Toxicological potential of cobalt in forage for ruminants grown in polluted soil: a health risk assessment from trace metal pollution for livestock

Meta-metabolomic responses of river biofilms to cobalt exposure and use of dose-response model trends as an indicator of effects

The response of the meta-metabolome is rarely used to characterize the effects of contaminants on a whole community. Here, the meta-metabolomic fingerprints of biofilms were examined after 1, 3 and 7 days of exposure to five concentrations of cobalt (from background concentration to 1 × 10-5 M) in aquatic microcosms. The untargeted metabolomic data were processed using the DRomics tool to build dose-response models and to calculate benchmark-doses. This approach made it possible to use 100% of the chemical signal instead of being limited to the very few annotated metabolites (7%). These benchmark-doses were further aggregated into an empirical cumulative density function. A trend analysis of the untargeted meta-metabolomic feature dose-response curves after 7 days of exposure suggested the presence of a concentration range inducing defense responses between 1.7 × 10-9 and 2.7 × 10-6 M, and of a concentration range inducing damage responses from 2.7 × 10-6 M and above. This distinction was in good agreement with changes in the other biological parameters studied (biomass and chlorophyll content). This study demonstrated that the molecular defense and damage responses can be related to contaminant concentrations and represents a promising approach for environmental risk assessment of metals.

Emerging insights into the impacts of heavy metals exposure on health, reproductive and productive performance of livestock

Heavy metals, common environmental pollutants with widespread distribution hazards and several health problems linked to them are distinguished from other toxic compounds by their bioaccumulation in living organisms. They pollute the food chain and threaten the health of animals. Biologically, heavy metals exhibit both beneficial and harmful effects. Certain essential heavy metals such as Co, Mn, Se, Zn, and Mg play crucial roles in vital physiological processes in trace amounts, while others like As, Pb, Hg, Cd, and Cu are widely recognized for their toxic properties. Regardless of their physiological functions, an excess intake of all heavy metals beyond the tolerance limit can lead to toxicity. Animals face exposure to heavy metals through contaminated feed and water, primarily as a result of anthropogenic environmental pollution. After ingestion heavy metals persist in the body for an extended duration and the nature of exposure dictates whether they induce acute or chronic, clinical or subclinical, or subtle toxicities. The toxic effects of metals lead to disruption of cellular homeostasis through the generation of free radicals that develop oxidative stress. In cases of acute heavy metal poisoning, characteristic clinical symptoms may arise, potentially culminating in the death of animals with corresponding necropsy findings. Chronic toxicities manifest as a decline in overall body condition scoring and a decrease in the production potential of animals. Elevated heavy metal levels in consumable animal products raise public health concerns. Timely diagnosis, targeted antidotes, and management strategies can significantly mitigate heavy metal impact on livestock health, productivity, and reproductive performance.

Forage accumulation of potentially toxic elements (PTEs) from soils around Kilembe copper mine, Western Uganda

Past copper mining within Kilembe valley between 1956-1982 left behind mine tailings rich in potentially toxic elements (PTEs). This study was conducted to assess the concentrations of PTEs in soils and the potential uptake by forage. Tailings, soils and forage were collected and analyzed using ICP-MS. The study established that over 60% of grazed plots contained high concentrations of Cu, Co, Ni and As. Copper in 35%, Co in 48% and Ni in 58% of forage soil plots exceeded the thresholds for agricultural soils. Bio-accumulation of Zn and Cu, was observed. Zinc in 14% of guinea grass (Panicum maximum), 33% coach grass (Digitalia Scarulum) and in 20% of elephant grasses (Penisetum perpureun) exceeded thresholds of 100-150 mg kg-1. Copper (Cu) concentrations in 20% of Penisetum perpureun and 14% of Digitalia Scarulum exceeded grazing thresholds of 25 mg kg-1. Containment of tailing erosion should be explored to control erosion of tailings into grazing areas.

