Journal of trace elements and minerals最新文献

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.

Context

Given the global significance of wheat production and consumption, it is imperative to achieve high yields of nutritious wheat grains. However, the inadequate availability of zinc (Zn) in salt-affected soils can aggravate salt stress, decrease wheat grain yield, and grain Zn concentration. This study compared the effectiveness of soil Zn application and seed Zn priming in increasing Zn biofortification and grain yield of Zn-biofortified wheat grown in alkaline-calcareous soil affected by salts.

Methods

Eighteen pots were filled with alkaline-calcareous soil containing elevated levels of soluble salts and exchangeable sodium (Na). The pots were subjected to soil Zn application (0 or 8 mg kg⁻¹) and seed priming (control/non-, hydro-, or Zn-primed seeds) treatments, applied to a Zn-biofortified wheat (cv. Zincol-2016). Plant samples were collected at the heading and maturity stages to measure parameters related to plant growth and grain quality.

Findings

Soil Zn application increased grain and straw yields across seed priming treatments by a maximum of 23 %, and seed Zn priming increased grain and straw yields across soil Zn rates by a maximum of 21 %. This yield response was accompanied by significant increases in grain potassium and Zn concentrations at maturity, as well as non-significant to significant increases in photosynthetic parameters (stomatal conductance, photosynthetic rate and transpiration rate) in flag leaves during heading. Additionally, compared to control, the combined treatment of soil Zn application and seed Zn priming decreased grain Na concentration by 14 %. Compared to control, both soil Zn application and seed Zn priming significantly increased grain Zn concentration. With the combined application treatment, the grain Zn concentration reached 27 mg kg⁻¹, but it remained significantly below the desired level of >37 mg kg⁻¹. Seed Zn priming decreased the phytate-to-Zn molar ratio in grains, while the treatments that received soil Zn application exhibited the lowest values of this ratio, potentially increasing Zn bioavailability to humans.

Conclusions

The findings suggest that soil Zn application is more effective in enhancing grain yield and Zn concentration, while seed Zn priming remains crucial in low-Zn and high-salt soils. Future research should optimize Zn application strategies for Zn-biofortified wheat cultivated in salt-affected fields.

Introduction

The Niger Delta in Nigeria is subject to anthropogenic influences, impacting the quality of its water bodies, including the Sombrero River. This study aims to investigate the concentrations of metals and metalloids in Gobius niger from the Sombrero River, as these contaminants can pose risks to human health through seafood consumption. Specifically, zinc (Zn), iron (Fe), copper (Cu), lead (Pb), arsenic (As), and cadmium (Cd) were analyzed using atomic absorption spectroscopy (AAS).

Materials and Methods

Samples were collected from three different stations along the Sombrero River. The concentrations of Zn, Fe, Cu, Pb, As, and Cd were determined using AAS. Hazard Quotients (HQ), Chronic Daily Intake (CDI), Hazard Index (HI), and Individual Lifetime Cancer Risk (ILCR) values were calculated to assess the potential health risks associated with consuming fish contaminated with these metals and metalloids.

Results

Station 1 had the highest Zn concentration, followed by Fe, Cu, Pb, Cd, and As, with Zn reaching 104.8 ± 1.37 mg kg⁻¹. Station 2 exhibited a similar trend, while Station 3 had Zn as the predominant metal and metalloid. Notably, Pb, As, and Cd levels were consistently low at all stations. While Pb was within permissible limits set by FAO/WHO for contaminants in the fish samples, Zn exceeded regulatory guidelines, suggesting a potential source of contamination. Hazard Quotients (HQ) highlighted a significant risk associated with zinc, especially for children. Chronic Daily Intake values showed metals in fish consumed by adults and children were generally within safe limits, except for Zn, which exceeded Maximum Tolerable Daily Intake (MTDI). Hazard Index values pointed to a substantial long-term health risk, particularly for children due to high zinc levels. However, Individual Lifetime Cancer Risk (ILCR) values were generally below 1, indicating relatively low cancer risks from G. niger consumption for both age groups.

Conclusion

This study emphasizes the need for monitoring and managing metals and metalloid pollution in the Niger Delta region to ensure safe seafood consumption and community well-being. While certain metals pose minimal health risks, it highlights the necessity of specific interventions to reduce excessive zinc exposure and safeguard long-term health in the region.