https://ir.unisa.ac.za/handle/10500/2908 2026-05-05T17:20:20Z 2026-05-05T17:20:20Z Zuma, Vincent Thulani https://ir.unisa.ac.za/handle/10500/32317 2026-03-20T11:26:51Z 2025-11-01T00:00:00Z

Selected soil trace metals in KZN, Cedara : their concentration, adsorption, extraction methods and threats to food security Zuma, Vincent Thulani This study investigated the concentrations of cadmium (Cd), copper (Cu), chromium (Cr), cobalt (Co), zinc (Zn), manganese (Mn), nickel (Ni) and lead (Pb) in soils from Cedara Research Farm in KwaZulu-Natal, South Africa. Soil samples were collected using a beta soil auger from areas representing different land uses and analysed for total and bioavailable metal concentrations. Total metals were determined through complete acid digestion, while bioavailable fractions were assessed using the Ambic-2 extraction method. Metal concentrations were quantified using inductively coupled plasma–atomic emission spectroscopy (ICP-AES) and atomic absorption spectroscopy (AAS). The mean concentrations of metals followed the order Mn > Pb > Zn > Cr > Ni > Cu > Co > Cd, with values of 245.57, 206.94, 127.19, 98.76, 23.80, 21.83, 2.16 and 0.97 mg·kg−1, respectively. The concentrations of Cr, Cu, Pb and Zn exceeded the allowed limits for agricultural soils, while Co was undetectable at all sites. Cadmium was detected in only three fields and Ni remained within acceptable limits across all sites. Manganese levels were consistently higher than those at the control site. The pollution indices (Igeo, EF and CF) indicated significant contamination by Cu, Zn and Mn, particularly in non-agricultural fields. However, the cropping areas exhibited comparatively lower concentrations, suggesting the mobilisation and partial removal of metals through agricultural activity. Comparison with background values from the 1970s confirmed ongoing soil contamination. Between the two extraction methods tested, Ambic-2 extracted higher and more consistent metal concentrations than ammonium-EDTA. Elevated levels of heavy metals in these agricultural soils pose potential risks to food safety and human health. Routine monitoring and inclusion of heavy metal analyses in standard soil fertility assessments are recommended to improve soil management and mitigate heavy metal pollution.

2025-11-01T00:00:00Z Sadiki, Ntsieni Eric https://ir.unisa.ac.za/handle/10500/32181 2026-02-26T12:24:40Z 2025-08-01T00:00:00Z

