Mean Concentrations Of Manganese Research Articles

Evaluation of the heavy metal levels from selected food cultivars, from coal mining communities of Enugu State, Nigeria

Food cultivars from Akwuke, Ngwo and Udi were analyzed for their heavy metal content using the atomic absorption spectrometry (AAS). The mean concentrations of Manganese in leafy vegetable ranges from 1170±6.20µg/g and in chromium from 110±0.0 µg/g, in lead from 320±210, in cadmium from 30±10 µg/g and nickel from 10±0 µg/g all in Akwuke. The transfer factors results for the three communities shows that the pumpkin leafy have the highest transfer factor for manganese, 2.6 in Akwukeand chromium yam 2.465 in Udi, while Nickel has the least transfer factor in all the food cultivars in the three communities with 0 result. This study has revealed high concentration of manganese, lead, chromium cadmium and nickel in food cultivars in the three studied area Akwuke, Ngwo and Udi, all in Enugu State. Though the concentrations of these heavy metals were not high in any of the soil samples, but high concentration of these heavy metals, compared to WHO/FAO in food cultivars were observed, especially in Udi and Ngwo community. Keywords: Heavy metal, levels, food cultivars, Enugu State and Nigeria

Revealing the evolution mechanism from spot segregation to banded defect above the austenitization temperature

Spot segregation and banded defect are unsolved technical problems of high-quality steel. In this paper, spot segregation of different sizes and irregular morphology were found in equiaxed crystal zones of slab. The characteristics of speckle type and porosity type spot segregation were compared, where the segregation degree of large-size spot segregation was worse. After heat treatment and hot rolling processes, the concentration changes of carbon, manganese, and iron were obtained by EPMA and SEM-EDS. The results showed that the carbon distribution became more even but the change in manganese concentration was not obvious, and the maximum concentration of carbon was almost unchanged, which indicated that severe segregation cannot be alleviated by the existing processes. Circular and irregular atoms were found in the banded defect. These atoms cooperate with thermodynamic coupling caused by hot rolling and contribute to the composition homogenization and void healing of the banded defect. In addition, the connection between holding time and diffusion efficiency was studied by simulating the uphill diffusion process of carbon and manganese at a holding temperature of 1250 °C. When the diameter of the spot segregation was less than 3000 μm, the carbon could uniformly diffuse before 12,000 s, and then if the spot segregation was kept warm for 36,000 s, the mean concentration of manganese was still less than 1.0 wt%, which is too high to be considered homogenized. Finally, an evolution model was established to explain the formation process and evolution mechanism from spot segregation to band defect.

Evaluation of iron and manganese removal effectiveness by treatment plant modules based on water pollution index; a comprehensive approach.

Groundwater is a viable alternative when access to surface water resources is limited. Iron and manganese are known ions in soil and naturally in groundwater sources. However, human activities also are responsible. To identifying the best module for removing manganese and iron in the water treatment plant (WTP) of Mazandaran, 516 samples were taken from raw and treated water. The concentration of manganese, iron, was measured by atomic absorption spectrophotometry, and turbidity was used with the nephelometry method. The water pollution index (WPI) was applied for categorizing the status of pollution in treated water. The effect of seasonal temperature and backwashing (At flow rates of 3.5, 9.2, and 15.3m h-1) on the sand filter efficiency was also investigated. The highest concentrations of manganese, iron, and turbidity in raw water were 0.744, 6.70mg L-1, and 41.8 NTU, and in treated water were 0.67, 1.09mg L-1, and 5.58 NTU, respectively. The mean concentration of manganese and iron in raw and treated water were 0.24 ± 0.1, 0.93 ± 0.91, 0.105 ± 0.06 and 0.18 ± 0.14mg L-1 respectively. The WPI statuses in drinking water were excellent for manganese and iron in 95.74 and 53.88 % of the samples and very poor in 1.16 and 12.01 % of the samples, respectively, and its classification for drinking water for manganese and iron was excellent ˃ good ˃ extremely polluted ˃ polluted and the concentration of iron was more than manganese in treated water. The study of temperature's effect on sand filters showed that the removal efficiency in warm seasons was higher than in cold seasons. Also, the turbulence in the backwash with the 9.2m h- 1 rates, is lesser than other speeds, and in this flow, after 270s, the turbidity decreases to less than 10 NTU. Spearman correlation comparison showed that the parameters amounts after filtration decreased significantly (p ≤ 0.0001) in comparison to raw water. The results showed that module #1 that used open-aeration and chlorine as oxidations, was most effective in removing iron and manganese. In the end, the WTP couldn't diminish the parameters completely and need subsidiary units.

