Transfer of Heavy Metals from Different Sources of Fertilizers in Wheat Variety (Galaxy-13)

Evaluation of the Effects of Wastewater Irrigation on Heavy Metal Accumulation in Vegetables and Human Health in the Cauliflower Example : Heavy Metal Accumulation in Cauliflower

The goals of the present research were to determine the heavy metal contents in the water-soil-cauliflower samples in industrial wastewater irrigated areas and to assess the health risks of these metals to the people. Metal analyses were carried out using the atomic absorption spectrophotometer equipped with a graphite furnace. The metal readings in the cauliflower specimens ranged from 1.153 to 1.389, 0.037 to 0.095, 0.61 to 0.892, 0.625 to 0.921, 1.165 to 2.399, 0.561 to 0.652, 0.565 to 0.585, 0.159 to 0.218 and 1.268 to 1.816 mg/kg for Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn and Mn, respectively. Statistics revealed that, with the exception of Pb and Co (p > 0.05), there was no statistically significant variation in the metal concentrations in the cauliflower samples according to the irrigation type. Pb, Ni, and Cr had HRI values below 1.0 and did not seem to be a hazard to human health, in contrast to Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn and Mn, which glanced to constitute a health risk. Regular monitoring of vegetables irrigated with wastewater is strongly advised to reduce health hazards to people.

Arsenic Levels and Seasonal Variation in Pasture Soil, Forage and Horse Blood Plasma in Central Punjab, Pakistan

The present study aimed to determine the accumulation levels of arsenic in pasture soil, forage and animals. An atomic absorption spectrophotometer was used to determine the concentration of metals in the samples of soil, forage and blood plasma of horses. The level of arsenic ranged between 4.26 mg/kg (summer) and 4.66 mg/kg (winter) in soil samples and 2.67 mg/kg (summer) and 2.94 mg/kg (winter) in forage samples. In blood plasma samples, the mean arsenic (As) values varied between 1.38 and 1.52 mg/L. In the blood plasma samples, the mean As values varied between 1.38 and 1.52 mg/L. No statistically significant changes were observed for arsenic concentrations in plasma samples of horses for sampling seasons (p > 0.05). A positive correlation was observed for forage and blood plasma to a certain degree for arsenic but for other media, arsenic correlations were negative and insignificant. It is therefore suggested that regular monitoring of heavy metals in soils/plants/animals is essential to prevent excessive build-up of arsenic.

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.

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.

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.

Silicon Application Modulates Growth, Physio-Chemicals, and Antioxidants in Wheat (Triticum aestivum L.) Exposed to Different Cadmium Regimes

Silicon (Si) application enhanced the tolerance of plants against different environmental stresses. Therefore, objective of the study revealed that foliar applied Si alleviates the adverse effect of Cd by enhancing the growth, metabolite accumulation, strengthening the antioxidant defense system, reducing oxidative injury, improving plant nutrient status, and decreasing the Cd uptake in wheat. The surface sterilized seeds of Sahar-2006 (tolerant) and Inqalab-91 (sensitive) having the differential metal tolerance capacity were sown in plastic pots containing normal and Cd spiked sandy loamy soil. The design of experiments was completely randomized with 3 replicates per treatment. Two weeks after germination, plants were sprayed with different concentrations of Si (1.5 and 3 mM) with 0.1% surfactant in the form of Tween-20. The plants were harvested after 2 weeks of Si application to determine various attributes. High concentration of Cd (25 mg kg-1) decreased growth-related-attributes, essential nutrient uptake and increase the levels of oxidative stress indicators. The application of Si increased the growth-related attributes, photosynthetic pigments, essential nutrient uptake and also enhanced the activities of various antioxidant compounds (superoxide dismutase (SOD), peroxidase (POD, ascorbate peroxidase (APX) and catalase (CAT) by decreasing the contents of oxidative stress indicators and Cd uptake in root and shoot of both wheat cultivars. Sahar-2006 cultivar showed more tolerance to Cd regimes than that of Inqalab-91 as clear from greater plant dry masses. Thus, our results showed that the applied Si level (3 mM) is an efficient strategy for field use in the areas, where slightly Cd polluted soils limit the agriculture production.

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.

Heavy metal induced stress on wheat: phytotoxicity and microbiological management

Among many soil problems, heavy metal accumulation is one of the major agronomic challenges that has seriously threatened food safety. Due to these problems, soil biologists/agronomists in recent times have also raised concerns over heavy metal pollution, which indeed are unpleasantly affecting agro-ecosystems and crop production. The toxic heavy metals once deposited beyond certain permissible limits, obnoxiously affect the density, composition and physiological activities of microbiota, dynamics and fertility of soil leading eventually to reduction in wheat production and via food chain, human and animal health. Therefore, the metal induced phytotoxicity problems warrant urgent and immediate attention so that the physiological activities of microbes, nutrient pool of soils and concurrently the production of wheat are preserved and maintained in a constantly deteriorating environment. To mitigate the magnitude of metal induced changes, certain microorganisms have been identified, especially those belonging to the plant growth promoting rhizobacteria (PGPR) group endowed with the distinctive property of heavy metal tolerance and exhibiting unique plant growth promoting potentials. When applied, such metal-tolerant PGPR have shown variable positive impact on wheat production, even in soils contaminated with metals, by supplying macro and micro nutrients and secreting active biomolecules like EPS, melanins and metallothionein (MTs). Despite some reports here and there, the phytotoxicity of metals to wheat and how wheat production in metal-stressed soil can be enhanced is poorly explained. Thus, an attempt is made in this review to better understand the mechanistic basis of metal toxicity to wheat, and how such phytotoxicity can be mitigated by incorporating microbiological remediation strategies in wheat cultivation practices. The information provided here is likely to benefit wheat growers and consequently optimize wheat production inexpensively under stressed soils.

Among many soil problems, heavy metal accumulation is one of the major agronomic challenges that has seriously threatened food safety.