Assessment of heavy metals in raw food samples from open markets in two African cities

Influence of geographical location on the distribution of heavy metals in dairy cattle feeds sourced from two South African provinces

The contamination of feed and food by heavy metals represents a significant concern for the health of both animals and humans. This study investigates the impact of geographical location on heavy metal distribution in dairy cattle feeds sourced from Free State and Limpopo, South Africa (SA). A total of 70 feed samples (40 from Free State and 30 from Limpopo) were collected from 2018 to 2019 and analyzed for heavy metals, including cadmium (Cd), arsenic (As), copper (Cu), zinc (Zn), lead (Pb), and chromium (Cr), using inductively coupled plasma mass spectrometry (ICP-MS). Our findings revealed the presence of Cr, Cu, and Zn in the feeds, but at levels below the FAO/WHO permissible limits. Additionally, As, Cd, and Pb concentrations in the feeds were below the Limit of Detections (LODs). Generally, Cr concentrations (0.032-0.454 mg/kg) identified in the Free State samples were lower than those found in Limpopo (0.038-1.459 mg/kg), while the levels of Cu (0.092-4.898 mg/kg) and Zn (0.39-13.871 mg/kg) recorded in the Free State samples were higher than those from Limpopo [(0.126-3.467 mg/kg) and (0.244-13.767 mg/kg), respectively]. According to independent sample t-tests, Cu and Zn levels were substantially higher (p ≤ .05) in Free State feeds compared to Limpopo, while Limpopo feeds exhibited significantly higher (p ≤ .05) Cr concentrations than Free State feeds. Despite the low recorded heavy metal levels, regular monitoring of these elements in cow diets across all SA provinces is essential for ensuring the well-being of animals and humans.

Influence of Different Rates of Plant-Based Compost on Clay Soil Metal Behavior and Human Health Risk Assessment in Moringa oleifera Leaf Biomass

An investigation of the impact of adding plant-based organic compost to clay soil from a Moringa oleifera farm focusing on the metal content, bioavailability, and accumulation of nutrients in M. oleifera leaves was conducted. Clay soil was mixed with 15%, 30%, 45% and 60% plant-based organic compost (by volume) in 20 cm wide, 2 L pots. Moringa oleifera plants were planted in four replicates of each treatment and control group. Results revealed that the addition of compost significantly (P < 0.05) altered the concentration of metals in the soil. Correspondingly, accumulation of nutrients in M. oleifera leaves increased with the addition of compost to the soil, except for cobalt and chromium. Trace elements had minimal bioavailability in the amended soils, and their presence in the leaves was lower than the permissible trace metal levels in food. The 30% combination had the highest concentration of calcium (45 042.5 mg/kg), magnesium (17430.0 mg/kg) and phosphorous (8802. 5 mg/kg) in M. oleifera leaves. The study concluded the addition of compost improved bioavailability of nutrients in the soil and their concentration in M. oleifera leaves. The target hazard quotients for heavy metals was less than one, indicating that M. oleifera leaf biomass harvested from soil amended with plant-based compost is safe for human consumption. These results serve as guidelines for recommended organic certification requiremets where plant-based compost is often used in the fast-growing herbal industry.

Determination and risk assessment of heavy metals in raw foodstuffs sold from open markets in Zambia; a comparison of Kabwe, Kitwe, and Lusaka towns

The research focused on risk assessment of some heavy metals in common vegetables and fish sold on open markets in three towns of Zambia. The mean level of heavy metals ranged as follows (mg/kg): 1.9 to 662.7, 3.0 to 3472.3 and 2.0 to 1698.7 of cadmium (lowest) and aluminium (highest) for samples from Kabwe, Kitwe and Lusaka, respectively. Statistical analysis indicated that the concentrations of samples from Kitwe and Lusaka towns were similar, P > 0.05. However, there were noteworthy differences in the mean amounts of heavy metals in samples from Kitwe and Kabwe, and samples from Kabwe and Lusaka towns, P < .0167. The health risk analysis indicates possible non-carcinogenic and carcinogenic risks to the consumer. This is because the hazard index (HI) for all metals in all samples from all towns was greater than 1 and the cancer risk (CR) for cadmium was above 10-4 in all samples from all towns.