Does Industrial Wastewater Irrigation Cause Potentially Toxic Metal Contamination and Risk to Human Health? Sugar Industry Wastewater and Radish Examples

The goal of this study was to appraise potentially toxic metal contents in the soil-radish system in industrial wastewater irrigated areas. The analysis of metals in water, soil and radish samples were performed with spectrophotometric method. The potentially toxic metal values in the wastewater irrigated radish samples were ranged from 1.25 to 1.41, 0.02 to 0.10, 0.77 to 0.81, 0.72 to 0.80, 0.92 to 1.19, 0.69 to 0.78, 0.08 to 0.11, 1.64 to 1.67 and 0.49 to 0.63 mg/kg for Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn and Mn, respectively. The potentially toxic metal values in the soil and radish samples irrigated with wastewater were lower than the maximum allowable limits, except for Cd. The results of the Health Risk Index evaluation conducted in this study also showed that the accumulations of Co, Cu, Fe, Mn, Cr, and Zn, especially Cd, pose a health risk in terms of consumption.

Bubalus bubalis Blood as Biological Tool to Track Impacts from Cobalt: Bioaccumulation and Health Risks Perspectives from a Water-Soil-Forage-Livestock Ecosystem

Cobalt (Co) bioaccumulation, contamination, and toxicity in the soil environment, plant growth, and cattles' health are becoming a severe matter that can cause unembellished consequences in environmental safety and human health. The present research was conducted for the assurance of cobalt (Co) amassing in three forage plant species (Zea mays, Sorghum bicolor, Trifolium alaxandrium), from four ecological sites, and sewage water and in buffaloes blood was investigated. The analysis of variance showed significant differences for Co concentration in the soil and sewage water collected from all ecological sites. Meanwhile, summer and winter seasons and forage ecotypes significantly influenced the quantity of Co. The forage pastures also vary significantly in the concentration of Co in the above-ground parts. The highest Co level was present in Trifolium alaxandrium at ecological site-5. Cobalt taken from wastewater had a higher concentration in Trifolium alaxandrium during the winter. The samples which are collected from site-V and site-IV have the maximum concentration of Co because these areas receive highly contaminated water for irrigation. Cobalt tends to be bioaccumulated in the food chain and can cause serious problems in humans and animals. Bioaccumulation of cobalt in collected samples could be accredited to anthropogenic activities. Pollution load index values for all samples fell in the range below 1. The health risk index indicated the probability of health damage caused by the ingestion of contaminated fodder. An increase of Co concentration in soil, fodder, and blood owing to wastewater irrigation to crops was indicated as an outcome of this investigation. The results indicate that the Co toxicity in forage crops is attributed to Co bioaccumulation, transfer, and pollution load in the soil-water-cattle triangle. Efforts should be extended to avoid contamination of the food chain via Co-rich sewage water. Other nonconventional water resources should be used for forage irrigation.

Primer-Engineered Transferase Enzyme for One-Pot and Amplified Detection of Cobalt Pollution and Peptide Remover Screening

Extensive consumption of cobalt in the chemical field such as for battery materials, alloy, pigments, and dyes has aggravated the pollution of cobalt both in food and the environment, and assays for its on-site monitoring are urgently demanded. Herein, we utilized enzyme dependence on metal cofactors to develop terminal transferase (TdT) as a recognition element, achieving a one-pot sensitive and specific assay for detecting cobalt pollution. We engineered a 3'-OH terminus primer to improve the discrimination capacity of TdT for Co²⁺ from other bivalent cations. The TdT extension reaction amplified the recognition of Co²⁺ and yielded a limit of detection of 0.99 μM for Co²⁺ detection. Then, the TdT-based assay was designed to precisely detect cobalt in food and agricultural soil samples. By end-measurement of fluorescence using a microplate reader, the multiplexing assay enabled the rapid screening of the peptide remover for cobalt pollution. The TdT-based assay can be a promising tool for cobalt pollution monitoring and control.

