With the population growth, urbanization and industrialization, China has become a hotspot of atmospheric deposition nitrogen (ADN), which is a threat to ecosystem and food safety. However, the impacts of increased ADN on rice growth and grain metal content are little studied. Based on previous long-term ADN studies, greenhouse experiment was conducted with four simulated ADN rates of 0, 30, 60 and 90 kg N ha-1 yr-1 (CK, N1, N2 and N3 as δ15N, respectively) to assess rice growth and metal uptake in a red soil ecosystem of southeast China during 2016-2017. Results showed that simulated ADN could promote rice growth and increase yields by 15.68-24.41% (except N2) and accumulations of cadmium (Cd) or copper (Cu) in organs. However, there was no linear relationship between ADN rate and rice growth or Cd or Cu uptake. The 15N-ADN was mainly accumulated in roots (21.31-67.86%) and grains (25.26-49.35%), while Cd and Cu were primarily accumulated in roots (78.86-93.44% and 90.00-96.24%, respectively). 15N-ADN and Cd accumulations in roots were significantly different between the two growing seasons (p
This study aimed to assess the concentrations and health effect of trace metals [cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)] on the road dust of selected locations in the city of Kuala Lumpur. Sampling was conducted thrice at four locations, namely, Tun Razak Road, Raja Abdullah Road, Tunku Abdul Rahman (TAR) Road, and Ayer Molek Road. The concentrations of trace metals in road dust were analyzed by inductively coupled plasma mass spectrometry. TAR Road presented the highest Cd, Cu, Ni, and Pb contents compared with the other roads. The pollution level of trace metals in road dust was assessed by pollution index and pollution load index (PLI), showing that all studied locations were highly contaminated except Ayer Molek Road. Based on the PLI value, the sequence of pollution in descending order is as follows: TAR Road > Raja Abdullah Road > Tun Razak Road > Ayer Molek Road. Health risk assessment was performed to assess the health effects of carcinogenic and noncarcinogenic pollutants caused by the exposure to trace metals in road dust on adults and children. Based on the integrated hazard index values for children at all locations, >1 indicates a possible noncarcinogenic effect. All incremental lifetime cancer risk values for adult and children at all locations are within acceptable limits and are considered safe.
Traditionally, in Chinese medicine, tree peony and apple flower buds are used to prepare herbal decoctions to cure various ailments. As both of these flowers are popular and used regularly, providing scientific evidence on their basic composition is a necessity. Hence, in the present study, we report the chemical composition of these two flower buds. Results revealed tree peony and apple flower buds to have high crude protein (15.73 and 26.30%), fibre (13.11 and 16.51%), and carbohydrate (57.84 and 40.63%) contents. Both the flowers had significant amounts of essential amino acids and unsaturated fatty acids. Essential minerals present in tree peony and apple flowers were potassium (1540.37 and 1125.60 mg/100 g), calcium (462.46 and 449.98 mg/100 g), magnesium (241.51 and 164.23 mg/100 g), sodium (12.75 and 20.06 mg/100 g), and phosphorus (420.00 and 590.00 mg/100 g), respectively. Heavy metals (cadmium, nickel, mercury, lead, and arsenic) were detected in trace amounts (< 0.50 mg/100 g) in both the flower buds. Results obtained indicate that both flowers could be exploited as an additional source of nutraceutical for the development of new functional foods.