Assessing the environmental impacts and occupational risk of solid waste reclamation by waste pickers in Goudkoppies landfill site, Soweto township, South Africa Sadiki, Ntsieni Eric The reclamation of recyclables in landfill sites has both negative and positive impacts, as these recyclables are recognised as valuable resources that support the livelihoods of underprivileged communities. However, waste pickers are exposed to different occupational health risks, harmful contaminants, and social problems. The aim of this study was to assess the environmental impact and occupational risks of solid waste reclamation by the waste pickers in Goudkoppies Landfill Site in Soweto, which has approximately 2 000 waste pickers. The study employed a convergent mixed-methods approach, purposively selecting 17 interview participants and randomly sampling 152 questionnaires administered to waste pickers, landfill officials, and buyback centre owners or managers. Data were also collected through site observations. Qualitative data were manually and inductively explored whilst the quantitative data were analysed using the Statistical Package for the Social Sciences version 2.9 (SPSS). The results showed that waste picking contributed positively by recovering recyclable materials, supporting the sustainable cleaning of the physical environment, and prolonging the landfill’s lifespan. However, the reclamation at the landfill site had negative environmental impacts, including littering, fire hazards and unsafe picking practices. The waste pickers were also exposed to dangerous occupational risks such as offensive odour, noise pollution, respiratory diseases, glass cuts and food poisoning. These conditions made the landfill site an unconducive working environment and posed serious threats to the health and lives of the reclaimers.; U vusuludzwa ha zwithu zwine zwa nga shumiswa hafhu fhethu hune ha laṱiwa hone mathukhwi zwi na masiandoitwa mavhi na avhuḓi, sa izwi zwithu izwi zwine zwa nga shumiswa hafhu zwi tshi dzhielwa nṱha sa zwishumiswa zwa ndeme zwine zwa tikedza matshilo a zwitshavha zwi si na zwishumiswa. Naho zwo ralo, vhathu vha kuvhanganyaho mathukhwi vha ṱangana na khombo dzo fhambanaho dza mutakalo musi vha tshi kho kuvhanganya mathukhwi, zwithu zwi tshikafhadzaho zwi re khombo, na thaidzo dza matshilisano. Nḓivho ya ngudo iyi yo vha i ya u sedzulusa masiandoitwa a mupo na khombo dza mushumo wa u vusuludzwa ha mathukhwi o khwaṱhaho kha vhadobeli vha mathukhwi ngei Goudkoppies Landfill Site khaḽa Soweto, hune ha vha na vhadobeli vha mathukhwi vha ṱoḓaho u swika 2 000. Ngudo iyi yo shumisa nḓila yo ṱanganaho ya u kuvhanganya muvhigo, nga nḓivho ya u nanga vhathu vho ḓidzhenisaho kha inthaviyu vha 17 na u khetha mbudziso dza 152 dzo ṋetshedzwaho nga vhane vha kuvhanganya mathukhwi, vhaofisiri vha fhethu hu no laṱiwa mathukhwi, na vhaṋe vha senthara dza u renga murahu mathukhwi kana vhalanguli vhahone. Data yo dovha ya kuvhanganywa nga kha u ṱola fhethu ha u laṱelwa mathukhwi. Data ya vhuimo yo ṱoḓisiswa nga zwanḓa na nga nḓila ya u ṱuṱuwedza ngeno Data ya tshivhalo yo senguluswa hu tshi shumiswa Phasela ya Zwisiṱatistiki ya Saintsi ya Matshilisano ane sia ḽavha 2.9 (SPSS). Mvelelo dzo sumbedza uri u dobela mathukhwi zwo shela mulenzhe nga nḓila yavhuḓi nga u vhuisa zwishumiswa zwine zwa nga shumiswa hafhu, u tikedza u kunakisa hu bveledzaho ha mupo, na u engedza vhutshilo ha fhethu ha u laṱela mathukhwi. Fhedziha, u vusuludzwa ha fhethu hune ha laṱiwa hone mathukhwi zwo vha na masiandoitwa mavhi kha mupo, hu tshi katelwa na u laṱekanya mathukhwi, khombo ya mulilo na maitele a u dobedza mathukhwi a songo tsireledzeaho. Vhathu vhane vha kuvhanganya mathukhwi vho dovha vha bviselwa khagala nga khombo dza u dobela mathukhwi dzi ngaho munukho u vhaisaho, tshikafhadzo ya phosho, malwadze a u fema, u tsheiwa nga ngilasi na u ṱangana na zwiḽiwa zwine zwa vha na mulimo. Hezwi zwiimo zwo ita uri fhethu hune ha laṱiwa hone mathukhwi hu vhe fhethu hu si havhuḓi ha u shuma, nahone mutakalo na matshilo a vhane vha vusuludza mathukhwi a khomboni.; Ku hlengeletiwa ka switirhisiwa leswi nga tirhisiwaka hi vuntswa eswivandleni swo lahlela malakatsa eka swona swi nga va na switandzhaku swa kahle na swo biha, tanihi laha switirhisiwa leswi swi tekiwaka swi ri swa nkoka ni ku tlhela swi hlayisa vaakatiko va miganga leyi nga le vuswetini. Hambiswiritano, vanhu lava tirhaka ku rholela malakatsa ya switirhisiwa va ti kuma va ri vari khombyeni ro khomiwa hi mavabyi yo hambana hambana, va nga ti kuma va khome swilo leswi nga na khombo swin'we ni swiphiqo swin'wana leswi va nga hlanganaka na swona hi ku khoma minchumu leyi. Xikongomelo xa ndzavisiso lowu a ku ri ku kambela switandzhaku leswi nga va ka kona eka mbango xikan’we ni makhombo lawa fambelanaka na ku tlhela ku hlengeletiwa switirhisiwa leswi exivandleni xo lahlela malakatsa xa Goudkoppies eSoweto, laha ku nga ni vanhu va kwalomu ka 2 000 lava rhwalelaka rholela malakatsa ya switirhisiwa. Ndzavisiso lowu wu tirhisile maendlelo yo hlanganisa mindzavisiso yo hambana hambana hambana-hambana, laha ku hlawuriweke 17 wa vanhu lava va nga vutisiwa swivutiso swa mayelana na ndzavisiso naswona 152 wa swivutiso swa nkambisiso lowu hleriweke (ku nga phepha ra swivutiso) wu nyikiwile vanhu lava tirhaka ku rholela malakatsa ya switirhisiwa, vatirhi va le swivandleni leswi swa malakatsa, xikan’we na vafambisi lava tirhaka hi ku xavisa switirhisiwa leswi nga tirhisiwaka hi vuntswa kumbe valawuri va swivandla leswi. Ndzavisiso wu tlhele wu endliwa hi ku tirhisa endlelo ra vuxiyaxiya bya swiendlo swa vanhu lava tirhaka ku rholela malakatsa ya switirhisiwa eka xivandla lexi xo lahlela malakatsa. Endlelo ra ndzavisiso wa nkoka wu hleriwile handle ko tirhisa switirhisiwa swa nkambisiso naswona mindzavisiso ya ntalo yi hleriwile hi ku tirhisa xitirhisiwa xa Statistical Package for the Social Sciences (SPSS) xa nkandziyiso wa 2.9. Mimbuyelo ya ndzavisiso lowu yi kombisile leswaku swi kahle ku rholela malakatsa ya switirhisiwa leswi nga tirhisiwaka hi vuntswa, na ku hlayisa no basisa mbango, xikan’we no tiyisisiwa vumundzuku lebyi faneleke bya swivandla leswi swo lahlela malakatsa ya switirhisiwa. Hambiswiritano, ku tlhela hi hlengeleta malakatsa ya switirhisiwa leswi nga lahliwa swi na mimbuyelo yo biha eka mbango, leswi katsaka ku vanga thyaka, makhombo ya ndzilo xikan’we na mixungeto leyi nga va ka kona hikokwalaho ko hlengeleta switirhisiwa handle ko tirhisa vurhon’wana. Vanhu lava va tirhaka ku rholela malakatsa ya switirhisiwa va tlhele va langutana ni makhombo yo hlangana ni risema leri nga tsakisiki, ni mpongo pongo ra switirhisiwa, ni mavabyi lawa fambelanaka na ku hefemula, va tsemiwa hi tinghilazi na ku ti kuma va dyile swakudya leswi nga ni chefu. Swiyimo leswi swi endlile leswaku swivandla leswi ku lahliwaka malakatsa ya switirhisiwa eka swona swiva swivandla leswi nga hlayisekangiki naswona swi va swi ri swiri na khombo lerikulu eka rihanyo ni vutomi bya vanhu lava tirhaka ku hlengeleta switirhisiwa leswi nga tirhisiwaka hi vuntswa. Abstract in English, Venda and Tsonga