Cobalt availability in the soil plant and animal food chain: a study under a peri-urban environment

Cobalt metal is considered as an essential trace element for the animals. Present investigation was undertaken in the peri-urban area to analyze the cobalt availability in animal food chain by using different indices. Cow, buffalo and sheep samples along with forage and soil samples were collected from the three different sites of District Jhang and analyzed through atomic absorption spectrophotometer. Cobalt values differed in soil samples as 0.315-0.535 mg/kg, forages as 0.127-0.333 mg/kg and animal samples as 0.364-0.504 mg/kg. Analyzed cobalt concentration in soil, forage and animal samples was found to be deficient in concentration with respect to standard limits. Soil showed the minimum cobalt level in Z. mays while maximum concentration was examined in the forage C. decidua samples. All indices examined in this study has values lesser than 1, representing the safer limits of the cobalt concentration in these samples. Enrichment factor (0.071-0.161 mg/kg) showed the highly deficient amount of cobalt enrichment in this area. Bio-concentration factor (0.392-0.883) and pollution load index (0.035-0.059 mg/kg) values were also lesser than 1 explains that plant and soil samples are not contaminated with cobalt metal. The daily intake and health risk index ranged from 0.00019-0.00064 mg/kg/day and 0.0044-0.0150 mg/kg/day respectively. Among the animals, cobalt availability was maximum (0.0150 mg/kg/day) in the buffaloes that grazed on the C. decidua fodder. Results of this study concluded that cobalt containing fertilizers must be applied on the soil and forages. Animal feed derived from the cobalt containing supplements are supplied to the animals, to fulfill the nutritional requirements of livestock.

Potentially Toxic Metal Accumulation in Spinach (Spinacia oleracea L.) Irrigated with Industrial Wastewater and Health Risk Assessment from Consumption

This study aimed to determine the potentially toxic metal contents in soil and spinach samples in areas irrigated with industrial wastewater and to evaluate the potentially toxic metal accumulation in spinach samples according to pollution indices. Water, soil and spinach samples were analysed using atomic absorption spectrophotometer (Perkin-Elmer AAS-300). In this study, it was determined that the potentially toxic metal values ​​in the spinach samples irrigated with groundwater and sugar industry wastewater varied between 1.59 and 1.84, 0.22-0.68, 0.56-1.14, 1.41-1.56, 1.62-3.23, 0.57-1.02, 0.86-1.33, 0.20-0.32 and 0.35-2.10 mg/kg for Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn and Mn, respectively. It was concluded that the difference between the metal values ​​in the spinach samples according to the irrigation sources was statistically significant, except for Cu and Pb (p > 0.05). According to the results of this study, there is no health risk for Pb, Co and Cr with HRI values ​​below 1.0, while there is a risk for Cd, Cu, Fe, Ni, Mn and Zn. The much higher HRI values ​​of Cd than 1 (196.8 and 169.6) suggested that this metal is likely to cause significant health problems in the region.

Appraising growth, daily intake, health risk index, and pollution load of Zn in wheat (Triticum aestivum L.) grown in soil differentially spiked with zinc

Zinc (Zn) is a vital nutrient element required for plants normal growth and development. It performs imperative functions in numerous metabolic pathways in the plants. However, potentially noxious levels of Zn in terrestrial environment can lead to inhibited photosynthesis, growth, respiratory rate and imbalanced mineral nutrition. In micronutrient malnutrition, Zn deficiency is a global human health problem owing to the human dependence on cereals grains especially wheat-based diet. Therefore, this study investigated the Zn uptake efficacy in Triticum aestivum that is grown under two different doses (100 g/kg or 200 g/kg) of various soil amendments in both pot and field experimentation. Results of this study revealed that mean Zn concentration in different wheat varieties and treatments were varied from 1.53 to 6.03 mg/kg, 11.27 to 40.65 mg/kg, 11.28 to 39.93 mg/kg, and 11.32 to 37.70 mg/kg in amended soil, root, shoot, and grains, respectively. All observed Zn values in soil and wheat parts were lower than the FAO/WHO standards. Zinc values observed for pollution load index (0.034-0.134 mg/kg), daily intake (0.00492-0.01533 mg/kg), and health risk (0.0164-0.0570 mg/kg) index were lower than 1 except bio-concentration factor. Bio-concentration factor (5.076-10.165 mg/kg) revealed that DHARABI-11 variety showed maximum Zn uptake efficacy in farmyard manure treatment. The daily intake and health risk index values also showed that Zn level in grains is safe for inhabitants consumption. Overall, study recommended that these organic amendments are a good source of fertilizers, essentially required for the sustainable management of soil and increases the Zn accumulation in wheat grains which can ultimately reduce the Zn malnutrition in human food chain.