Review of the Terminology, Approaches, and Formulations Used in the Guidelines on Quantitative Risk Assessment of Chemical Hazards in Food

This paper reviews the published terminology, mathematical models, and the possible approaches used to characterise the risk of foodborne chemical hazards, particularly pesticides, metals, mycotoxins, acrylamide, and polycyclic aromatic hydrocarbons (PAHs). The results confirmed the wide variability of the nomenclature used, e.g., 28 different ways of referencing exposure, 13 of cancer risk, or 9 of slope factor. On the other hand, a total of 16 equations were identified to formulate all the risk characterisation parameters of interest. Therefore, the present study proposes a terminology and formulation for some risk characterisation parameters based on the guidelines of international organisations and the literature review. The mathematical model used for non-genotoxic hazards is a ratio in all cases. However, the authors used the probability of cancer or different ratios, such as the margin of exposure (MOE) for genotoxic hazards. For each effect studied per hazard, the non-genotoxic effect was mostly studied in pesticides (79.73%), the genotoxic effect was mostly studied in PAHs (71.15%), and both effects were mainly studied in metals (59.4%). The authors of the works reviewed generally opted for a deterministic approach, although most of those who assessed the risk for mycotoxins or the ratio and risk for acrylamide used the probabilistic approach.

Concentrations and health risks of selected elements in leafy vegetables: a comparison between roadside open-air markets and large stores in Johannesburg, South Africa

This study compared concentrations and health risks of selected elements (Al, As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Zn) in leafy vegetables (coriander, lettuce, mint, spring onion, swiss chard) from roadside open-air markets (OM) and large stores (supermarkets: SM, vegetable markets: VM) in Johannesburg, South Africa. Along with washed leaves (OMW, SMW, VMW), unwashed OM leaves (OMUW) were assessed to investigate the contribution of deposition. The findings revealed that OMUW leaves had the highest concentrations of all elements. Furthermore, compared with washed leaves, OMUW leaves showed significantly higher (p < 0.05) mean concentrations of Cd, Hg, Ni and Pb, elements that typify the composition of polluted urban air. Bi- and multivariate analysis indicated anthropogenic origin of most elements in OM leaves and several in SMW and VMW leaves. Although only OMUW leaves exhibited hazard quotient above the safe threshold of 1 for Cd, Cr, As and Ni, hazard index exceeded this safe limit in all samples (OMUW (11.77) > OMW (1.83) > SMW (1.29) > VMW (1.01)). Determined cancer risk for Cd and As was greater than 1 × 10-6 in both washed and unwashed leaves, and the greatest cancer risk was estimated for OM leaves. Thorough washing of OM vegetables with water reduced non-carcinogenic risk (84%) and cancer risk (74‒87%) markedly. In conclusion, residents primarily relying on open-air markets for their regular leafy vegetable supplies might face far more severe lifelong health implications compared to customers of large stores in Johannesburg.

Trace elements in Foodstuffs from the Mediterranean Basin-Occurrence, Risk Assessment, Regulations, and Prevention strategies: A review

Trace elements (TEs) are chemical compounds that naturally occur in the earth's crust and in living organisms at low concentrations. Anthropogenic activities can significantly increase the level of TEs in the environment and finally enter the food chain. Toxic TEs like cadmium, lead, arsenic, and mercury have no positive role in a biological system and can cause harmful effects on human health. Ingestion of contaminated food is a typical route of TEs intake by humans. Recent data about the occurrence of TEs in food available in the Mediterranean countries are considered in this review. Analytical methods are also discussed. Furthermore, a discussion of existing international agency regulations will be given. The risk associated with the dietary intake of TEs was estimated by considering consumer exposure and threshold values such as Benchmark dose lower confidence limit and provisional tolerable weekly intake established by the European Food Safety Authority and the Joint FAO/WHO Expert Committee on Food Additives, respectively. Finally, several remediation approaches to minimize TE contamination in foodstuffs were discussed including chemical, biological, biotechnological, and nanotechnological methods. The results of this study proved the occurrence of TEs contamination at high levels in vegetables and fish from some Mediterranean countries. Lead and cadmium are more abundant in foodstuffs than other toxic trace elements. Geographical variations in TE contamination of food crops clearly appear, with a greater risk in developing countries. There is still a need for the regular monitoring of these toxic element levels in food items to ensure consumer protection.

Characteristics and Assessment of Soil Heavy Metals Pollution in the Xiaohe River Irrigation Area of the Loess Plateau, China