A comprehensive study of the chemical composition of rainwater was carried out from October 2016 to September 2017 in the equatorial tropical rainforest region of northwestern Borneo. Monthly cumulative rainwater samples were collected from different locations in the Limbang River Basin (LRB) and were later categorized into seasonal samples representing northeast monsoon (NEM), southwest monsoon (SWM), and inter-monsoon (IM) periods. Physical parameters (pH, EC, TDS, DO, and turbidity), major ions (HCO3-, Cl-, Ca2+, Mg2+, Na+, and K+) and trace metals (Co, Ni, Cd, Fe, Mn, Pb, Zn, and Cu) were analyzed from collected rainwater samples. Rainwater is slightly alkaline with mean pH higher than 5.8. Chloride and bicarbonate are the most abundant ions, and the concentration of major ions in seasonal rainwater has shown slight variation which follows a descending order of HCO3-> Cl-> Na+ > Ca2+ > Mg2+ > K+ in NEM and Cl- > HCO3- > Na+ > Ca2+ > K+ > Mg2+ in SWM and Cl- > HCO3- > Na+ > Ca2+ > Mg2+ > K+ in IM period. Trace metals such as Fe and Ni have shown dominance in seasonal rainwater samples, and all the metals have shown variation in concentration in different seasons. Variation in chemical characteristic of seasonal rainwater samples identified through piper diagram indicates dominance of Ca2+-Mg2+-HCO3- and mixed Ca2+-Mg2+-Cl- facies during NEM, SWM, and IM periods. Statistical analysis of the results through two-way ANOVA and Pearson's correlation also indicates significant variation in physico-chemical characteristics. This suggests a variation in contributing sources during the monsoon seasons. Factor analysis confirmed the source variation by explaining the total variance of 79.80%, 90.72%, and 90.52% with three factor components in NEM, SWM, and IM rainwater samples with different loading of parameters. Enrichment factor analysis revealed a combined contribution of marine and crustal sources except K+ which was solely from crustal sources. Sample analysis of backward air mass trajectory supports all these findings by explaining seasonal variation in the source of pollutants reaching the study area. Overall, the results show that the chemical composition of seasonal rainwater samples in LRB was significantly influenced by natural as well as anthropogenic processes. These include (long-range and local) industrial activities, fossil fuel combustion, forest burning, transportation activities including road transport and shipping activities, and land-derived soil dust along with chemical constituents carried by seasonal wind.
Cadmium chloride (CdCl2 ) has been reported to cause reproductive toxicity in male rats, mainly through oxidative stress. This study examined its effect on sexual behaviour, as one of the mechanisms of reproductive dysfunction, as well as the possible ameliorative effect of quercetin (QE) on same. Thirty male Wistar rats (10 weeks old), weighing 270-300 g, were used for this study. They were either orally administered 2% DMSO, CdCl2 (5 mg/kg b.w.), QE (20 mg/kg b.w.) or CdCl2 +QE, once daily for 4 weeks, before sexual behavioural studies. The 5th group received CdCl2 for 4 weeks and allowed 4-week recovery period, before sexual behavioural test. Rats were sacrificed after sexual behavioural studies. The blood, testis and penis were collected for biochemical assays. Cadmium increased mount, intromission and ejaculatory latencies, but reduced their frequencies, compared to control. Serum nitric oxide increased, while penile cyclic guanosine monophosphate reduced in the CdCl2 -exposed rats, compared to control. CdCl2 increased testicular cholesterol, but reduced 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-HSD activities, and testosterone concentration. QE better attenuated these negative changes compared to withdrawal of CdCl2 treatment. In conclusion, CdCl2 suppressed steroidogenesis, penile erection and sexual behaviour, with poor reversal following withdrawal, while QE attenuated these effects.
In this study, three popular, regionally grown rice varieties (Bario, brown and white) were compared with three of the most popular and highly marketed imported rice varieties (black, glutinous and basmati rice) in Penang region of Malaysia. Rice samples were evaluated for amino acids, fatty acids, minerals, heavy metals and dietary fiber composition. Overall, amino acids content among all the rice samples were comparable to each other. Results with regard to minerals showed potassium to be high in brown rice (197.41 mg/100g), while magnesium was recorded to be high in black rice (107.21 mg/100g). Heavy metals such as cadmium, nickel, mercury and lead, though present, they were in negligible amounts. Among all the rice varieties investigated, the total saturated fatty acid and unsaturated fatty acid content was highest in black rice (5.89%). The soluble dietary fiber was higher in white rice (16.39%), whereas insoluble dietary fiber was high in brown (16.51%) and black rice (14.49%), respectively. Results generated from this study is anticipated to benefit both the health wary consumers (based on their potential nutritional attributes) as well as the local food industries to choose the best rice variety while developing novel rice based food products.