Evaluation of nickel toxicity in wheat as function of diverse type of fertilizers: implications for public health

Many studies have described the physiological, biochemical, and molecular responses to heavy metal toxicity and deficiencies individually in plants. The present study assess nickel (Ni) concentration in amended soil, plant vegetative parts, and wheat grains, grown under diverse types of fertilizers in Sargodha, Punjab, Pakistan. Different varieties of wheat were grown in pot and fields. Different treatments (municipal solid waste, poultry waste, press mud, farm yard manure) of fertilizers were applied in order to study the metal level increased in different parts (root, shoot, grain) of wheat due to fertilization. Results indicated that metal level was found highest in roots followed by shoot and grain. The highest level of nickel in root was present in V1 (2.35 mg/kg) due to T2 (2.60 mg/kg) treatment. Higher nickel levels in wheat shoot and grains were observed in V5 (2.36 mg/kg) and V8 (2.29 mg/kg), respectively, due to applied treatment T2 (2.57 mg/kg). This study concluded that treatment T9 was proven safe in view of the observed Ni concentration, while treatment T2 (municipal solid waste) resulted in higher accumulation of nickel in wheat grains which showed that municipal solid waste should be treated before their application in agriculture fields to secure the public health. This study recommended that although application of fertilizers increased the plant growth and nutritional value, it also enhanced metal accumulation in the wheat grains which could be harmful for consumers especially human being. Government should take actions to prevent metal toxicity in human food chain.

Bioaccumulation and transfer of zinc in soil plant and animal system: a health risk assessment for the grazing animals

Heavy metals pollution has thorough worldwide apprehensions due to the instantaneous growth of industries. Farming regions are irrigated mainly with wastewater which contains both municipal and industrial emancipations. Keeping in view the above scenario, a study was designed in which three sites irrigated with ground, canal, and municipal wastewater in the District Jhang were selected to determine the zinc accumulation and its transfer in the soil, plant, and animal food chain. Zinc concentration was ranged as 18.85-35.59mg/kg in the soil, 26.42-42.67 mg/kg in the forage, and 0.982-2.85mg/kg in the animal samples. Investigated zinc concentration in soil and forages was found to be within the recommended WHO/FAO limits, but blood samples exceed the standards of NRC (2007). The maximum level of pollution load index (0.427-0.805mg/kg) and enrichment factor (0.373-0.894 mg/kg) for zinc was noticed upon wastewater irrigation. Daily intake (0.039 to 0.082 mg/kg/day) and health risk index (0.130 to 0.275 mg/kg/day) of zinc metal was higher in the buffaloes that feed on wastewater-irrigated forages. Bio-concentration factor (0.840 to 2.01mg/kg) for soil-forage was >1 which represents that these plants accumulated the zinc concentration into their tissues and raised health issues in grazing animals on consumption of wastewater-contaminated forages. As animal-derived products are part of human food, then zinc toxicity prevailed in livestock tissues ultimately affects the human food chain. Overall, findings of this study concluded that animal herds should be monitored periodically to devise preventive measures regarding the toxic level of heavy metals availability to livestock.