2025-08-01T00:00:00Z Kidwai, Zaara https://ir.unisa.ac.za/handle/10500/31975 2024-11-28T13:48:21Z 2023-12-01T00:00:00Z

Ungulate communities and the role of environmental gradients in their spatial and temporal dynamics Kidwai, Zaara The African savanna supports a high diversity of ungulate species that have intrigued scientists for a long time. Fluctuating densities across space and time suggest ungulate populations are predominantly regulated by climatic conditions. In South Africa, most conservation areas are relatively small and likely impose limitations to resource acquisition by ungulates. The rationale of this thesis is to explore the variables causing population fluctuations in co-existing species, along with understanding the difference in their spatial distribution and segregation patterns in the North-West province of South Africa. The study includes 17 years (1999-2015) of data collected across 13 protected areas via aerial surveys during the dormant season. I used N-mixture models to improve estimation of population abundance of a rare species (black rhino) from replicated aerial surveys while accounting for imperfect detection. Generalized linear models and spatial occupancy models were used to determine factors affecting distribution and habitat partitioning of ungulates across the landscape. Ungulate habitat selection and occupancy was predominantly influenced by topography. For example, low-lying habitats were favoured by most ungulates during the dry season, probably because of the longer retention of soil moisture and higher forage quantity in areas lower down the catena during the dormant season. High heterogeneity in turn, were more important to mixed and bulk feeders e.g. impala, zebra. Spatial occupancy of ungulate groups was not directly related to the species richness in a feeder group. Pilanesberg had the lowest occupancy of all three groups despite having the highest number of species suggesting spatial avoidance or resource partitioning within each group. Spatial segregation was highest in sites with the highest species diversity. Within-group spatial segregation occurred within all three groups between similar sized along with between species of varying body size across 6 all sites except Molopo. Species interactions within ungulate assemblages are complex and varies with changing environmental conditions. For the effective conservation of ungulate populations, the specific ecological context needs to be considered. Additional ecological factors e.g., predation, resource availability and management variables e.g., fire, water availability and fences are equally important influences on the viability of ungulate populations of small fenced conservation areas.