Analysis of Manganese Bioaccumulated in Mediterranean Blue Mussel (Mytilus galloprovincialis) from the Bay of Mali Ston (Adriatic Sea, Croatia) during Diarrhetic Shellfish Poisoning Toxicity

Diarrhetic Shellfish Poisoning (DSP) toxicity was revealed in the Mediterranean blue mussel (Mytilus galloprovincialis) from the Bay of Mali Ston, in the south part of the Eastern Adriatic Sea, through the Croatian National Monitoring Programme in the period from January until June of 2011. A survey of DSP toxicity within the frame of regular controls carried out through the mouse bioassay (MBA, at the time the official method for DSP toxins) demonstrated that in some incidents, positive MBA, which manifested by the atypical symptomatology of the animals, dominated. Additional studies were done to explain the atypical results of the conducted biological tests at the time. In the current study, the bioaccumulated manganese concentration in the soft tissues of mussels was measured to investigate its influence on the MBA results. In both DSP negative and DSP positive samples, which were prepared for the analysis according to the modified US EPA 3052 method, the concentration of the bioaccumulated manganese was performed on the atomic absorption spectrometer using flame atomic absorption spectroscopy technique. The analysis revealed higher concentration of manganese in 87% of DSP positive samples and the expressed per wet weight ranged from 0.15 to 5.38 mg kg−1. The mean concentration of manganese for all DSP positive samples was 1.78 mg kg−1, while for DSP negative samples, it was 48% lower (0.93 mg kg−1). The highest concentration of manganese in DSP positive samples was measured in February 2011. Since the low concentrations of lipophilic biotoxins gymnodimines (GYMs) and spirolides (SPXs) were also detected in the analysed DSP positive samples in the parallel studies, the results obtained in this study suggest future investigations of the connection between the concentration of manganese and lipophilic biotoxins.

Impact of delivery mode on the levels of essential trace elements in breast milk

Aim: This study investigated whether the parturition mode (vaginal or cesarean [C-] section) affects breast milk concentrations of four essential trace elements (iron, copper, zinc, and manganese).Methods: Women giving birth at seven hospitals in seven different regions of China were enrolled in the study. Each participant provided breast milk, collected on postpartum day 3–5, for determination of iron, copper, zinc, and manganese concentrations. Breast milk concentrations of the subject trace elements were compared between women giving birth vaginally or via C-section.Results: Of the 1243 women enrolled in the study, 617 (49.6%) gave birth via the vaginal route and 626 (50.4%) delivered via C-section. The mean milk concentrations of iron, copper, zinc, and manganese in the milk of women delivering via the vaginal route were higher than those in the milk of women delivering via C-section; only the copper concentration differences were statistically significant, after adjusting for confounding factors (p = .023).Conclusion: Delivery mode impacts breast milk concentrations of essential trace elements, with vaginal delivery being associated with higher essential trace element concentrations than C-sections.

Statistical analysis of shallow well characteristics as indicators of water quality in parts of Ibadan City, Nigeria

The inability of private well-owners to conduct well-water tests is a major obstacle to addressing contamination of water for human consumption in Ibadan city. Shallow well characteristics and their water quality were assessed with the aim of identifying observable characteristics that serve as markers of well water status. Field observation and interviews were employed to assess the features of 100 shallow wells. In addition, physicochemical and bacteriological parameters of water samples from selected wells were analysed. Out of 100 wells, the aggregate score of 60% ranged from high to medium risk. The mean concentrations of manganese, iron, total dissolved solids, pH and bacterial population were outside the WHO permissible limit in more than 50% of the sampled wells. Wells with poor locational characteristics had high turbidity and bacterial population (P < 0.05). A regression model showed that improved structural and maintenance scores of wells will reduce bacterial load in the well water; hence their scores can indicate water quality status.

A Comparative Study on the Impact of Avu and Ihie Dumpsites on Soil Quality in Southeastern Nigeria

The effects of leachate from unlined open waste dumps on the soil and aquifer system in Avu and Ihie area of Southeastern Nigeria was investigated in this study. The soil pH in both dumpsites is very low and it is a reflection of the microbial action in the process of decomposition of waste materials as well as the acid-rain formation via gas flaring. It was established that the mean concentrations of manganese, lead, iron and bacteria count were higher in Avu dumpsite soil while the other parameters are higher at Ihie dumpsite soil. The concentrations of all the parameters analyzed were below the crustal abundance of the respective elements except cadmium. The high concentration of cadmium can be attributed to the decay of abandoned electric batteries and other electrical parts. The soil samples collected far away from the dumpsites have lower concentrations compared to the samples collected in the vicinity of the dumpsites suggesting a possible soil contamination via leachate from the nearby dumpsites. The graphs of sieve and correlation analyses from the dumpsites were very similar and this implies similarity in wastes materials and geohistory. Construction of future dumpsites in the area should follow the prescribed design of a modern sanitary landfill system that quarantee protection to the soil and aquifer materials.