Heavy metals in soil are a potential threat to ecosystems and human well−being. Understanding the characteristics of soil heavy metal pollution and the prediction of ecological risk are crucial for regional eco−environment and agricultural development, especially for irrigation areas. In this study, the Xiaohe River Irrigation Area in the Loess Plateau was taken as the study area, and the concentration, as well as their accumulation degree and ecological risk and distribution of soil heavy metals, were explored based on the geo−accumulation index (Igeo) and Hakanson potential ecological risk index methods. The results showed that the concentrations of soil heavy metals were all lower than the second grade Environmental Quality Standard for Soils of China. However, the average concentrations of Cu, Hg, Cd, Pb, Zn, Ni and As were higher than the above−mentioned standard. Compared with the soil background values of Shanxi Province, eight heavy metals of all samples presented different accumulation degrees, with the highest accumulation degree in Hg, followed by Cd, and the values were 11.3 and 4.0 times more than the background value, respectively. Spatially, the distribution of soil heavy metals in the Xiaohe River irrigation area was quite different, generating diverse pollution patterns with significant regional differences and complex transportation routes. The content of soil heavy metals in the Xiaohe River irrigation area was highly affected by land use types. The pollution degree varied with the distance to an urban area, declining from the urban area to suburban farmland, and the outer suburban farmland. Among these heavy metals, Hg and Cd were the principal contamination elements, and transportation, service industry and agricultural activities were the main potential contamination sources. The potential ecological risk of soil heavy metal positioned as follows: Hg > Cd > Pb > Zn > Cu > As > Ni > Cr. As indicated by the Hakanson potential ecological risk index strategies, except for the Wangwu examining site, the other six sampling sites experienced extremely strong risks, and as a whole, the entire study region was in a condition of incredibly impressive perils. Consequently, these results suggest that improving soil environmental investigation and assessment, setting up soil heavy metal contamination prevention and control innovation framework and reinforcing contamination source control are effective approaches for soil heavy metal contamination anticipation and control in irrigated areas of the Loess Plateau.

Short−Term Assessment of Heavy Metals in Surface Water from Xiaohe River Irrigation Area, China: Levels, Sources and Distribution

The aims of this study were to determine the pollution characteristics of heavy metals and their potential harm to human health in the surface water of agricultural irrigation areas, China, over a short term. In this study, Cu, Zn, Pb, Hg, Ni, Cr, Cd, and As in surface water of the Xiaohe River irrigation area were detected and analyzed. The results showed that the concentrations of Pb, Hg, Ni, Cr, Cd, and As exceeded the national environmental quality standard for surface water in varying degrees. The concentrations of heavy metals in surface water in October were significantly lower than that in November and December due to the impact of extreme precipitation events. Point source pollution (industrial sewage, etc.) was the main factor affecting the spatial distribution of heavy metals. The main source of heavy metals in October was domestic sewage. Domestic sewage and industrial sewage were the main sources of heavy metals in November. The sources of heavy metals in surface water in December were relatively diverse, and industrial sewage was the main source. The temporal variation of heavy metal pollution sources changed significantly. Industrial sewage was the main pollution source of heavy metals in surface water in the study area. The impact of urban domestic sewage and agricultural activities cannot be ignored. The health risk of heavy metals in surface water mainly depends on Cr, Cd, and As. Policy recommendations were also proposed for better control of heavy metal pollution in the surface water of river ecosystems involving agricultural irrigation areas.

Evaluation of metallic trace elements contents in some major raw foodstuffs in Burkina Faso and health risk assessment

Diet based on cereal, vegetables, oleaginous and dried fish are providing essential metallic elements. It can be also a source of exposure to toxic metallic elements. The aims of this study were to evaluate the contents on nine metallic trace elements (Fe, Zn, Mn, Co, Cd, Pb, Cu, Ni, Cr) in some major raw foodstuffs including rice, maize, peanut, tomato and dried fish in Burkina Faso and assess the health risk of these elements. Two hundred twenty-two samples were collected and analyzed by atomic absorption spectrometry. The health risk assessment was based on the United States Environment Protection Agency (USEPA) model. Iron and Zinc were the elements with the highest concentrations in the investigated foodstuffs. The iron highest median value (68.80 mg/kg) was observed in dried fish followed by maize (43.09 mg/kg) and peanuts (28.92 mg/kg). Rates of 77.95%, 66.66% and 32.5% obtained respectively fro tomato, maize and rice samples were above the maximum limit of lead set by Codex Alimentarius while 47.6%, 71.16% and 0% of maize, tomato and rice samples respectively have shown concentration above the maximum limit of cadmium. Chromium had shown higher contribution rate to the maximum daily intake of 167.11%, 34%, 2% and 8.53% for rice, maize and peanut respectively. A non-cancer risk situation has been observed on rice, maize and peanut consumption. None of the index risk values was above the threshold set by USEPA.

Quantification and health risk assessment of lead and cadmium in wheat, rice, and their processed products from Peru

In Peru, rice grains, wheat, and their processed products are accessible due to their low cost; however, their sale does not have quality certification, so their safety is not guaranteed. This study quantified lead (Pb) and cadmium (Cd) by voltammetry in 16 samples of grains and processed products from four markets in Arequipa (Altiplano, Andrés Avelino Cáceres, Los Incas, and San Camilo) and evaluated their potential health risk. The maximum concentrations of Pb in rice, wheat, and their processed products were 4.821 mg/kg, 7.962 mg/kg, 4.717 mg/kg, and 6.440 mg/kg, respectively; only seven samples showed Cd. All samples exceeded the maximum level (ML) for Pb, and four samples exceeded the ML for Cd established by the Codex Alimentarius (0.200 mg/kg); the rice product had the highest concentration of Pb and Cd. In relation to the estimation of potential health risk, the estimated daily intake (EDI), target hazard quotient (THQ), and target cancer risk (TR), showed that the consumption of all processed rice and wheat products (except Andrés Avelino Cáceres rice and San Camilo wheat) represent a health threat associated with an increased probability of cancer development.