To assess stress level induced by multiple stressors in aquatic organism, biomarkers have been adopted as early warning indicator due to their high accuracy, rapidity, and sensitivity. We investigated the effects of ectoparasitic isopod infection on heavy metal bioaccumulation (Fe, Cu, Zn, and Cd) in the fish Nemipterus furcosus and profiled the expression of metallothionein (MT) and heat shock proteins 70 (HSP70) genes of the fish host. Sixty individuals (parasitized and nonparasitized with Cymothoa truncata) were collected from three sites differing in the levels of anthropogenic activities off the South China Sea. Our results revealed no significant difference in heavy metal concentrations between infected and nonparasitized fish. We observed a positive correlation between heavy metal bioaccumulation in the fish host and anthropogenic activities. Accordingly, expression analysis of MT genes in fish liver showed significant differences in expression level between sampling sites, with lowest level in the least exploited site (Batu Rakit). A reverse pattern in HSP70 gene expression was demonstrated in fish muscle, showing the highest expression at Batu Rakit. While cymothoid infection in N. furcosus had no significant impact on fish MT gene expression, it resulted in a reduction of HSP70 level in liver of parasitized fish. These findings highlight the putative roles of MT in heavy metal assessment. Future studies should determine the kinetics of cymothoid infection and other potential stressors in characterizing the HSP70 gene expression profile.
In this study, pyrolysis technique was utilized for converting palm oil sludge to value added materials: bio-oil (liquid fuel) and bio-char (soil amendment). The bio-oil yield obtained was 27.4±1.7 wt.% having a heating value of 22.2±3.7 MJ/kg and a negligible ash content of 0.23±0.01 wt.%. The pH of bio-oil was in alkaline region. The bio-char yielded 49.9±0.3 wt.%, which was further investigated for sorption efficiency by adsorbing metal (Cd(2+) ions) from water. The removal efficiency of Cd(2+) was 89.4±2%, which was almost similar to the removal efficiency of a commercial activated carbon. The adsorption isotherm was well described by Langmuir model. Therefore, pyrolysis is proved as an efficient tool for palm oil sludge management, where the waste was converted into valuable products.
Metallic contamination in seafood, especially fish, has been of increasing concern to human health. Moreover, with increasing dependency on farmed fish for fish resources, the metallic contamination in them is still questionable. This study aimed to investigate the effects of cooking (steaming) on heavy metal concentration in farmed fish and to estimate its potential human health risk. Farmed sea basses (Lates calcarifer) from Setiu Lagoon were used to study the difference in metal uptake through human consumption of raw and cooked (steamed) fish samples. Selected heavy metals, namely copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb), were measured using ICP-MS following Teflon bomb closed digestion of the fish samples. Cooking of the fish muscle by steaming was applied to investigate if cooking changes the concentration of heavy metals. Mercury and As were found accumulated more notably in the fish muscle, though only Hg was found to show significant (p > 0.05) increase when L. calcarifer is cooked. The amount of As in the fish muscle throughout its growth can be potentially harmful to humans, with the highest averaged concentration at 3.29 ± 0.65 mg/kg dw. above the standard set by the Malaysian Food Regulation (1985) of >1 mg/kg. All the other heavy metals were at relatively safe concentrations well below the standard set by both national and international guidelines. The PTWI per individual of L. calcarifer for As was at 0.84 mg/kg bw., which indicated that the amount of this fish safe for consumption without any adverse effect is 170 g/week. Therefore, long-term intake of these fish may pose a risk to human health due to the relatively higher Hg and As concentration found in these fishes.
