Assessment of potentially toxic elements (PTEs) concentrations in Maize as an animal feed in Tehran, Iran

Maize (Zea mays L.) is a popular livestock feed as well as a good accumulator of toxic elements. Considering the potential for toxic elements to transfer from animal feed to human body through the food chain, along with the carcinogenic characteristics of these elements, the current study aims to evaluate the concentrations of cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) in 141 samples of Maize collected from Tehran, Iran.The concentrations of potentially toxic elements were measured using Atomic Absorption Spectrophotometry. The mean levels of toxic elements including Cd, Pb, As, and Hg in maize samples were 0.009±0.007 ppm, 0.090±0.034 ppm, 0.013±0.006 ppm, and 0.009±0.002 ppm, respectively.Our findings indicate that the mean concentrations of toxic elements in all samples were significantly (P ≤ 0.001) lower than the recommended levels set by Iranian standard organization (ISO). Therefore, maize consumed, as an animal staple feedstuff, is safe in terms of toxic element concentrations. Considering the novelty of this study, as the number of the studies in this field is limited in Iran and the significance of this research, is highlighted by the wide distribution of toxic elements in the surrounding environment and their inevitable entrance to feedstuffs as well as their accumulative behavior, continuous monitoring is highly recommended to ensure consumer safety

Concentration ciguatoxins in fillet of fish: A global systematic review and meta-analysis

In the current study, an attempt was made to meta-analyze and discuss the concentration of ciguatoxins (CTXs) in fillets of fish based on country and water resources subgroups. The search was conducted in Scopus and PubMed, Embase and Web of Science to retrieve papers about the concentration of CTXs in fillet fish until July 2022. Meta-analysis concentration of CTXs was conducted based on countries and water resources subgroups in the random effects model (REM). The sort of countries based on the pooled concentration of CTXs was Kiribati (3.904 μg/kg) > Vietnam (1.880 μg/kg) > Macaronesia (1.400 μg/kg) > French (1.261 μg/kg) > China (0.674 μg/kg) > Japan (0.572 μg/kg) > USA (0.463 μg/kg) > Spain (0.224 μg/kg) > UK (0.170 μg/kg) > Fiji (0.162 μg/kg) > Mexico (0.150 μg/kg) > Australia (0.138 μg/kg) > Portugal (0.011 μg/kg). CTXs concentrations in all countries are higher than the safe limits of CTX1C (0.1 μg/kg). However, based on the safe limits of CTX1P, the concentrations of CTXs in just Portugal meet the regulation level (0.01 μg/kg). The minimum and maximum concentrations of CTXs were as observed in Selvagens Islands (0.011 μg/kg) and St Barthelemy (7.875 μg/kg) respectively. CTXs concentrations in all water resources are higher than safe limits of CTX1C (0.1 μg/kg) and CTX1B (0.01 μg/kg). Therefore, it is recommended to carry out continuous control pans of CTXs concentration in fish in different countries and water sources

Assessment of the toxicity and the fertilizing power from application of gamma irradiated anaerobic sludge as fertilizer: Effect on Vicia faba growth

With increasing sludge produced every day by wastewater treatment plants, new methodologies have been developed to reduce sludge or to valorize them at lower cost and energy. Among these methodologies, agricultural manuring is of great interest as sludge could complement or replace chemical fertilizers. However, sludge pretreatment was necessary prior to its use in order to eliminate the degradable organic contaminants, heavy metals and diverse pathogenic microorganisms. In this study we performed γ-irradiation of anaerobic sludge coming from wastewater treatment plants at different doses (0.5, 1.5, 2.5, 3.5 and 4.5 kGy), followed by anaerobic digestion. We then used them in addition to soil for Vicia faba cultures. Heavy metal concentrations, toxicological evaluations, and the number of cultivable pathogenic bacteria were also investigated in irradiated and non-irradiated sludge samples to determine the effect of γ-irradiation on toxicity and pathogens present in the sludge. Results show that 4.5 kGy is the optimal dose, and γ-irradiation pretreatment of anaerobic sludge added to soil (2 mL/30 g) has significantly improved Vicia faba growth. Furthermore, by eliminating pathogens and by degrading chemical pollutants, γ-irradiation of anaerobic sludge provides promising insights for re-using sludge as a safe fertilizer