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Open Access January 02, 2025

Ambient Air Quality and Human Health Risk Assessment of Heavy Metals in a Potentially Toxic Silver-Polluted Environment

Abstract Silver nanoparticles (Ag+NPs) contamination in the environment is a serious concern. This study investigated selected heavy metal (Ag+, Cd2+, Cr2+ and Pb2+) concentrations at different sampling points to assess the risk to human health (infants, children, and adults). To do this, an enclosed area (laboratory) of 12.6 m X 8.5 m (107.1 [...] Read more.
Silver nanoparticles (Ag+NPs) contamination in the environment is a serious concern. This study investigated selected heavy metal (Ag+, Cd2+, Cr2+ and Pb2+) concentrations at different sampling points to assess the risk to human health (infants, children, and adults). To do this, an enclosed area (laboratory) of 12.6 m X 8.5 m (107.1 m2) was clearly marked at different coded distances of S1, S2, S3, and S4 representing 2, 4, 6, and 8 m, while unpolluted atmosphere at 50 m away without Ag+NPs served as the control (S5). The silver fireworks were allowed to burn for an approximate 00h03m30s at each sampling points using a high-volume air sampler mounted at the Environmental Engineering Departmental Laboratory, Rivers State University, with windows and doors closed to simulate indoor conditions. Samples were digested using a mixture of analytical-grade nitric acid, analytical-grade hydrochloric acid and analyzed to evaluate the levels of heavy metals by atomic absorption spectrophotometry. The Ag+ result at S1 shows 30,000 µg/cm3, S2 was 29,000 µg/cm3, while S3 was 28000 µg/cm3 and then S4 was 13,000 µg/cm3. These results exceeded the permissible values of the United States National Ambient Air Concentration for rural, urban and industrial areas (0.0005, 0.004 and 0.6 µg/cm3, respectively). The result for the control (S5) (0.037 µg/cm3) was within the maximum allowable value. Results from other heavy metals such as Cd were 1000, 743, 401, 153, 0.001 µg/cm3, Cr was 5000, 4000, 3729, 2960, 0.002 µg/cm3, Pb was 0.048, 0.041, 0.035, 0.034 and 0.01, µg/cm3, respectively. However, higher values of Ag+, Cd, and Cr indicated a higher propensity for the metals to be toxic (bioavailable). In addition, the assessment of the potential health risk posed by these metals proved contaminated and harmful. Visitors recorded high values in exposure concentration (EC) and low values in average daily dose (ADD).
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Open Access November 05, 2024

Effect of Different Processing Methods on Total Phenolic and Total Flavonoid Content of Selected Indigenous Vegetables

Abstract Foods rich in phytochemicals are well recognized for their role in the prevention of chronic disease development, in addition to fulfilling the nutrient requirements. However, different processing methods employed during preparation may affect their levels and functionality as they are sensitive to different processing parameters such as temperature and light. This study aimed to evaluate the effects of three common processing methods; boiling, fermentation, and drying (sun and solar drying, with and without blanching), on total phenolic content and total flavonoid content in cassava (Manhot esculenta Crantz), black jack (Bidens pilosa) and bitter lettuce leaves (Launaea cornuta [...] Read more.
Foods rich in phytochemicals are well recognized for their role in the prevention of chronic disease development, in addition to fulfilling the nutrient requirements. However, different processing methods employed during preparation may affect their levels and functionality as they are sensitive to different processing parameters such as temperature and light. This study aimed to evaluate the effects of three common processing methods; boiling, fermentation, and drying (sun and solar drying, with and without blanching), on total phenolic content and total flavonoid content in cassava (Manhot esculenta Crantz), black jack (Bidens pilosa) and bitter lettuce leaves (Launaea cornuta) grown in Mkuranga District in the Eastern part of Tanzania. Total phenolic content and total flavonoid content were analyzed by using the spectrophotometric method with the use of Folin-Ciocalteu and Aluminum Chloride reagents, respectively. Total phenolic content ranged from 0.9±0.14 to 85.7 ± 0.56 mg Gallic Acid Equivalent (GAE)/100g and flavonoids ranged from 0.03±0.00 to 3.9±0.03 mg/100g across the treatments. Both parameters were adversely affected by fermentation and boiling, while solar and sun drying only reduced the flavonoid content. Results showed that direct solar and sun drying appear to be effective processing methods, for the retention and maintenance of total phenolic content in all samples while, none proved to be effective for flavonoid content.
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Open Access October 19, 2024

The Impact of Extracurricular Activities on Learner's Achievement in EFL: A Study at Daffodil International University

Abstract Extracurricular activities and academic performance are connected in every aspect of the education system. Daffodil International University is one of the top universities in Bangladesh that focuses on student improvement through extracurricular activities. Extracurricular activities help students improve skills like leadership, teamwork, and analytical abilities. Do extracurricular activities [...] Read more.
Extracurricular activities and academic performance are connected in every aspect of the education system. Daffodil International University is one of the top universities in Bangladesh that focuses on student improvement through extracurricular activities. Extracurricular activities help students improve skills like leadership, teamwork, and analytical abilities. Do extracurricular activities help English as a Foreign Language (EFL) students improve their academic performance? This evaluation aims to find out this question among Daffodil International University students. The study focused on both qualitative and quantitative data. Therefore, the data analysis followed a mixed method. The quantitative data focused on the students' participation in extracurricular activities. Respectively, the comparison between their participation and EFL course improvement. On the other hand, the qualitative data focused on the interviewee's experience. However, it's been proven that though extracurricular activities help students improve their other soft skills, they actually don't have as much impact on improving their EFL course curriculum performance.
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Open Access March 05, 2024

Phenolic compounds and antioxidant properties of roasted maize-peanut product (Zowey) and its potential to alleviate oxidative stress

Abstract Background: The study of phenolic compounds and their potential to contribute to health is a major interest in research. This work was to determine phenolic compound contents as well as antioxidant properties of roasted maize-peanut snack product with and without spices. Methods: HPLC was used to determine the phenolic composition of the maize flours, peanut flour and their composite [...] Read more.
Background: The study of phenolic compounds and their potential to contribute to health is a major interest in research. This work was to determine phenolic compound contents as well as antioxidant properties of roasted maize-peanut snack product with and without spices. Methods: HPLC was used to determine the phenolic composition of the maize flours, peanut flour and their composite snacks with and without spices. Total phenolic content (TPC), total flavonoid content (TFC), tannin content (TC) and radical scavenging activity (measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis (3- ethylbenzothiazoline-6-sulphonicacid) (ABTS) and hydrogen peroxide radical scavenging assays was also used. Results: TPC of the extract of roasted maize flour, roasted peanut flour and composite roasted maize-peanut flour ranged from 48.93 to 178.31 mg GAE/100 g, while the TFC was 3.18–25.94 mg CE/100 g and TC (0.22 – 0.73 mg CE/g). The dominant phenolic acid was protocatechuic acid ranged from 13.73 to 1643.54 µg/g. Among the flavonoids, quercetin and catechin were dominant. The extracts of the free soluble fraction exhibited 23.88 – 81.52 %, 49.59 – 85.17 % and 0.58 -5.13 µmol AAE/g of DPPH, hydrogen peroxide and ABTS radical scavenging abilities respectively. Conclusion: Maize–peanut product showed potential ability in contributing to alleviating radical induced oxidative stress.
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