Ecological risk assessment of heavy metal chromium in a contaminated pastureland area in the Central Punjab, Pakistan: soils vs plants vs ruminants

Grazing animals act as a bioindicator to study the heavy metal status in the pasture lands because excessive amount of toxic metals in the animal diet either disturb their normal activity or deposit the contaminants into their tissues. The aim of this study was to appraise the chromium status in soil and pasture crops with respect to the nutritional requirement of grazing animals. Three different sites were selected to collect soil, forages, and animal samples from District Jhang. All the samples were processed through atomic absorption spectrophotometer to analyze the chromium concentration in them. Chromium concentration was varied as 0.703-4.20 mg/kg in soil, 0.45-2.85 mg/kg in forages, and 0.588-2.37 mg/kg in all collected animal samples. Both the soil and forage samples displayed the maximum chromium concentration in the Capparis decidua, whereas animal samples revealed maximum concentration in animal blood. Results of pollution load index (0.078 to 0.463 mg/kg) exhibited that all the sample values are less than unity while enrichment factor (1.57-8.25mg/kg) showed that significant level of chromium is enriched in these sites. The maximum value of daily intake (0.0007-0.0055mg/kg/day) and health risk index (0.0004-0.00370055mg/kg/day) was observed in the buffalo that feed on the Capparis decidua. Bio-concentration factor (0.398-2.09mg/kg) value was the maximum in the Medicago sativa. It is concluded that all the animal samples showed chromium concentration beyond their standards. Thus, proper measures should be taken to reduce the metal contamination in these areas that ultimately lessen the availability of toxic metals to grazing animals.

Increased sensitivity of heavy metal bioreporters in transporter deficient Synechocystis PCC6803 mutants

The detection and identification of heavy metal contaminants are becoming increasingly important as environmental pollution causes an ever-increasing health hazard in the last decades. Bacterial heavy metal reporters, which constitute an environmentally friendly and cheap approach, offer great help in this process. Although their application has great potential in the detection of heavy metal contamination, their sensitivity still needs to be improved. In this study, we describe a simple molecular biology approach to improve the sensitivity of bacterial heavy metal biosensors. The constructs are luxAB marker genes regulated by the promoters of heavy metal exporter genes. We constructed a mutant strain lacking the cluster of genes responsible for heavy metal transport and hence achieved increased intracellular heavy metal content of the Synechocystis PCC6803 cyanobacterium. Taking advantage of this increased intracellular heavy metal concentration the Ni²⁺; Co²⁺ and Zn²⁺ detection limits of the constructs were three to tenfold decreased compared to the sensitivity of the same constructs in the wild-type cyanobacterium.

Risk Assessment of Heavy Metals in Basmati Rice: Implications for Public Health

Basmati rice is increasingly recognized and consumed in different parts of the world due to its different tastes and nutritional properties. This research focused on determining the cadmium (Cd), cobalt (Co), Copper (Cu), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn) content in locally grown basmati rice in Pakistan and assessing the risks of these values to human health. Root, shoot and grain samples of basmati rice were taken, along with soil samples from the five regions studied. Metal mean concentrations (mg/kg) in grains fluctuated from 2.70 to 9.80 for Cd, 4.80 to 9.85 for Zn, 1.16 to 1.46 for Cu, 1.84 to 10.86 for Co, 2.05 to 13.07 for Fe, 5.03 to 11.11 for Mn and 3.24 to 13.28 for Ni, respectively. All metal values were within permissible limits except for Cd. The enrichment factor for Cd was highest among all sites. Cobalt and zinc had the highest bioaccumulation factor and translocation factor. The highest enrichment factor was noticed for Cd and the lowest for Cu. The health risk index at all examined sites was less than one. Consistent examination is recommended to limit health hazards instigated by the use of rice polluted with a greater concentration of Cd.