The accumulation of potentially toxic elements (PTEs) has raised public awareness due to harmful contamination to both human and marine creatures. This study was designed to determine the concentration of copper (Cu), zinc (Zn), cadmium (Cd), and nickel (Ni) in the intestine, kidney, muscle, gill, and liver tissues of local commercial edible fish, fourfinger threadfin (Eleutheronema tetradactylum), and black pomfret (Parastromateus niger) collected from Morib (M) and Kuala Selangor (KS). Among the studied PTEs, Cu and Zn were essential elements to regulate body metabolism with certain dosages required while Cd and Ni were considered as non-essential elements that posed chronic and carcinogenic risk. The concentration of PTEs in fish tissue samples was analyzed using flame atomic absorption spectrometry (F-AAS). By comparing the concentration of PTEs in fish tissues as a bioindicator, the environmental risk of Morib was more serious than Kuala Selangor because both fish species collected from Morib resulted in a higher PTEs concentration. For an average 62 kg adult with a fish ingestion rate (FIR) of 0.16 kg/person/day in Malaysia, the estimated weekly intake (EWI) of Cd from the consumption of E. tetradactylum (M: 0.0135 mg/kg; KS: 0.0134 mg/kg) and P. niger (M: 0.0140 mg/kg; KS: 0.0132 mg/kg) had exceeded the provisional tolerable weekly intake (Cd: 0.007 mg/kg) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and oral reference dose (ORD) values of Cd (0.001 mg/kg/day) as provided by the United States Environmental Protection Agency (USEPA) regional screening level, thus it posed chronic risks for daily basis consumption. Besides, the value of the carcinogenic risk of Cd (0.7-3 to 0.8-3) and Ni (0.5-3 to 0.6-3) were in between the acceptable range (10-6 to 10-4) of the health index that indicates a relatively low possibility cancer occurrence to the consumers in both Morib and Kuala Selangor. This study recommended FIR to be 0.80 kg/person/day to reduce the possibility of posing chronic and carcinogenic risks while at the same time obtaining the essential nutrients from the fish.
This study was conducted to determine the effects of rice husk ash (RHA) and Fe-coated rice husk ash (Fe-RHA) on the bioavailability and mobility of As, Cd, and Mn in mine tailings. The amendments were added to the tailings at 0, 5, 10, or 20% (w/w) and the mixtures were incubated for 0, 7, 15, 30, 45, and 60 days. The CaCl2 extractable As, Cd, and Mn in the amended tailings were determined at each interval of incubation period. In addition, the tailings mixture was leached with simulated rain water (SRW) every week from 0 day (D 0) until day 60 (D 60). The results showed that both RHA and Fe-RHA application significantly decreased the CaCl2-extractable Cd and Mn but increased that of As in the tailings throughout the incubation period. Consequently, addition of both RHA and Fe-RHA leached out higher amount of As from the tailings but decreased Cd and Mn concentration compared to the controls. The amount of As leached from the Fe-RHA-amended tailings was less than that from RHA-amended tailings. Application of both RHA and Fe-RHA could be an effective way in decreasing the availability of cationic heavy metals (Cd and Mn) in the tailings but these amendments could result in increasing the availability of anionic metalloid (As). Therefore, selection of organic amendments to remediate metal-contaminated tailings must be done with great care because the outcomes might be different among the elements.
The title compound, [Cd2(C8H8NS2)4], is a centrosymmetric dimer with both chelating and μ2-tridentate di-thio-carbamate ligands. The resulting S5 donor set defines a Cd(II) coordination geometry inter-mediate between square-pyramidal and trigonal-bipyramidal, but tending towards the former. The packing features C-H⋯S and C-H⋯π inter-actions, which generate a three-dimensional network. The influence of these inter-actions, along with intra-dimer π-π inter-actions between chelate rings, has been investigated by an analysis of the Hirshfeld surface.
In this study, the Cu(II) and Cd(II) ions removal behavior of crosslinked chitosan beads grafted poly(methacrylamide) (abbreviated as crosslinked chitosan-g-PMAm) from single metal ion solutions was investigated. The modified chitosan beads presented a remarkable improvement in acid resistance. The batch experiments demonstrated that pH of solution played a significant role in adsorption. It was found that the adsorption of Cu(II) and Cd(II) were optimum at pH 4 and pH 5, respectively. The maximum adsorption capacities for Cu(II) and Cd(II) based on Langmuir equation were 140.9 mg g-1 and 178.6 mg g-1, respectively. Pseudo-second order gave a better fit for adsorption data with respect to linearity coefficients than pseudo-first order suggesting that chemisorption or electron transfer is the dominant mechanism of the metal ions onto crosslinked chitosan-g-PMAm. In addition, X-ray photoelectron spectroscopy (XPS) investigations revealed that adsorption of both metal ions took place on the surfaces of crosslinked chitosan-g-PMAm by chelation through CNH2, CO and CO groups. Overall, the modified chitosan has proved a promising adsorbent for removal of metal ions.
