. This shows us that it is of vital importance that the areas where spices are collected are clean, especially by means of Pb, because these spices can cause more benefits than harm they may provide in such a contamination.
This research evaluated pH-responsive release characteristics for the drug (ciprofloxacin hydrochloride) from micro-, nano-, and functionalized cellulose forms. Nanocrystalline cellulose (NCC) was prepared from microcrystalline cellulose (MCC) by sulfuric acid hydrolysis. The aldehyde (–CHO) groups were introduced at the carbon-2 (C-2) and carbon-3 (C-3) positions of glucose moiety of the cellulose network by selective oxidation to form di-aldehyde nanocellulose (DANC). The conversion was validated by chemical, spectroscopic, morphological, and crystallographic analysis. Drug binding capacity (mg/g) of DANC was higher (200.8 mg/g) compared to NCC (138.3 mg/g) and MCC (120.2 mg/g), respectively. The increase in pH from 2.5 to 8.5 enhanced drug release for all the excipients. At pH 2.5, slow release of the drugs was observed. In 6 h, DANC released 44.7 % of the loaded drug at pH 2.5. However, drug release reached equilibrium (84.8 % of loaded drug) within 10 min at pH 8.5. The release kinetics at acidic pH were validated using zero-order, first-order, Higuchi, and Korsmeyer-Peppas kinetics models. Higuchi and Korsmeyer–Peppas kinetic models simultaneously interpreted drug release phenomena very well. This implies that diffusion, dissolution, swelling, and slight erosion contribute to drug release. The results suggest that selective functionalization can be applied to cellulose for its potential applications in pH-responsive drug delivery, and therefore, the functionalized cellulose deserves immediate attention.
