Journal of trace elements and minerals最新文献

Background

Artisanal gold mining can help reduce poverty while creating job possibilities for many low-income and unskilled workers. However, it is an activity with several detrimental societal consequences. Miners are exposed to chemical toxins that have long-term health consequences.

Objectives

This study examined soil degradation, pollution, and environmental hazards from artisanal gold mining in Ibodi-Ijesa, Osun State, Nigeria. The aim is to assess the levels of Cu, Co, Cd, Pb, As, and Ni in the study area as potential indicators of environmental concerns.

Methods

Soil samples were systematically collected from 66 distinct locations surrounding the gold mining site, at depths ranging from 0 to 15 cm, within distances of 0 to 500 m, and at intervals of 100 m. These samples underwent standard laboratory procedures for heavy metal analysis using Atomic Absorption Spectroscopy (AAS).

Results: The findings showed that copper (Cu), cobalt (Co), lead (Pb), and nickel (Ni) concentrations ranged from 80.17 to 100.11 mg.kg⁻¹, 42.11 to 50.07 mg.kg⁻¹, 30.93 to 54.00 mg.kg⁻¹, and 35.30 to 44.20 mg.kg⁻¹, respectively. Nickel (Ni), cadmium (Cd), and arsenic (As) were all below the detection limit. Although all analysed heavy metal concentrations were lower than the control samples, they outperformed the control values. The contamination index showed no distinct distribution pattern, but all values surpassed those of the control samples. Furthermore, the Health Risk Index was greater than one, indicating possible health hazards for inhabitants.

Conclusion

The study indicated that artisanal gold mining operations in Ibodi-Ijesa substantially influenced soil quality, raising heavy metal concentrations and posing health hazards to adjacent populations.

Cadmium is a non-essential trace metal element with no known biological function. Cd is toxic to both plants and human beings; hence, it is of prime concern to the scientific community. The objective of this research is to find out the effect of heme oxygenase 1 on Cd toxicity in Sorghum bicolor seedlings. Hydroponically adapted seedlings were treated to various concentrations of Cd within the range of 10 to 200 μM. Seedlings were harvested after 120 h of Cd stress. The cellular homeostasis and metal tolerance mechanisms were conducted to evaluate growth parameters, stress parameters (MDA and H₂O₂ content), non-enzymatic and enzymatic parameters (CAT, APX and GPX) including HO 1. The results showed that HO 1 activity was measured to be highest in leaves at 150 μM CdCl₂, which was 29.61 %.The HO 1 activity was correlated with the MDA content and antioxidant enzymes activity at this Cd concentration. The highest activity of HO 1 was revealed through the decrease of GPX and CAT activities. Consequently, HO 1 works within a cohort that helps the development of the plant's defense mechanisms by scavenging ROS, which is confirmed by the time-dependent study. Accordingly, our research highlighted that HO 1 might increase the efficiency of stress tolerance by enhancing antioxidant defence mechanisms against Cd toxicity in S. bicolor.

Background

Trace metal deficiency has become a major constraint on the productivity and sustainability of soils. Agriculture becomes more complex, advanced and intensive farming systems develop, however, the deficiency of trace metal are more frequent and extensive in different systems.

Methods

This study investigated the variation of trace metal minerals in soil profiles of diverse land use systems (LUSs), i.e. agriculture, horticulture and forestry, falling under three dominant soil orders (Entisol, Inceptisol and Aridisol) in Malwa region of Punjab. Through comprehensive analyses, we explore the intricate relationships between soil characteristics, land use practices, and the distribution of key trace metals—namely zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn).