Serum Concentrations of Iron, Copper, Zinc, Manganese and Cobalt in Anoestrus Cattle and Buffaloes under Farm Condition

The present study was planned to determine serum micro-mineral status (iron, copper, zinc, manganese, cobalt) in 50 anoestrus Murrah buffalo, Sahiwal and Crossbred cows and heifers. Serum micro-mineral contents were determined by atomic absorption spectrophotometer. Mean serum concentrations of iron, copper, zinc, manganese and cobalt taken from 14 Murrah buffalo cows and heifers were 2.82 ± 0.65, 0.48 ± 0.20, 2.65 ± 1.46, 0.24 ± 0.06 and 0.49 ± 0.24ppm, respectively. These mean values were 2.47 ± 1.35, 0.52 ± 0.16, 3.69 ± 2.57, 0.18 ± 0.09 and 0.56 ± 0.22ppm, respectively in 20 Sahiwal cow and heifers, while, 3.16 ± 1.05, 0.45 ± 0.13, 2.76 ± 1.51, 0.21 ± 0.07 and 0.51 ± 0.22ppm, respectively in 16 crossbred cow and heifers. Compared with normal range of these trace elements in healthy animals the level of copper was on a border way to show the signs of clinical deficiency symptoms, while the levels of other elements was in quite safe range to encounter any problem. It was concluded that deficiency of copper, could be responsible for anoestrus condition in these animals. Thus, to overcome the deficiency, strategic dietary supplementation of copper with better bioavailability could be a suitable approach.

Embryo Abortion in Relation to Fruit Size, Quality, and Concentrations of Nutrients in Skin and Pulp of Mango

ABSTRACT To investigate the effects of embryo abortion on fruit size and weight, stone weight, and fruit quality, including total soluble solids (TSS), acidity, TSS/acid ratio, sugars, and concentrations of macro and micronutrients in skin and pulp, nubbins (seedless fruit) and seeded fruit of mango (Mangifera indica L.) cultivars ‘Glenn,’ ‘Irwin,’ ‘Haden,’ ‘Kent,’ and ‘Kensington Pride’ were compared at the ripe stage. Nubbins had significantly smaller fruit size and lower fruit weight than in seeded fruit in all the cultivars. Mean stone weight was also significantly lower in nubbins (9.04 g) than in seeded fruit (30.27 g) and the trend was similar in all the cultivars. Percent dry pulp weight was significantly higher in nubbins than in seeded fruit in all five cultivars. Nubbins exhibited significantly lower acidity and higher TSS and TSS/acid ratio than did seeded fruit in all of the cultivars. The concentrations of nitrogen (N), potassium (K), magnesium (Mg), iron (Fe), and copper (Cu) in the skin and N, phosphorus (P), K, calcium (Ca), Mg, sulfur (S), Fe, zinc (Zn), and Cu in the pulp of nubbins did not differ significantly from those in the skin and pulp of seeded fruit in all of the cultivars. However, mean concentrations of P, Ca, and S were significantly higher in the skin of nubbins than in the skin of seeded fruit. Mean concentrations of manganese (Mn) and boron (B) in both skin and pulp of nubbins were significantly higher than in the skin and pulp of seeded fruit. The experimental results suggest that embryo abortion at early stages of fruit development, although it reduces fruit size and weight, does not affect the concentrations of these elements in the pulp and skin of mature fruit. In conclusion, embryo abortion in mango fruit substantially reduced fruit size, weight, and stone weight and improved TSS, TSS/acid ratio, total sugars, and non-reducing sugars compared with seeded fruit in all the cultivars and led to minor changes in the concentrations of most of macro and micronutrients in skin and pulp of the fruit.

Neutron activation analysis of trace elements in skin. II. Manganese in normal skin.

SUMMARY.— Manganese levels in normal epidermis and dermis from 34 cadavers were estimated by neutron activation analysis. The mean concentration of manganese in the epidermis was 4 times higher than that in the dermis. An important biological role of manganese in skin is suggested by the remarkably narrow range of concentration of that trace metal in the analysed samples.

Neutron Activation Analysis: The Determination of Manganese

Criteria pertaining to biochemical applications of neutron activation analysis were formulated and dealt with experimentally. An ultramicromethod was described which permits the determination of the essential microconstituent, manganese, in biological samples, including small pools with low concentrations. Samples containing, on the average, 0.261 m mu g of manganese were analyzed with a variance of plus or minus 3.4%. The mean concentration of manganese in human plasma was 2.69 mu g per liter. The plasma concentration remained constant in the rabbit after injections of manganous sulfate whereas that of whole blood increased. Manganese concentrations were determined in some tissues and in some reagents. (auth)