A total of 549 samples of rice, maize, wheat, sorghum and millet were obtained from markets in Ghana, the EU, US and Asia. Analysis of the samples, originating from 21 countries in 5 continents, helped to establish global mean trace element concentrations in grains; thus placing the Ghanaian data within a global context. Ghanaian rice was generally low in potentially toxic elements, but high in essential nutrient elements. Arsenic concentrations in rice from US (0.22 mg/kg) and Thailand (0.15 mg/kg) were higher than in Ghanaian rice (0.11 mg/kg). Percentage inorganic arsenic content of the latter (83%) was, however, higher than for US (42%) and Thai rice (67%). Total arsenic concentration in Ghanaian maize, sorghum and millet samples (0.01 mg/kg) was an order of magnitude lower than in Ghanaian rice, indicating that a shift from rice-centric to multigrain diets could help reduce health risks posed by dietary exposure to inorganic As.

The foliar application of selenium (Se) is an effective method for biofortification of Se in crop grains in order to provide sufficient Se for human health. As a staple food in China, the foxtail millet (Setaria italica L.), which had been Se biofortification, would be helpful to overcome Se deficiency in the diet. The Se fertilizer and its application technology are vital for reducing environmental risk while enriching selenium. Hence, the Se-rich nutrient solution developed by ourselves was used, and the effect of its amount and growth stage applied on the accumulation of Se in grains of foxtail millet (Setaria italica L.) was studied in the present study. The results were as follows: (1) the Se concentration in grains increased with the Se application rate increasing, and the highest Se concentration in grains was 1.83 mg kg⁻¹ at the sprayed concentration of 61.5 gSe hm⁻²; (2) the accumulation of Se sprayed in the grain-filling stage was 1.3–1.6 times higher than that in the joint stage; and (3) the organ damage could be found under low Se/S ratio, which happened in the rice leaves when the Se rate was higher than 76.875 gSe m⁻² with the low sulfate application compared with the formulation. This Se-rich nutrient solution could be used to produce the Se-rich millet grains and foliar application in the reproductive stage to produce qualified Se-rich millet.

The collapse of the Fundão dam in Mariana, MG, in 2015 resulted in the overflow of more than 50 million m³ of mud containing mine tailings, leaving a path of destruction and immeasurable social and environmental consequences. Tailings’ chemical and physical assessments revealed the presence of some elements at levels higher than those allowed by Brazilian guidelines. The tailings also showed high density, which restricts vegetation recovery. Therefore, this study aimed to analyze the effects of mud containing mine tailings from the Fundão dam on the germination and initial growth and development of three plant species: millet, maize, and sorghum. These species were cultivated on substrates with five tailings proportions: 0 T (100% sand), 25 T (25% tailings + 75% sand); 50 T (50% tailings + 50% sand); 75 T (75% tailings + 25% sand); and 100 T (100% tailings). In experiment I, the germination and initial growth of seedlings (plants with 1 or none fully expanded leaf) in these substrates were evaluated. In experiment II, growth parameters, photosynthetic efficiency (gas exchange and chlorophyll a fluorescence), metal accumulation, and plant root morphology of the same species were evaluated at the three fully expanded leaves vegetative stage (V3). Overall, the germination of seedlings and the initial growth of the three species analyzed were not affected by the presence of tailings. However, in plants at the V3 stage, morphophysiology variations differed among species, given that their growth, biomass accumulation, and root dynamics were altered. Proportions of tailings in the substrate did not influence the absorption of iron or manganese by the studied plants. At the V3 stage, maize was the most tolerant, with a more robust root system, and showed fewer morphological changes and greater water use efficiency than the other studied species.

The utilization of agricultural wastes is an attractive and viable option to reduce the environmental pollution and reverse the over-exploitation of fossil fuels. Now-a-days, the usage of fossil fuels has increased manifold causing twin serious problems such as depletion of limited source of fossil fuels and increase in environmental pollution with major consequences. In this study, briquettes were produced using sorghum panicles (SP) and pearl millet (PM) with different ratios (100:0, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10 and 0:100) using cassava starch as a binder with a planned compacting pressure level (200 kN) by exploring hydraulic compression method. The proximate parameters such as water content, level of fixed carbon, ash and volatile matter were determined using American Society for Testing and Materials (ASTM) standard procedures. The elemental analyses (SEM/EDAX) which include carbon (C), oxygen (O), potassium (K), calcium (Ca), chlorine (Cl), sulphur (S), phosphorus (P), aluminium (Al), silicon (Si), magnesium (Mg), cobalt (Co), iron (Fe), zinc (Zn) and sodium (K) were determined in all the briquette samples. Weight loss and optimum heating values of the samples were measured by adopting differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. In addition to that, the density and compressive strength of all the produced briquettes were determined. In comparison with pongamia–tamarind shell, sorghum panicle–pearl millet briquettes have better fuel properties. The pongamia–tamarind shell fuel has nitrogen and hydrogen whereas sorghum panicle–pearl millet has no identities on both nitrogen and hydrogen content. The occurrence of nitrogen absence is due to non-availability of NOx emissions during combustion. By the cause of more fixed carbon composition, there exists lack in hydrogen content. The sorghum panicle–pearl millet briquettes have better calorific value than pongamia–tamarind shells, and they produce better heating values. Hence, the prepared biomass briquettes are potentially good fuels that derived from agro wastes. Likewise, the determined parameters are compared with the other biomass briquettes.