Results

The mean values of DTPA-extractable trace metal from soil profiles of different land uses varied from 1.75 to 2.09, 1.64–2.32, 1.18–1.69 mg kg⁻¹ for Zn; 0.59–1.02, 0.59–0.99, 0.64–0.92 mg kg⁻¹ for Cu; 12.12–16.49, 9.84–16.05, 7.94–11.56 mg kg⁻¹ for Fe; 7.82–9.99, 4.66–9.39, 6.51–7.46 mg kg⁻¹for Mn in soil orders Entisol, Inceptisol and Aridisol, respectively. The concentration of trace metals in different soil orders follows the pattern of ntisol>Inceptisol>Aridisol. In contrast, there is a considerable amount of variation and no discernible pattern in the distribution of trace metals under various LUSs in each soil order. Several LUSs were examined, and agriculture land use system (ALUS) had the greatest Fe and Mn content, while the horticulture land use system (HLUS) had the highest Zn and Cu content. The Irrespective of soil orders and LUSs, the concentration of trace metals decreased as soil depth increased. Diverse LUSs and management practices have a substantial impact on the physico-chemical characteristics of soils, which in turn influence the availability of trace metals. According to the Pearson correlation studies, trace metals were positively associated with soil OC and negatively associated with soil pH, electrical conductivity (EC), and calcium carbonate (CaCO₃) and there was also a positive correlation between DTPA-Zn, Cu, Fe, and Mn in the investigated soils. The results of the principal component analysis (PCA) revealed that soil CaCO₃ and organic carbon (OC) content were the most variable soil parameters influencing crop trace metal availability in different soil orders and land use systems.

Conclusion

The findings contribute to a nuanced understanding of the dynamic interplay between soil properties and land use, providing valuable insights for sustainable agricultural practices and environmental management in the region.

Background

Ambergris is a coprolith produced by some sperm whales (∼1 %). It has been hypothesised that the metals in ambergris derive from the haemolymph of squid in the whale diet (mainly copper). However, few data exist.

We report analysis of 10 trace metals in each of 50 ambergris samples by inductively coupled plasma-mass spectrometry.

Main Findings

Acid digests of the samples contained ∼5 to >6880 µg g⁻¹ air-dried weight total metals; mainly of iron (present in ∼90 % of samples, 38), copper (∼95 % of samples, 40), zinc (93 % of samples, 39) and cadmium (∼95 % of samples, 40).

Conclusions

We suggest the variable and sometimes high concentrations of iron may reflect traces of haemoglobin or myoglobin from the whales. There may be other sources.

The other major metals (Zn, Cu, Cd) are those also reported in several squid species. The distributions are unlike those of squid haemolymph alone, reportedly dominated by copper, or those of the sperm whale (e.g., skin), dominated by zinc.

Background/Introduction

This study seeks to determine health risk associated with consumption of

clay in different areas in southern Nigeria.

Methods

Different clay samples sold for consumption were purchased from Mowe, Ikorodu and Onitsha Markets in southern Nigeria. The clays were subjected to mineralogical and geochemical characterization using X-Ray Diffractometry (XRD), Fourier Transform Infrared (FTIR) and Inductively Coupled Plasma-Atomic Emission Spectrometry. Potential health risk assessment was calculated using a standardized Hazard Quotient (HQ) and Total Hazard Index (THI).

Results

XRD and FTIR results revealed the clay contains varying percentage of quartz, kaolinite, anatase, halite, pyrite, goethite, smectite and palygorskite while geochemical analysis result revealed wide range of elemental concentration (ppm). Mean concentration (ppm) of Cu, Pb, Zn, Cr, Ni and Co from the markets are 5.8 – 8; 17.4 – 29.6; 32.4 – 95.8;111.6 – 103.4; 18.6 – 39.4 and 4 – 16.6 respectively while As was below detection limit in most of the samples. HQ values were used to calculate the THI. THI values for children and adults for Mowe market samples range from 0.9-2.1 and 0.5-1.1 respectively, for Ikorodu market samples, THI for children and adult ranges from 1.0- 1.8 and 0.6-1.0 respectively, while THI for children and adults for Onitsha market samples ranges from 1.5-2.6 and 0.8-1.84 respectively.

Conclusion

In conclusion, children that consume clay from the markets are more exposed to non-carcinogenic risks than adults. It is therefore advisable that the clays should not be consumed for a long period of time to avoid health problems.

Introduction

Bread, a staple food consumed by a large portion of the population worldwide, including Nigeria, has emerged as one of the most popular quick meal options. The excessive intake of potassium bromate and trace metals in bread has been identified as detrimental to human health due to its heightened propensity to induce cancer in human.

