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Water is an essential component of all living things on earth and the contamination of water by heavy metals can cause detrimental health effects. This study aimed to determine the health risk posed by trace elements (Fe, Zn, Cu, Mn, Ni, Cr, Cd, Co, Pb, and As) present in the drinking water supplies of Gullele and Akaki-Kality Sub-Cities, upstream and downstream parts of Addis Ababa, respectively. The concentrations of the potentially toxic trace elements in the water samples were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). The highest concentration of the heavy metals was observed for Iron. Cadmium and cobalt were not detected in any of the tap water samples. Samples from Gullele contained higher levels of Fe and Mn, 220.3 ± 0.17 and 19.78 ± 0.08 μg/L, respectively compared to Akaki-Kality, 38.87 ± 0.14 and 2.08 ± 0.01 μg/L, respectively. Conversely, tap water from Akaki-Kality contained significantly higher levels of As than that from Gullele. Additionally, Cr and Ni were detected only in samples from Akaki-Kality, which might be due to the various industries in the area. The highest incremental lifetime cancer risk was found for arsenic, with values for children and adults in Akaki-Kality 2.50 × 10 −4 and 4.50 × 10 −4 , respectively. Likewise, in Gullele Sub-City, it was 5.00 × 10 −5 and 1.00 × 10 −4 for adults and children, respectively. The results indicate that carcinogenic risk occurrence is probable from As in both studied areas.

BACKGROUND This study was aimed at the development of objective analytical method capable of verifying the production region of the coffee beans. One hundred samples of green coffee (Coffea arabica L.) beans from the major producing regions, comprising various sub‐regional types, were studied for variations in their fatty acid compositions by using gas chromatography coupled with mass spectrometry. Principal component analysis (PCA) was used to visualize data trends. Linear discriminant analysis (LDA) was used to construct classification models. RESULTS Twenty‐one different fatty acids were detected in all of the samples. The total fatty acid content varied from 83 to 204 g kg−1 across the regions. Oleic, linoleic, palmitic, stearic and arachidic acids were identified as the most discriminating compounds among the production regions. The recognition and prediction abilities of the LDA model for classification at regional level were 95% and 92%, respectively, and 92% and 85%, respectively, at sub‐regional level. CONCLUSION Fatty acids contain adequate information for use as descriptors of the cultivation region of coffee beans. Chemometric methods based on fatty acid composition can be used to detect fraudulently labeled coffees, with regard to the production region. These can benefit the coffee production market by providing consumers with products of the expected quality. © 2019 Society of Chemical Industry

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BackgroundCannabis sativa L. is one of the illicit drug bearing plants. Cannabis products are the most widely trafficked drugs worldwide. The highest levels of cannabis production in the world take place in the African continent. A small volume of cannabis is produced in rural areas of Ethiopia, of which a small portion is exported to neighboring countries and the majority is consumed at home. The literature survey revealed that there is no report on the metal contents in cannabis cultivated in Ethiopia. The main objective of this study is to determine the level of selected metals in leaves of Cannabis sativa L. cultivated in Ethiopia.MethodsCannabis sativa L. samples were collected from Metema (Amhara Region), Mekelle (Tigray Region), Sheshemene (Oromia Region) and Butajira (South Nations Nationality and Peoples (SNNP) Region) of Ethiopia. After proper sample pretreatment, the volumes of reagents used, digestion temperature and digestion time were optimized and using the optimized conditions the levels of metals were determined by flame atomic absorption spectrometry.ResultsThe accuracy of the optimized procedure was evaluated by analyzing the digest of the spiked samples with standard solution and the percentage recoveries varied from 88 to 103%. The levels of metals determined (µg/g dry weight) were in the ranges Ca (657–1,511), Zn (321–380), Ni (124–172), Cu (122–176), Cd (3–10), Pb (8–10), and Cr (4–8). Zn was with the highest concentration among trace metals.ConclusionA statistical analysis of variance (ANOVA) at 95% confidence level indicated that there is a significant difference in the levels of all the metals between the four sample means except Pb. The results indicate that the content of Pb and Cd exceeds the permissible amount for medicinal plants which form the raw materials for the finished products set by World Health Organization (WHO).

This study aimed to investigate the antioxidant activity and polyphenolic content of a wild vegetable, Urtica simensi, grown in Ethiopia. Total phenolics, tannin and flavonoid content of leaves extract were determined by the Folin Ciocalteu, Folin Ciocalteu/protein precipitation and aluminum chloride methods, respectively. The antioxidant activity was tested by the DPPH (1,1-diphenyl-2picrylhydrazyl) free radical scavenging method. Results of the determination revealed that total phenols ranged from 15.75 to 22.67 mg gallic acid equivalent/g of dried leaves. Total tannin content ranged between 0.496 to 1.54 mg gallic acid equivalent/g of dried leaves. Similarly, total flavonoids concentration as catechin equivalent varied between 6.89 to 9.03 mg catechin equivalent/g of dried leaves. Leaves of U. simensis were found to have a substantial antioxidant activity ranging between 2.28-2.42 mg ascorbic acid equivalent/g of dried leaves. This study reveals that U. simensis leaves accumulated a substantial amount of polyphenols, particularly flavonoids, and pose a substantial antioxidant activity.

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