In the current scenario, many synthetic chemicals have used long-term to control pests and mosquitoes, leading to the resistance of strains and toxicity effect on human beings. To overcome the adverse problem in recent advances, the scientific community is looking into nanofabricated pesticides and mosquitoes. This study aims to synthesize the recyclable chitosan-coated cadmium nanoparticles (Ch-CdNps) using Plumeria alba flower extract, which was further applied for insecticidal and mosquitocidal activities. The synthesized Ch-CdNps were confirmed by UV spectroscopy and FTIR analysis. The XRD, TEM, and DLS results confirmed the crystallinity with a spherical shape at 80-100 nm. The insecticidal activity proves that Ch-CdNps inhibited Helicoverpa armigera and Spodoptera litura at 100 ppm. In mosquitocidal, LC50 values of larvicidal of 1st instar were 4.116, 4.33, and 4.564 µg/mL, and the remaining three stages of instars, pupicidal, adulticidal, longevity, fecundity, and ovicidal assays inhibit the Anopheles stephensi followed by Aedes aegypti and Culex quinquefasciatus. Further, the first-order kinetics of photocatalytic degradation of methylene blue and methyl orange was confirmed. Based on the obtained results, Ch-CdNps can inhibit the pest, mosquitoes, and photocatalytic degradation.
Eukaryotic cells typically respond to stress conditions by inhibiting global protein synthesis. The initiation phase is the main target of regulation and represents a key control point for eukaryotic gene expression. In Saccharomyces cerevisiae and mammalian cells this is achieved by phosphorylation of eukaryotic initiation factor 2 (eIF2α). We have examined how the fungal pathogen Candida albicans responds to oxidative stress conditions and show that oxidants including hydrogen peroxide, the heavy metal cadmium and the thiol oxidant diamide inhibit translation initiation. The inhibition in response to hydrogen peroxide and cadmium largely depends on phosphorylation of eIF2α since minimal inhibition is observed in a gcn2 mutant. In contrast, translation initiation is inhibited in a Gcn2-independent manner in response to diamide. Our data indicate that all three oxidants inhibit growth of C. albicans in a dose-dependent manner, however, loss of GCN2 does not improve growth in the presence of hydrogen peroxide or cadmium. Examination of translational activity indicates that these oxidants inhibit translation at a post-initiation phase which may account for the growth inhibition in a gcn2 mutant. As well as inhibiting global translation initiation, phosphorylation of eIF2α also enhances expression of the GCN4 mRNA in yeast via a well-known translational control mechanism. We show that C. albicans GCN4 is similarly induced in response to oxidative stress conditions and Gcn4 is specifically required for hydrogen peroxide tolerance. Thus, the response of C. albicans to oxidative stress is mediated by oxidant-specific regulation of translation initiation and we discuss our findings in comparison to other eukaryotes including the yeast S. cerevisiae.
This research was to determine nutritional composition, essential and toxic elemental content, and major phenolic acid with antioxidant activity in Kadsura coccinea fruit. The results indicated that Kadsura coccinea fruit exhibited the high contents of total protein, total fat, ash and essential elements such as calcium (Ca), ferrum (Fe) and phosphorus (P). The levels of four common toxic elements, i.e. cadmium (Cd), mercury (Hg), arsenic (As) and lead (Pb), were lower than legal limits. By high-performance liquid chromatography (HPLC) analysis, gallic acid was identified as major phenolic acid in peel and pulp tissues. Its contents were no significant difference in both tissues. In comparison with two commercial antioxidants, the major phenolic acid extracted from Kadsura coccinea exhibited stronger 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity and reducing power. Kadsura coccinea fruit is a good source of nutrition and natural antioxidant. It is worthwhile to popularize this exotic fruit around the world.