The effects of Daucus carota extract against PC3, PNT1a prostate cells, acetylcholinesterase, glutathione S-transferase, and α-glycosidase; an in vitro-in silico study

Daucus carota L. ssp. major (DCM) plant is widely used in traditional medicine to treat some types of cancer and various diseases. Therefore, we evaluated the biological activities of this plant to define its effects against prostate cancer (PCa), Alzheimer's disease (AD), oxidation, and diabetes mellitus (DM) as well as identified its phenolic composition. To determine the anti-cancer properties of the plant extract, we treated PCa cells with the extract at a concentration range of 0.25, 0.5, 1, 2, and 4 mg/ml. Significant results were obtained against the PC3 cells compared to normal PNT1a prostate epithelial cells. As a result of precise measurements at the millimolar level, it was observed that the plant extract showed an effective inhibition (IC₅₀ ) against glutathione S-transferase (GST; 12.84 mM), acetyl cholinesterase (AChE; 15.07 mM), and α-Gly (11.75 mM) enzymes when compared with standard inhibitors. Antioxidant activities of DCM methanol extract were determined via two well-known in vitro techniques. The extracts showed antioxidant activities against the DPPH and ABTS⁺ . The LC-ESI-MS/MS was used to determine the phenolic compounds of methanol extract from DCM. Chlorogenic acid (2,089.096 µg/g), shikimic acid (193.14 µg/g), and coumarin (113.604 µg/g) were characterized as major phenolic compounds. In addition, the interactions of chlorogenic acid, chrysin, coumarin, and shikimic acid with the used three enzymes have been calculated using molecular docking simulation. PRACTICAL APPLICATIONS: Plant natural phenolic compounds have protective effects such as anti-inflammatory, antioxidant, anticarcinogen, and enzyme inhibitory. Therefore, it has an important place in the food and pharmaceutical industry. The present study aims to reveal the enzyme inhibitory, antioxidant, and anticarcinogenic properties of the Daucus carota ssp. Major (DCM) plant extract. Significant results were obtained against the PC3 cells compared to normal PNT1a prostate epithelial cells. DCM extract demonstrated considerable antioxidant activity and inhibitory potential on used metabolic enzymes. These biological effects are thought to have a relationship with rich chemical composition.

Heavy Metals and Human Health: Possible Exposure Pathways and the Competition for Protein Binding Sites

Heavy metals enter the human body through the gastrointestinal tract, skin, or via inhalation. Toxic metals have proven to be a major threat to human health, mostly because of their ability to cause membrane and DNA damage, and to perturb protein function and enzyme activity. These metals disturb native proteins’ functions by binding to free thiols or other functional groups, catalyzing the oxidation of amino acid side chains, perturbing protein folding, and/or displacing essential metal ions in enzymes. The review shows the physiological and biochemical effects of selected toxic metals interactions with proteins and enzymes. As environmental contamination by heavy metals is one of the most significant global problems, some detoxification strategies are also mentioned.

Occurrence and dietary exposure of heavy metals in marketed vegetables and fruits of Shandong Province, China

The contamination of heavy metals in vegetables and fruits is a serious threat to food safety and human health. The present study was designed to investigate the occurrence and dietary exposure of lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg) in vegetables and fruits in Shandong Province, China. Results demonstrated that the mean level of total heavy metals was 30.25 µg/kg. The most frequently found heavy metal was Cd (69.2%) with a mean value of 11.54 µg/kg. The mean exposure values of Pb, As, Cd, and Hg in vegetables were 0.052, 0.045, 0.038, and 2.40 × 10-3 µg/kg bw/day, respectively. Moreover, the calculated hazard quotient (HQ) values of mean levels for these four heavy metals were all less than 1, indicating the health risk of heavy metal exposure caused by vegetable consumption was low. This study has displayed baseline information on heavy metal contamination in vegetables and fruits, which can provide useful data support for the formulation of relevant standards and government management.