Objective

The current study assessed the exposure to potassium bromate (KBrO₃) and trace metals through bread consumption, as well as the associated risks to dietary habits among Ado Ekiti, Southwest Nigeria residents. Bread varieties commonly consumed in Ado Ekiti were randomly chosen from local bakeries. These bread samples were then analyzed in the laboratory using an Atomic Absorption Spectrophotometer to determine the levels of trace metals, including lead (Pb), manganese (Mn), nickel (Ni), chromium (Cr), zinc (Zn), cadmium (Cd), and cobalt (Co), as well as potassium bromate concentrations.

Results

The findings revealed that cobalt (Co) had the highest mean concentration (29.35±3.59 mg.kg⁻¹), whereas lead (Pb) exhibited the lowest mean concentration (0.06±0.02 mg.kg⁻¹). The sequence of trace metal levels was Co > Cd > Zn > Ni > Mn > Cr > Pb. All trace metal concentrations exceeded the standards set by FAO/WHO. Regarding potassium bromate content, it ranged from 0.01 mg.kg⁻¹ to 0.06 mg.kg⁻¹, surpassing the maximum permissible limits of 0.02 mg.kg⁻¹ set by the Food and Drug Administration.

Although the chronic hazard quotient among adults and children was low, the hazard ratio ranged from 11 to 9 among adults and from 14 to 9 among children, suggesting the potential for carcinogenic effects with repeated consumption. Based on the hazard ratios, the estimated chances of developing cancer from daily consumption of bread samples were approximately 14 in 1,000,000, 86 in 1,000,000, 71 in 1,000,000, and 40 in 1,000,000, respectively, for the adult population, and about 20 in 1,000,000, 11 in 1,000,000, 90 in 1,000,000, and 56 in 1,000,000 for the children population.

Conclusion

The study showed that trace metals Pb, Mn, Ni, Cr, Zn, Cd and Co concentrations were higher than the FAO/WHO permissible limits. The concentration of potassium bromate in all the sorted bread samples exceeded the maximum acceptable limits except one. Though chronic hazard quotient among adults and children was low, the hazard ratio among the adult and children population was high, signifying possible cancer risks when continually consumed. These findings underscore the importance of stringent oversight by Nigerian regulatory authorities over using potassium bromate as an ingredient in bakeries.

Introduction

Trace metals in fish play different important roles, both for the fish itself and humans who consume them. However, some of these metals are toxic at low concentrations, and are considered as health hazards. In this study, the concentration of six trace metals (Pb, Cd, Ni, Cu, Mn and Zn) were determined in imported frozen fish species available in Bayelsa State, Nigeria. The effect of domestic heat processing techniques (cooking, frying and smoking) on the trace metals concentration, and the potential risk due to consumption of these metals in fish were also evaluated.

Methods

Six different species of imported frozen fish species were purchased from wholesale and retail outlets, and were prepared as raw, cooked, fried and smoked samples. A mixture of acids was used for digestion of fish samples, while Flame atomic absorption spectrometer was used for quantification of metals. The hazard index was employed for evaluating the non-carcinogenic risk of metals in fish.

Results

The average trace metals concentration in the raw fish samples followed the order: Zn > Cu > Cd > Ni > Mn. Pb was undetected in all fish samples. The concentration of the detected trace metals ranged as follows - Cd: 3.45–9.40 mg/kg, Ni: <0.001–13.13 mg/kg, Cu: 6.10–9.95 mg/kg, Mn: <0.001–1.05 mg/kg, and Zn: 14.50–43.65 mg/kg. The Cd concentration in all raw fish species greatly exceeded its permissible limits. The effect of domestic heat processing techniques on trace metals concentration in fish did not follow any regular pattern, and only Cd concentrations exceeded its permissible limit in all heat processed fish samples. The hazard quotient (HQ) values showed that only Cd had HQ values >1 for both child and adult exposure scenarios.

Conclusion

The results suggest trace metal contamination of fish samples by Cd, with significant potential non-carcinogenic risk. Since Cd is toxic, continuous screening of imported fish products is necessary, in order to safeguard public health.