Blood, Hair and Feces as an Indicator of Environmental Exposure of Sheep, Cow and Buffalo to Cobalt: A Health Risk Perspectives

Exposure to toxic metals (TMs) such as cobalt (Co) can cause lifelong carcinogenic disorders and mutagenic outcomes. TMs enter ground water and rivers from human activity, anthropogenic contamination, and the ecological environment. The present study was conducted to evaluate the influence of sewage water irrigation on cobalt (Co) toxicity and bioaccumulation in a soil-plant environment and to assess the health risk of grazing livestock via forage consumption. Cobalt is a very necessary element for the growth of plants and animals; however, higher concentrations have toxic impacts. Measurement of Co in plant, soil and water samples was conducted via wet digestion method using an atomic absorption spectrophotometer. The Co pollution severity was examined in soil, forage crops (Sorghum bicolor Kuntze, Sesbania bispinosa (Jacq.) W. Wight, Cynodon dactylon (L.) Pers., Suaeda fruticosa (L.) Forssk. and Tribulus terrestris L.) in blood, hair and feces of sheep, cow and buffalo from district Toba-Tek-Singh, Punjab, Pakistan. Three sites were selected for investigation of Co level in soil and forage samples. Highest concentration of Co was 0.65 and 0.35 mg/kg occurring in S. bicolor at site I. The sheep blood, cow hair and sheep feces samples showed highest concentrations of 0.545, 0.549 and 0.548 mg/kg, respectively at site I and site II. Bioconcentration factor, pollution load index, enrichment factor and daily intake were found to be higher (0.667, 0.124, 0.12 and 0.0007 mg/kg) in soil, S. bicolor, S. fruticosa and in buffalo, respectively, at site I. It was concluded that forage species irrigated with wastewater are safe for consumption of livestock. However, though the general values were lower than the permissible maximum limit, it was observed that the bioaccumulation in the forage species was higher. Therefore, soil and food chain components should be avoided from trace metal contamination, and other means of nonconventional water resources should be employed for forages irrigation.

Monitoring of copper accumulation in water, soil, forage, and cows impacted by heavy automobiles in Sargodha, Pakistan

The instant endeavor was undertaken to monitor copper (Cu) contents in water, soil, forage, and cow's blood impacted by heavy automobiles in Sahiwal town of district Sargodha, Pakistan. The samples were collected in triplicates with a total of 120 soil and water samples with corresponding forage samples. For the analysis of metal concentration in cows, 60 blood samples were collected from the cows feeding on these forages on selected sites. Metal contents were analyzed by atomic absorption spectrophotometry. The results showed that water samples contained mean values of Cu concentration ranged from 1.01 to 0.444 mg/kg at all sites. It was maximum at site 3 and minimum at site 6. The soil samples of all the forage fields showed Cu mean values concentration ranged from 1.94 to 0.286 mg/kg at all sites. It was maximum in Trifolium alexandrinum grown field at site 2, and minimum in Avena sativa at site 2. All the forage samples showed the mean value of Cu concentration ranged from 0.151 to 1.86 mg/kg at all sites. The concentration of Cu was maximum in Zea mays grown at site 5 and minimum in Trifolium alexandrinum at site 4. The cow blood samples showed the mean concentration of Cu ranged from 1.368 to 0.53 mg/kg at all sites. It was maximum at site 2 and minimum at site 6. Owing to the results of pollution index and transfer factors, metal content was found to be in permissible range in forages as well as animal samples.

Evaluation of toxicity potential of cobalt in wheat irrigated with wastewater: health risk implications for public

The use of wastewater in irrigation weakens the beneficial properties of the soil and leads to a threat to food safety standards. The present research was designed to explore the cobalt toxicity associated with the ingestion of wastewater irrigated wheat. Wheat plants of five different varieties were collected from 7 different sites of Punjab, Pakistan, which were irrigated with three different sources of water. The sampling was done in two cropping years. The cobalt values in water, soil and wheat samples (root, shoot, grain) ranged from 0.46 to 1.24 mg/l, 0.15 to 1.20, 0.29 to 1.30, 0.08 to 0.76 and 0.12 to 0.57 mg/kg, respectively. All the water samples showed high cobalt concentration than the maximum permissible value. However, all the soil and wheat plant samples were found within the maximum allowable range. The high cobalt concentration in irrigating water showed that the continuous usage of such type of water may lead to cobalt toxicity in living organisms with the passage of time and may results in severe health risks.