Heavy metal contamination and health risk assessment in grains and grain-based processed food in Arequipa region of Peru

Heavy metals (HMs) in crops and processed foods are a concern and pose a potential serious health hazard. This study investigated possible presence of HMs in grains and processed products in the Region of Arequipa in Peru. Concentrations of Cd, As, Sn, Pb, and Hg were determined for commonly consumed grains in 18 districts of the region and processed products from 3 popular markets of Arequipa city, using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Cold Vapor Atomic Absorption Spectroscopy (CVAAS). HM concentrations above the Codex General Standard limits were found for As (0.17 mg kg^-1) and Cd (0.11 mg kg^-1) in cereal grains. Elevated Pb concentrations of 0.55, 0.75, and 5.08 mg kg^-1 were found for quinoa, maize, and rice products, respectively; and attributed to processing conditions. The Total Hazard Index (HI) for polished rice and rice products had values between 1 and 10, showing non-carcinogenic adverse effects. Total Target Cancer Risk (TR_T) and uncertainty analysis of percentile P_90% for polished rice and quinoa products gave values above permissible limit of 10^-4, indicating an unacceptable cancer risk. The Nemerow Composite Pollution Index method (NCPI) showed that processed products had a significant pollution level due to the presence of Pb. While most crops grains had acceptable low HM levels, this is the first report of concerning HM concentrations in some consumed grains and processed products in southern Peru and indicates the necessity to find ways to decrease certain toxic metals in foods.

Assessment of Heavy Metal Contamination and the Probabilistic Risk via Salad Vegetable Consumption in Tabriz, Iran

Considering the importance of vegetables as a source of micronutrients and fibers in a balanced diet, there is still a concern that vegetables could also be a source of toxic heavy metal contaminants. The study aimed to determine the concentrations of lead (Pb), cadmium (Cd), arsenic (As), chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn) in the salad vegetables sold in Tabriz city, Iran, and to evaluate the probabilistic health risk assessment. The amount of toxic metals in 240 samples was evaluated by atomic absorption spectrophotometer (AAS) method. The average levels of toxic metals in the samples were found to be 1.59, 1.26, 1.42, 4.89, 13.38, 1.01, and 32.65 mg/kg for Pb, Cd, As, Cr, Cu, Ni, and Zn, respectively. According to the results, Zn and Cu had the highest concentration, whereas the lowest concentration belonged to Ni. The rank order of the toxic elements in the samples based on target hazard quotient (THQ) values was Cr > Cd > As > Pb > Cu> Zn > Ni, for both females and males. Leafy vegetables had a higher amount of total target hazard quotient (TTHQ) than tuber crops for both males and females. The carcinogenic risks of As and Pb were 0.032 and 0.03 in the females and 0.22 and 0.19 in males. According to the finding, there may be a potential risk of toxic metals, especially Cr, Cd, and As, for both females and males in Tabriz through the consumption of vegetables.

Analysis of Heavy Metal Content in Soil and Plants in the Dumping Ground of Magnesite Mining Factory Jelšava-Lubeník (Slovakia)

A high content of heavy metals in the soil and plants of a magnesite mining area might cause serious damage to the environment and can be a threat to the health of the surrounding population. This paper presents the results of research that focused on analyzing the heavy metal content in soil and plants in the dumping grounds of the magnesite mining factory Jelšava-Lubeník (Slovakia). The analysis focused on the content of heavy metals in soil (X-ray fluorescence spectrometry, atomic absorption spectrometry), in plants (inductively coupled plasma mass spectrometry, inductively coupled plasma atomic emission spectrometry), and pH (1M KCl solution). The results showed that the soil in the study area was slightly acidic to strongly alkaline and the content of Cr, As, Mn, and Mg exceeded by several times the limit values for the Slovak Republic. The results of the hierarchical cluster analysis and the correlation analysis show that the grouped metals come from the same sources of pollution. The content of heavy metals in plants was high and the highest concentration was found in the roots of Elytrigia repens > Agrostis stolonifera > Phragmites australis and flowers of Phragmites australis. The findings confirmed the suitability of the used plants in the process of phytoextraction and phytostabilization. The acquired knowledge can help in planning and realization remediation measures and improve the state of the environment in areas exposed to magnesite mining.

Comparison of trace element concentrations in freshwater fish and marine fish consumed in Shandong Province, China, and their potential risks to human health

This study provides the primary data of ten trace element concentrations from four highly consumed cultured freshwater fish species in comparison to six marine fish collected from markets of the Shandong province, China, and evaluates the potential human health risks from consuming these fish. A significant difference in five metal concentrations (Cr, As, Se, Cd, Pb) was found between freshwater and marine fish. With the exception of chromium, the other four element contents in marine fish were higher than those in freshwater fish. According to estimated daily intake (EDI), target hazard quotient (THQ), total target hazard quotient (TTHQ), and the permissible safety limits prescribed by various agencies, consumption of the examined fish species is safe for human health. However, chromium in freshwater fish and arsenic in marine fish should still be a cause for concern in terms of human health, especially for fisher folk communities and populations that frequently consume fish.