2023-12-01T00:00:00Z Ndlovu, Sithabile Sharon https://ir.unisa.ac.za/handle/10500/31966 2024-11-28T13:57:12Z 2024-01-26T00:00:00Z

Exploring the use and influence of macronutrients and energy information labelling on the intention to purchase packaged food Ndlovu, Sithabile Sharon The high prevalence of obesity in South Africa has been linked to unhealthy food consumption. Food labelling plays a significant role in informing and educating consumers about macronutrients in the food they consume. Despite the proven efficacy of food labelling, a dearth of research exists on consumers’ understanding and use of macronutrient and energy information labelling and how this information influences consumers’ intention to purchase packaged food products. A qualitative interpretative phenomenological study was conducted, and purposive, convenience, and snowball sampling was used to select participants who were food label readers. Virtual interviews were held to collect data, and content analysis of the findings suggest that a significant number of participants were aware of macronutrients and energy information labelling. However, their inability to interpret the macronutrients and energy information labelling negatively affected their use of this information, influencing their purchase intention of the food products. Future research can focus on the development of an educational programme to facilitate consumers’ knowledge and understanding of macronutrients and energy information labelling.; Ukudlondlobala kwenani labantu abakhuluphala ngokweqile eNingizimu Afrika kuhlobene nokusetshenziswa kokudla okungenampilo. Ukunamekwa kwemibhalo ekudleni kudlala indima enkulu ekwaziseni nasekufundiseni abathengi mayelana nezakhamzimba ekudleni abakudlayo. Ngaphandle kwemiphumela emihle ekunamekweni kwemibhalo ekudleni, lusasilele ucwaningo lokuqonda nokusebenzisa imibhalo enamekwe ekudleni nokudla izakhamzimba ngokunjalo nokuthi ngakube le mibhalo inamuphi umthelela kubathengi uma bethenga imikhiqizo yokudla. Lapha kusetshenziswe ucwaningo lokuhlola iqophelo, inhloso, ukwaneliseka, kanye nokunxenxa abanye ukuze kutholakale ababambiqhaza abavame ukufunda izinameko ezisekudleni. Imininingwane iqoqwe ngokubanjwa kwezinkulumongxoxo, kanye nokuthi ukucwaningwa kwengqikithi yemiphumela etholakele kuveza ukuthi inani elikhulu lababambiqhaza linolwazi mayelana nezakhamzimba kanye nokunamekwa kwemibhalo ekudleni. Kodwa-ke, ukuhluleka kwabathengi ukuhumusha imininingwane ngezakhamzimba nokunamekwa kwemibhalo ekudleni kwenza ukuthi bangakwazi ukusebenzisa kahle le mininingwane, kuphinde kuphazamise izinhloso zabo ekuthengeni imikhiqizo yokudla. Ucwaningo lwesikhathi esizayo lungagxila ekuqalisweni kohlelo lokufundisa ukuze abathengi babe nolwazi futhi baqondisise kahle ngezakhamzimba kanye nokunamekwa kwemibhalo ekudleni.; Ukuxhaphaka jikelele okuphezulu kokutyeba eMzantsi Afrika kuye kwanxulunyaniswa nokutya okungekho sempilweni. Ukuphawulwa kokutya (food labelling) kudlala indima ebalulekileyo ekwaziseni nasekufundiseni abathengi ngeezondlo ezidingwa ngumzimba ekutyeni abakutyayo. Ngaphandle kokusebenza okuqinisekisiweyo kokuphawulwa kokutya, ukunqongophala kophando kukhona malunga nokuqonda kwabathengi kunye nokusetyenziswa kolwazi olubhaliweyo ngeezondlo ezinkulu namandla kunye nendlela olu lwazi oluchaphazela ngayo iinjongo zabathengi zokuthenga iimveliso zokutya. Kusetyenziswe uphando lophandontyilazwi oluchaza indlela izinto ezingayo ngokwamava abantu, kukwasetyenziswe iindlela zokukhetha idatha ezifana nokukhetha igcuntswana ledatha ngenjongo, ukukhetha igcuntswana ledatha elifumaneka lula, kunye nokukhetha igcuntswana ledatha ngokufumaneka nzima ngokuncedwa leloo gcuntswana ledatha elisele likho ukukhetha abathathinxaxheba abafunda iileyibhile zokutya. Kubanjwe udliwanondlebe olubanjwa ngezobuchwepheshe ukuqokelela idatha, kwaye uhlalutyo lomxholo weziphumo lubonisa ukuba abathathinxaxheba abaninzi bayayazi ngokubhalwa kolwazi lweezondlo ezidingwa ngumzimba namandla. Nangona kunjalo, ukungakwazi kwabo ukutolika ukubhalwa kolwazi lweezondlo ezidingwa ngumzimba namandla kuyichaphazele kakubi indlela abalusebenzisa ngalo olu lwazi, kuchaphazela iinjongo zabo zokuthenga iimveliso zokutya. Uphando lwexesha elizayo lunokugxila ekuphuhliseni inkqubo yemfundo yokuququzelela ulwazi nokuqonda kwabathengi kokubhalwa kolwazi lweezondlo ezidingwa ngumzimba namandla Abstracts in English, Zulu and Xhosa

2024-01-26T00:00:00Z