The gamma spectrometric analysis of soil and essential foodstuffs, e.g., wheat, millet, potato, lentils and cauliflower, which form the main component of the daily diet of the local public, was carried out using high purity germanium (HpGe) detector coupled with a computer based high-resolution multi-channel analyzer. The activity concentration in soil samples for ²²⁶Ra, ²³²Th and ⁴⁰K ranged from 30.0 Bq kg⁻¹ to 81.2 Bq kg⁻¹, 31.4 Bq kg⁻¹ to 78.25 Bq kg⁻¹ and 308.8 Bq kg⁻¹ to 2177.6 Bq kg⁻¹, with mean values of 56.2, 58.5 and 851.9 Bq kg⁻¹, respectively. The average activity measured for ²²⁶Ra, ²³²Th and ⁴⁰K in soil samples was found higher than the world average. The major radionuclide found in the food items studied was ⁴⁰K, while ²²⁶Ra, ²³²Th and ¹³⁷Cs were detected in very nominal amounts. The results clearly indicate that these radionuclides have no health hazard to human beings, as they are well below the annual limit of intake (ALI) for these radionuclides. The transfer factors of these radionuclides from soil to food were also studied. The mean transfer factors of ⁴⁰K, ²²⁶Ra, ²³²Th and ¹³⁷Cs from soil to food were estimated to be about 0.17, 0.07, 0.16 and 0.23, respectively. An artificial radionuclide, ¹³⁷Cs, was also present in detectable amount in all samples. The internal and external hazard indices were measured and had mean values of 0.70 and 0.55, respectively. Absorbed dose rates and effective dose have been determined in the present study. Concentration of trace metals, such as Cr, Pb, Ni and Zn, was also determined in the soil samples. The concentrations of radionuclides and trace metals found in these samples during the present study were nominal and do not pose any potential health hazard to the general public.

In the present study, the outcome of sewage, canal, and ground water on the chromium (Cr) concentration in corn and ultimately in chicken body parts was reported. To evaluate Cr level, atomic absorption spectrophotometer (Flame Atomic Absorption Spectrophotometer AA 6300, Shimadzu Japan) was used. The highest level of Cr in grains (0.50 ± 0.05 mg/kg), shoots (0.90 ± 0.01 mg/kg), and roots (1.01 ± 0.02 mg/kg) were noticed in the Sadaf variety watered with canal water. The least concentration of Cr was recorded in grains (0.07 ± 0.01 mg/kg), shoots (0.59 ± 0.01 mg/kg), and roots (0.71 ± 0.01 mg/kg) of Pearl variety irrigated with ground water. The maximum concentration of chromium in the blood (1.68 ± 0.02 mg/kg) and bones (1.26 ± 0.24 mg/kg) was observed in chicks fed on Millet Research Institute (MMRI) grains reared with the sewage water. The lowest concentration was observed in the blood (1.60 ± 0.04 mg/kg) and in bone (0.80 ± 0.01 mg/kg) of the chicks fed Pearl variety grains reared with canal water. In the second experiment, the maximum content of Cr was determined in the blood (0.74 ± 0.04 mg/kg) and bones (1.76 ± 0.02 ppm) of chicks consuming Sadaf variety grains reared with canal water and the least concentration in the blood (0.26 ± 0.03 mg/kg) and bones (1.64 ± 0.01 mg/kg) was determined on the consumption of the Pearl variety grains reared with ground water. A similar trend was observed in other body organs. It was concluded that polluted water causes higher accumulation levels of Cr in plant parts and even in animals’ body parts after the utilization of such plants.

The equilibrium of the structure and functioning of freshwater ecosystems is dependent of detritivores that link all the other functional groups. The preference for feeding leaves with different diameters (particle size) and leaves with metal contamination (several concentrations of the essential metals copper and zinc) were determined for two detritivores, the decapod Atyaephyra desmarestii and the amphipod Echinogammarus meridionalis. Several no-choice and multi-choice assays were done to determinate which leaf diameter the amphipod and the decapod species would eat when they had or not had alternatives available and include a set of dual-choice assays with contaminated and uncontaminated foods. No significant preference was shown by either species relative to the diameter of leaves, either on no-choice or multi-choice assays. The presence of essential metals on food did not had any influence on the feeding choice of these organisms over the concentration range studied. Both showed no preference on ingesting food spiked with these essential metals, except E. meridionalis which preferred ingesting leaves with 2.19 μg.l⁻¹ of copper instead of uncontaminated leaves. For further works, despite no preference for leaves with a certain diameter, the leaves with 0.70 cm (0.385 cm²of area) and with 0.50 cm (1.767 cm² of area) should be used for A. desmarestii and E. meridionalis, respectively. Furthermore, to maintain E. meridionalis, the diet should include some percentage of copper in order to accomplish metabolic needs.