Assessment of Mineral and Phenolic Profiles and Their Association with the Antioxidant, Cytotoxic Effect, and Antimicrobial Potential of Lycium chinense Miller

This study aimed at investigating the Lycium chinense Miller leaf extract mineral and phenolic compound profiles as well as antioxidant and antimicrobial potential. We determined the leaf extract mineral composition, identified its major mineral components, and quantified secondary metabolites. We also measured the leaf extract antioxidant potential and found that it varies in a concentration-dependent manner. We observed a significant and higher positive correlation between DPPH and ABTS assays compared with the total phenolic and flavonoid content. Furthermore, our assay results positively correlated with several observed acids, indicating their strong association with the L. chinense antioxidant potential. Our cytotoxic assay revealed weak toxicity at higher tested concentrations. Our MIC assay showed that the 80% methanol extract effectively inhibited the growth of Escherichia coli Castellani and Chalmers (ATCC35150). The 625-ppm leaf extract completely suppressed the growth of Staphylococcus aureus Rosenbach (ATCC13150), Bacillus cereus (ATCC 14579), and Helicobacter pylori (ATCC43504). These results allow us to understand the indigenous medicinal value of L. chinense. Our study suggests that the L. chinense leaf extract phenolic compounds possess a good antioxidant activity against free radicals and are effective antimicrobial agents. Finally, the presence and high level of diverse minerals suggest the potential of L. chinense for nutraceutical and functional food applications.

Heavy metal concentration, potential ecological risk assessment and enzyme activity in soils affected by a lead-zinc tailing spill in Guangxi, China

In 1976, a tailing dam collapse accident at the Xingping Lead-Zinc Mine in Guangxi Province, China, led to the spillage of mining wastewater and sludge into downstream agricultural lands in Side Village. Heavy metal concentrations, soil pollution and soil enzyme activity were analysed to understand the pollution characteristics of the agricultural lands along the Side stream by this accident. The tailing soil (TS), natural forest soil without spill contamination (NFS) and four representative agricultural soils were selected. The four agricultural soil sites located at the entrance of the stream to the agricultural soil (EnS), the upstream region (US), the middle stream (MS) and at the exit of the stream (ExS) from the village, respectively. The results showed that the soil pH values and heavy metal concentrations were in the order of tailing soil TS > ExS > MS > US > EnS > NFS. The concentration of Pb ranked highest among the analysed elements followed by Zn, Cd, Mn and Cu. The concentrations of Pb, Zn, Cd Mn and Cu 10530.41, 1708.58, 8.32, 885.61 and 104.51 mg kg^-1, respectively. Soil pollution assessments by single pollution index, synthesis pollution index and individual/comprehensive potential ecological risk analysis explicated all the soils reached the heavily polluted level and presented extremely high ecological risk grades. Pb, Zn and Cd were the dominant pollutants. The soil enzyme activities of invertase, protease and urease exhibited the opposite distribution pattern as those of the heavy metal concentrations, while the inversely results were observed for the activity of catalase.

Health risks from trace elements in muscles of some commonly available fish in Australia and India

The levels of trace elements (As, Hg, Cr, Cd, Pb, Co, Ni, Cu, Mn and Zn) in commercially important fish species sampled from fish markets of Adelaide, Australia; canned fish from South Australian supermarkets; and fish markets of West Bengal, India were determined by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Mercury was determined by using triple quadrupole ICP-MS. The accuracy of the methods was assessed with a certified standard reference material (NRCC-DORM-3 dogfish protein), and the results were compared with values reported in the literature. The results indicated considerable variations in the accumulation of trace elements among the fish species. The relationship between species with respect to trace element concentrations was examined using cluster analysis, which showed Indian fish species forming distinct groups from the others. Other than As in sardines, whiting and snapper and Hg in swordfish and snapper, the trace element concentrations were within permissible limits recommended by various standards. Based on the estimated daily intake (EDI), fish samples analysed in this study can be considered safe for human consumption as per the recommended daily dietary allowance limit fixed by various agencies. Continuous monitoring and assessments of fish metal(loid) content are needed to generate more data and safeguard human health.

Occurrence of Trace Metals in Food Crops Grown on the Mbale Dumpsite, Uganda, and Human Health Risks