Trace metal accumulation in pepper (Capsicum annuum L.) grown using organic fertilizers and health risk assessment from consumption

Organic farming and healthy nutrition are among the most popular topics of recent times. However, organic fertilizers, which are one of the important elements of organic agriculture, have the potential to threaten human health with the toxic substances they may contain. The present study aimed to observe the effect of farmyard manure, poultry waste and press mud on metal accumulation in pepper (Capsicum annuum L.) to determine the pollution severity of soil and to examine the health risk due to the consumption of organic fertilizer applied pepper. The multipurpose pot experiment was conducted to study the agronomical growth performance and accretion of metals in C. annuum grown with different organic fertilizers in the soil at the area of the Department of Botany, University of Sargodha, Pakistan. The trace metal contents in soil and C. annuum samples were analysed by atomic absorption spectrophotometer (AA-6300 Shimadzu Japan). Trace metal concentrations in soil samples ranged from 0.152 to 0.850, 2.167 to 5.812, 0.345 to 1.235, 2.682 to 5.875, 0.095 to 0.558, 6.132 to 17.062, 0.172 to 2.235 and 6.670 to 22.585 mg/kg for Cd, Co, Cr, Cu, Pb, Fe, Mn and Zn, respectively. In pepper samples, trace metal concentrations ranged from 0.364 to 2.206, 0.305 to 4.042, 0.272 to 1.160, 1.132 to 1.305, 0.164 to 0.204, 4.736 to 17.000, 0.844 to 1.150 and 14.751 to 18.385 mg/kg for Cd, Co, Cr, Cu, Pb, Fe, Mn and Zn, respectively. The accumulation of Cd and Pb had higher values of HRI than 1 and these values suggested that these metals had probability to cause health problems.

Effects of organic and chemical fertilizers on the growth, heavy metal/metalloid accumulation, and human health risk of wheat (Triticum aestivum L.)

The aim of this study was to determine and compare the effect of the chemical fertilizer and organic fertilizers such as cow manure and poultry manure applications on the heavy metal/metalloid accumulation in the wheat samples. A field experiment was conducted using a complete randomized block design with three replicates per treatment to observe the impact of organic and chemical fertilizers on the heavy metal/metalloid accumulation in a wheat variety (Lasani-08). Heavy metal/metalloid concentrations in the root, shoot, and grains of wheat samples were determined using an atomic absorption spectrophotometer (AAS). In addition, the growth parameters of wheat samples were assigned. Results indicated that morphological parameters showed maximum growth under chemical fertilizer treatment. The heavy metal/metalloid concentrations in the wheat grains ranged from 12.95 to 25.83, 1.03 to 1.11, 16.83 to 20.26, 0.92 to 0.98, 0.504 to 1.997, 2.24 to 5.98, and 0.493 to 1.154 mg/kg for Zn, Co, Fe, Cd, Pb, Cu, and Cr, respectively. All heavy metal/metalloid values in the present study were within the safe limits reported by the FAO/WHO except for Pb. However, the health risk index determined for all metals are higher in the wheat grown with chemical fertilizer applications, but it has been shown that the consumption of wheat grown with organic and chemical applications is not hazardous for health.

Effect of Organic Manure and Mineral Fertilizers on Bioaccumulation and Translocation of Trace Metals in Maize

Mineral fertilizers and organic manure are used as soil amender to enhance the mineral status of the soil. These fertilizers contain trace metals besides providing macro and micronutrients. The present study was performed to observe the effect of mineral fertilizers, poultry manure and cow manure on trace metal content of soil and various parts (root, shoot, and grains) of maize plant (Zea mays L.). The analysis of metals was performed by atomic absorption spectrophotometer (AA-6300 Shimadzu Japan). The highest level of Pb, Fe, Ni and Cu was observed in the root as 0.36-0.55, 70.41-83.03, 4.98-7.44 and 2.94-4.43 mg kg^- 1, respectively. The highest level of Cd, Zn and Mn was determined in grains as 0.44-1.59, 28.05-46.39 and 26.24-46.57 mg kg^- 1, respectively. The values of all metals were found within their permissible limit given by FAO/WHO except for the Cd. The interactive use of mineral and organic fertilizers enhanced the level of trace metals in maize as compared to their sole application. In the present findings, the health risk index for all metals was less than 1 in all treatments. So, it was concluded that the level of metals in poultry manure, cow manure and mineral fertilizer treated maize did not pose any potential threat to the consumers.

