Browsing by Author "Tebandeke, Emmanuel"

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    Organochlorine pesticide residues in Uganda’s honey as a bioindicator of environmental contamination and reproductive health implications to consumers
    (Ecotoxicology and Environmental Safety, 2021) Mukiibi, Stuart Ben; Nyanzi, Steven Allan; Kwetegyeka, Justus; Olisah, Chijioke; Matthew Taiwo, Adewale; Mubiru, Edward; Tebandeke, Emmanuel; Matovu, Henry; Odongo, Silver
    Honey has multifaceted nutritional and medicinal values; however, its quality is hinged on the floral origin of the nectar. Taking advantage of the large areas that they cover; honeybees are often used as bioindicators of environmental contamination. The focus of the present paper was to examine the quality of honey from within the vicinity of an abandoned pesticide store in Masindi District in western Uganda. Surficial soils (< 20 cm depths) and honey samples were collected from within the vicinity of the abandoned pesticide store and analysed for organochlorine pesticide (OCP) residues using gas chromatograph coupled to an electron capture detector (GCECD). The mean level of ΣDDTs in all the soil samples was 503.6 μg/kg dry weight (d.w). ΣDDTs contributed 92.2% to the ΣOCPs contamination loads in the soil samples, and others (lindane, aldrin, dieldrin, and endosulfans) contributed only 7.8%. Ratio (p, p′-DDE + p, p′ -DDD)/p, p′ -DDT of 1.54 suggested historical DDT input in the area. In all the honey samples, the mean level of ΣDDTs was 20.9 μg/kg. ΣDDTs contributed 43.3% to ΣOCPs contamination loads in the honey samples, followed by lindane (29.8%), endosulfans (23.6%) and dieldrin (3.2%), with corresponding mean levels of 14.4, 11.4 and 1.55 μg/kg, respectively. Reproductive risk assessment was done based on the hazard quotient (HQ) and hazard index (HI) procedure. In our study, the calculated HIs for adults (102.38), and children (90.33) suggested high potential health risks to the honey consumers. Lindane, endosulfan and p, p′ -DDD detected in the honey samples at levels exceeding the acute reference dose (ARfD) are known risk factors for spontaneous abortion, reduced implantation, menstrual cycle shortening, impaired semen quality, and prostate cancer in exposed individuals and experimental animal models.
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    Spectrophotometric Determination of Low Levels of the Orthophosphate Anion as Molybdenum Blue using Sodium Thiosulphate Reducing agent
    (Oriental Journal of Chemistry, 2020) Nalumansi, Irene; Birungi, Grace; Moodley, Brenda; Tebandeke, Emmanuel
    A simple spectrophotometric method for the determination of low levels of the orthophosphate (PO4 3-) in environmental water systems is reported. The method is based the formation of the phosphomolybdate from the condensation of molybdate and orthophosphate in aqueous acid medium followed by reduction with sodium thiosulphate to form phosphomolybdenum blue. The system obeys Beer’s law at 880 nm (λmax) in the 0.005–0.06 mg P mL-1 phosphate concentration range. Molar absorptivity, Sandell’s sensitivity and correlation coefficient values for the determination were 57526 L mol-1 cm-1, 0.2835 μg cm-2 and 0.9948 respectively. The limit of detection was 2.213 x 10-3 mg P mL-1. The results of PO4 3- determination in water samples obtained using the spectrophotometric method developed in this study, compare favourably with those generated using the Murphy and Riley method which is commonly used for this analysis. Therefore, the study ably demonstrates the suitability of the present spectrophotometric method for analysis of the orthophosphate in environmental water samples.