Currently, nano-formulated mosquito larvicides have been widely proposed to control young instars of malaria vector populations. However, the fate of nanoparticles in the aquatic environment is scarcely known, with special reference to the impact of nanoparticles on enzymatic activity of non-target aquatic invertebrates. In this study, we synthesized CdS nanoparticles using a green protocol relying on the cheap extract of Valoniopsis pachynema algae. CdS nanoparticles showed high toxicity on young instars of the malaria vectors Anopheles stephensi and A. sundaicus. The antimalarial activity of the nano-synthesized product against chloroquine-resistant (CQ-r) Plasmodium falciparum parasites was investigated. From a non-target perspective, we focused on the impact of this novel nano-pesticide on antioxidant enzymes acetylcholinesterase (AChE) and glutathione S-transferase (GST) activities of the mud crab Scylla serrata. The characterization of nanomaterials was carried out by UV-vis and FTIR spectroscopy, as well as SEM and XRD analyses. In mosquitocidal assays, LC50 of V. pachynema-synthesized CdS nanoparticles on A. stephensi ranged from 16.856 (larva I), to 30.301μg/ml (pupa), while for An. sundaicus they ranged from 13.584 to 22.496μg/ml. The antiplasmodial activity of V. pachynema extract and CdS nanoparticles was evaluated against CQ-r and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. IC50 of V. pachynema extract was 58.1μg/ml (CQ-s) and 71.46μg/ml (CQ-r), while nano-CdS IC50 was 76.14μg/ml (CQ-s) and 89.21μg/ml (CQ-r). In enzymatic assays, S. serrata crabs were exposed to sub-lethal concentrations, i.e. 4, 6 and 8μg/ml of CdS nanoparticles, assessing changes in GST and AChE activity after 16days. We observed significantly higher activity of GST, if compared to the control, during the whole experiment period. In addition, a single treatment with CdS nanoparticles led to a significant decrease in AChE activity over time. The toxicity of CdS nanoparticles and Cd ions in aqueous solution was also assessed in mud crabs, showing higher toxicity of aqueous Cd ions if compared to nano-CdS. Overall, our results underlined the efficacy of green-synthesized CdS nanoparticles in malaria vector control, outlining also significant impacts on the enzymatic activity of non-target aquatic organisms, with special reference to mud crabs.
ZnS and CdS nanoparticles were prepared by a simple microwave irradiation method under mild conditions. The obtained nanoparticles were characterized by XRD, TEM and EDX. The results indicated that high purity of nanosized ZnS and CdS was successfully obtained with cubic and hexagonal crystalline structures, respectively. The band gap energies of ZnS and CdS nanoparticles were estimated using UV-visible absorption spectra to be about 4.22 and 2.64 eV, respectively. Photocatalytic degradation of methylene blue was carried out using physical mixtures of ZnS and CdS nanoparticles under a 500-W halogen lamp of visible light irradiation. The residual concentration of methylene blue solution was monitored using UV-visible absorption spectrometry. From the study of the variation in composition of ZnS:CdS, a composition of 1:4 (by weight) was found to be very efficient for degradation of methylene blue. In this case the degradation efficiency of the photocatalyst nanoparticles after 6 h irradiation time was about 73% with a reaction rate of 3.61 × 10-3 min-1. Higher degradation efficiency and reaction rate were achieved by increasing the amount of photocatalyst and initial pH of the solution.
Honey is a popular natural food product with a very complex composition mainly consisting of both organic and inorganic constituents. The composition of honey is strongly influenced by both natural and anthropogenic factors, which vary based on its botanical and geographical origins. Although minerals and heavy metals are minor constituents of honey, they play vital role in determining its quality. There are several different analytical methods used to determine the chemical elements in honey. These methods are typically based on spectroscopy or spectrometry techniques (including atomic absorption spectrometry, atomic emission spectrometry, inductively coupled plasma mass spectrometry, and inductively coupled plasma optical emission spectrometry). This review compiles available scientific information on minerals and heavy metals in honey reported from all over the world. To date, 54 chemical elements in various types of honey have been identified and can be divided into 3 groups: major or macroelements (Na, K, Ca, Mg, P, S, Cl), minor or trace elements (Al, Cu, Pb, Zn, Mn, Cd, Tl, Co, Ni, Rb, Ba, Be, Bi, U, V, Fe, Pt, Pd, Te, Hf, Mo, Sn, Sb, La, I, Sm, Tb, Dy, Sd, Th, Pr, Nd, Tm, Yb, Lu, Gd, Ho, Er, Ce, Cr, As, B, Br, Cd, Hg, Se, Sr), and heavy metals (trace elements that have a specific gravity at least 5 times higher than that of water and inorganic sources). Chemical elements in honey samples throughout the world vary in terms of concentrations and are also influenced by environmental pollution.