Trace Metal Accumulation in Trigonella foenum-graecum Irrigated with Wastewater and Human Health Risk of Metal Access Through the Consumption

The aim of the present research was to determine the trace metal accumulations in Trigonella foenum-graecum irrigated with three different water regimes (ground water, canal water and sugar mill water). Also, transfer factors, pollution load indices, and health risk indices were assessed to evaluate metal transport and accumulation through the food chain. The analysis was conducted by Atomic Absorption Spectrophotometer (Shimadzu model AA-6300) to evaluate the concentration of metals in water, soil and vegetables. Trace metal concentrations in water samples ranged from 0.84 to 1.67, 0.42 to 0.72, 0.45 to 0.85, 2.51 to 9.99, 1.21 to 1.92, 1.82 to 9.98 and 0.64 to 0.91 mg/kg for Cd, Cr, Cu, Fe, Ni, Zn and Mn, respectively. The mean metal concentrations in soil samples were determined as 0.25, 0.86, 0.96, 3.37, 0.4, 0.44 and 2.31 mg/kg for Cd, Cr, Cu, Fe, Ni, Zn and Mn, respectively. Trace metal accumulations in T. foenum-graecum samples gathered from where soil samples were taken are as follows: The contents of Cd, Cr, Cu, Fe, Ni, Zn and Mn ranged from 0.48 to 1.06, 0.11 to 0.35, 0.15 to 0.29, 1.43 to 8.39, 0.39 to 0.54, 2.1 to 3.05 and 0.42 to 0.47 mg/kg, respectively. Statistical analyses showed that the treatments have non-significant effect (p > 0.05) on concentrations of metals in T. foenum-graecum samples collected from three sites for Ni, Cr, Cu, Zn and Mn and significant effect on Fe and Cd.

Potential Use of Biochar from Various Waste Biomass as Biosorbent in Co(II) Removal Processes

The removal of Co(II) ions from aqueous media was done using three types of biochars obtained from algae waste biomass, mustard waste biomass, and soy waste biomass. The biochar samples were obtained by pyrolysis of waste biomass resulted from biofules production, at relative low temperature (600–650 °C), and this procedure can be considered a suitable alternative to reduce the volume of such waste. FTIR spectra recorded for each type of biochar reveal the presence of several functional groups that can be used as binding sites for Co(II) retention. The batch biosorption experiments were performed as a function of initial Co(II) ions concentration and contact time, at constant solution pH (5.0), sorbent dose (8.0 g/L), and room temperature (25 ± 1 °C). The sorption experiments showed that the Co(II) ions retention reaches the equilibrium in maximum 60 min, and the maximum sorption capacity follows the order: Mustard biochar (MBC—24.21 mg/g) < soy biochar (SBC—19.61 mg/g) < algae biochar (ABC—11.90 mg/g). The modeling of experimental data proves that the retention of Co(II) ions from aqueous solution occurs through electrostatic interactions, and that the sorption process takes place until a monolayer coverage is formed on the outer surface of the biochar. This information is very useful in the design of a suitable desorption system. The desorption results showed that by treating the biochar samples loaded with Co(II) ions with 0.1 mol/L HNO3 solution, over 92% of Co(II) ions are desorbed and can be recovered, and the biochar samples can be used in at least three sorption/desorption cycles. All the experimental observations sustain the potential use of biochar obtained from different types of waste biomass as a promising alternative sorbent for the removal of Co(II) ions from aqueous media.