Food crops can be used as biomonitors to assess potential public health food safety hazards from contaminated agricultural environments. Globally, more than 800 million people grow fruits, vegetables, and grains on urban garden soils with unknown health risks. This worldwide practice has exposed consumers to pathogenic and carcinogenic risks from locally grown and imported contaminated foodstuffs such as Amaranthus cruentus and Zea mays, traditional and widely consumed crops across the globe. This study used Z. mays and A. cruentus crops to investigate the occurrence and spatial variations of aluminum (Al), chromium (Cr), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), mercury (Hg), and lead (Pb) concentrations across the Mbale dumpsite, Uganda. Mean concentrations for Fe, Al, Zn, Mn, and Cu were high in both crops, whereas Pb, Cr, Co, Cd, As, Hg, Se, and Ni occurred in trace amounts. Using the 2 crops as biomonitors, significant variations for Al, Zn, Fe, Cr, and Co concentrations in individual crops were identified across the dump center, hill slope, and riverbank. The variations in Al, Zn, Fe, Cr, and Co concentrations were specific for crop types, crop parts, and location. The highest overall accumulation of metals was at the dump center and in crop leaves. Except Pb concentrations in Z. mays seeds, Cr, Pb, Zn, and Al concentrations in other crop parts were above World Health Organization/Food and Agricultural Organization consumer food safety limits. Therefore, Z. mays and A. cruentus consumption could pose health risks to consumers. Further health assessments and potential regulations are recommended to reduce potential health risks from metals in crops for human consumption. Integr Environ Assess Manag 2020;16:362-377. © 2019 SETAC.

A review: Recent advances in ultrasensitive and highly specific recognition aptasensors with various detection strategies

One of the most studied topics in analytical chemistry and physics is to develop bio-sensors. Aptamers are small single-stranded RNA or DNA oligonucleotides (5-25 kDa), which have advantages in comparison to their antibodies such as physicochemical stability and high binding specificity. They are able to integrate with proteins or small molecules, including intact viral particles, plant lectins, gene-regulation factor, growth factors, antibodies and enzymes. The aptamers have reportedly shown some unique characteristics, including long shelf-life, simple modification to provide covalent bonds to material surfaces, minor batch variation, cost-effectiveness and slight denaturation susceptibility. These features led important efforts toward the development of aptamer-based sensors, known as apta-sensors classified into optical, electrical and mass-sensitive based on the signal transduction mode. This review provided a number of current advancements in selecting, development criteria, and aptamers application with the focus on the effect of apta-sensors, specifically for disease-associated analyses. The review concentrated on the current reports of apta-sensors that are used for evaluating different food and environmental pollutants.

Selective pressurized hot water extraction of nutritious macro-nutrients vs. micro-nutrients in Moringa oleifera leaves-a chemometric approach

Moringa oleifera leaves are widely used in traditional medicine as a food supplement because they are high in essential and nutritious content. Pressurized hot water extraction (PHWE), which is a green approach, was used for the recovery of the macro-nutrient and micro-nutrient elements from dried leaf powder of Moringa oleifera. In this study, response surface methodology was applied to assess the influence of temperature (50-200 °C) and time (5-60 min) on the extractability pattern of macro-nutrient and micro-nutrient elements from the leaves of Moringa oleifera when processed by PHWE. The quantification of macro-nutrient elements such as Ca, K and Mg and micro-nutrient elements like Al, Co, Cr, Cu, Fe, Ni and Zn from the leaves was determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Obtained results revealed that the extraction of macro-nutrient elements from the Moringa oleifera leaves was enhanced by increasing the extraction time more than the extraction temperature. On the contrary, the amounts of extractable micro-nutrient elements were increased by increasing the extraction temperature. Hence, the recovery for macro-nutrient elements ranged from 88 to 98% while for micro-nutrients it ranged from 21 to 46%. This implies that macro-nutrient elements are extracted with relatively high selectivity in relation to micro-nutrient elements in Moringa dried leaf powder using the PHWE technique.

Developments and applications of nanomaterial-based carbon paste electrodes

This review summarizes the progress that has been made in the past ten years in the field of electrochemical sensing using nanomaterial-based carbon paste electrodes. Following an introduction into the field, a first large section covers sensors for biological species and pharmaceutical compounds (with subsections on sensors for antioxidants, catecholamines and amino acids). The next section covers sensors for environmental pollutants (with subsections on sensors for pesticides and heavy metal ions). Several tables are presented that give an overview on the wealth of methods (differential pulse voltammetry, square wave voltammetry, amperometry, etc.) and different nanomaterials available. A concluding section summarizes the status, addresses future challenges, and gives an outlook on potential trends.

This review summarizes the progress that has been made in the past ten years in the field of electrochemical sensing using nanomaterial-based carbon paste electrodes.

ICP-MS and HPLC analyses, enzyme inhibition and antioxidant potential of Achillea schischkinii Sosn

