Browsing by Author "Othman, Othman Chande"
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Item LEVELS OF HEAVY METALS IN DEPOSITED DUST AND SOIL FROM SELECTED PRIMARY SCHOOLS IN DAR ES SALAAM(Tanzania Journal of Science, 2018) Philip, Joseph Yoeza Naimani; Mkenga, Eliamini Ismail; Othman, Othman ChandeThe objective of this study was to examine the levels of heavy metals, lead, manganese, nickel, copper, chromium and cadmium in standard one and kindergarten classroom dusts and playing ground soils from selected primary schools along Morogoro road highway (Kimara, Mbezi, Kibamba and Kiluvya primary schools) and away from Morogoro road highway (Makabe, Msumi and Mbopo primary schools) as well as in the Dar es Salaam city center (Uhuru, Mzimuni, Dr. Omari Ali Juma, Manzese and Ubungo National House primary schools), Tanzania. The samples were acid digested and the supernatant analyzed using inductively coupled plasma optical emission spectrometer (ICP-OES). The mean concentrations (mg/kg) range of heavy metals in kindergarten and standard one classroom dust samples were bdl – 3.2 ± 0.2 (Cd), 14.7 ± 0.5 – 30.1 ± 2.2 (Cr), 6701 ± 1201– 277775 ± 32632 (Mn), 5.18 ± 0.59 – 122 ± 145 (Cu), 6.95 ± 1.57 – 30.3 ± 31.1 (Ni) and 17.67 ± 3.56 – 104.9 ± 94.7 (Pb). Similarly, the mean concentrations (mg/kg) range of heavy metals in kindergarten and standard one playing ground soil samples were bdl – 1.86 ± 0.06 (Cd), 5.8 ± 0.8 – 105 ± 124 (Cr), 7176 ± 226 – 191779 ± 82776 (Mn), 1.64 ± 0.01 – 11.51 ± 6.5 (Cu), 1.11 ± 0.2 – 37.5 ± 45.9 (Ni) and 8.9 ± 2.4 – 34.04 ± 1.9 (Pb). The present results, which indicate significantly high levels of heavy metals in school classroom dusts and playing ground soils, signify an important advancement towards shedding light on the alarming threat to school children’s health since classrooms and playing grounds are their immediate environments where they spend significant amount of their early life time.Item LEVELS OF HEAVY METALS IN SELECTED FACIAL COSMETICS MARKETED IN DAR ES SALAAM, TANZANIA(Tanzania Journal of Science, 2018) Philip, Joseph Yoeza Naimani; John, Silvia; Othman, Othman ChandeThe aim of this study was to determine the levels of heavy metals: lead, cadmium, copper, zinc, arsenic and mercury in facial cosmetics (lipstick, lip glossy, facial powder, foundation, eyeliner, eye shadow and mascara) which were purchased randomly in Dar es Salaam, Tanzania. The levels of lead, cadmium, copper and zinc were determined using Atomic Absorption Spectrometry (AAS). The levels of arsenic were determined using Hydride Generation Atomic Absorption Spectrometry (HGAAS), and levels of mercury were determined using Cold Vapour Atomic Absorption Spectrometry. Prior to determination of the concentration of heavy metals, the samples were acid digested. The average order of concentration of heavy metals in the sample was found to be zinc > lead > cadmium > copper >arsenic > mercury (foundation), zinc > cadmium > lead > arsenic > copper > mercury (powder), copper > lead > cadmium > zinc > arsenic > mercury > (eye shadows), zinc > copper > lead > cadmium > mercury > arsenic (eyeliners), zinc > cadmium > mercury > copper > lead >arsenic (mascaras), zinc > lead > cadmium > arsenic > copper > mercury (lipsticks), lead > cadmium > zinc > copper >arsenic > mercury (lip glossy). The observed higher percentage concentrations of heavy metals beyond limits of Canadian standards for cosmetics were as follows: lead 62.79%, cadmium 16.28%, arsenic 34.88% and mercury 6.98%.