Achillea schischkinii Sosn. is an endemic plant species and it belongs to Asteraceae family. It is distributed widely in the Central and East Anatolia. This study was carried out for evaluation of the antioxidant activity, enzyme inhibition effect, elemental and phenolic content of A. schischkinii. Briefly, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glycosidase (α-Gly), and glutathione S-transferase (GST) enzymes were strongly inhibited by A. schischkinii. IC₅₀ values for AChE, BChE, α-Gly, and GST enzymes were found as 19.3 mg/mL, 15.4 mg/mL, 69.3 mg/mL, and 34.7 mg/mL respectively. The antioxidant activity of the sample was evaluated by four different in vitro bioanalytical methods. Besides, the concentrations of twelve elements in A. schischkinii were analyzed by ICP-MS technique. Zn (50.6 ppm), Mn (23.0 ppm), and Cu (12.7 ppm) were found as major elements. Furthermore, catechin (20.8 µg/mg extract), trans-ferulic acid (18.3 µg/mg extract), and gallic acid (11.2 µg/mg extract) were characterized as major phenolic compounds by using HPLC. PRACTICAL APPLICATIONS: Acetylcholinesterase, butyrylcholinesterase, α-glycosidase, and glutathione s-transferase enzymes have crucial functions on metabolism. Enzyme inhibition or activation mostly attributed to some health disorders such as Alzheimer's disease, Diabetes mellitus, cancer and hyperglycemia. Phenolic contents are responsible for effective biological activity. This study evaluated the phenolic content and antioxidant activity of Achillea schischkinii as well as the inhibition effect against four metabolic enzymes. The results would be beneficial for using the plant in the food industry and pharmacological process.

Mercury pollution in modern times and its socio-medical consequences

Mercury plays a critical role in serious health problems due to environmental or occupational exposures. Aquatic ecosystems are an essential component of the global biogeochemical cycle of mercury, as inorganic mercury can be converted to toxic methyl mercury in these environments and reemissions of elemental mercury rival anthropogenic mercury releases on a global scale. The history of the Minamata disease, a typical example of industrial pollution, has shown how corporate secrecy and ignorance on part of the health authorities may influence the devastating spread of environmental contamination and the progress of disease. While the Minamata Convention, in place since 2017, is aiming to lower mercury exposure and to prevent adverse effects, there are still knowledge gaps in the areas of global environmental mercury exposure. Areas of uncertainty in the global biogeochemical cycle of mercury include oxidation processes in the atmosphere, land-atmosphere and ocean-atmosphere cycling, and methylation processes in the ocean. Pollution related to climate change (especially in boreal and arctic regions), bioaccumulation and biomagnification of methyl mercury in the food chain, especially in fish and marine mammals, needs to be addressed in more detail. Information is lacking on numerous hidden contaminant exposures i.e. from globally applied traditional medicine, mercury containing skin creams and soaps, dental amalgam, ethyl mercury containing vaccines and latex paint additives, as well as on mercury releases from power plants, e-waste/fluorescent lamps, wildfire emissions, and global artisanal small-scale gold mining activities. Mercury occurs in various forms with different levels of toxicity. While much is already known and documented on the health effects of mercury, present knowledge and translation into preventive actions is still incomplete. Risks for long term health effects trough prolonged low dose exposure and trough cumulative exposures of various mercury forms should be further addressed. Preventive actions should include adequate human biomonitoring programs. Research data should be translated swiftly into management tools for local policy makers and health professionals, also paying attention at the major differences in mercury contamination across the globe.

Concentrations and health risks of heavy metals in soils and crops around the Pingle manganese (Mn) mine area in Guangxi Province, China

Heavy metal concentrations in agricultural fields and their ecological risks are a source of extensive concern worldwide. A field survey was conducted to investigate the present situation and health risks of heavy metals (Mn, Pb, Zn, Cu, and Cd) and crops (corn, green soybean, sweet potato, persimmon, cassava, and Chinese chestnut) around the Pingle manganese (Mn) mine site in Guangxi Province, China, which was abandoned 20 years ago. The results showed that the ranges of Mn, Pb, Zn, Cu, and Cd were 2706.54-6760.16, 229.37-275.84, 160.39-215.48, 58.11-75.30, and 5.78-6.98 mg kg^-1, respectively, which were approximately 15.38-38.41, 11.76-14.15, 2.12-2.85, 2.09-2.71, and 21.64-28.75 times greater than their respective background values. Most of these concentrations exceeded the national standard for soil quality (grade 2) developed by the Ministry of Environmental Protection of China (1995). Contamination assessments based on the single contamination index (P_i), Nemerow multi-factor index (P_com), and potential ecological risk index (RI) showed that the sampled soils were severely polluted with these heavy metals, especially Pb and Cd. Similarly, the crops were enriched with Pb and Cd, with concentrations of 10.22-41.78 and 2.33-5.37 mg kg^-1, respectively, which were much higher than the threshold values of the national food standards. Contamination assessments with P_i and P_com also showed that the crops were severely polluted with Pb and Cd. The bioaccumulation factor values for Cd were highest among the heavy metals, with an average mean of 0.66 in these six crops, demonstrating that Cd readily accumulates in these crops. An assessment showed that the health risk for adults living in the mining-impacted areas was significant. Our study strongly recommends that heavy metal contamination in agricultural soils and crops grown around the Pingle Mn mining-affected areas should be treated to mitigate the health risks.