Leaded fuel has been reported to contain certain amounts of toxic trace metals such as Pb and Cadmium (Cd), which may have negative impacts on humans and the environment. Unleaded fuel was introduced to South Africa in 2006 with the aim of reducing and eventually eliminating the negative impact of leaded fuel on the environment. However, trace metals are usually nonbiodegradable, and it may therefore be necessary to monitor their presence in the environment so as to evaluate their possible impact on human health. The present study evaluated the levels of Pb and other heavy metals in soil samples collected from petrol (gas) filling stations and from busy roads just around the filling stations in Pretoria, South Africa, fifteen years after the introduction of unleaded fuel. A total of twenty-four (24) soil samples were analysed for lead (Pb), chromium (Cr), copper (Cu), zinc (Zn), arsenic (As), iron (Fe), manganese (Mn), nickel (Ni), titanium (Ti), and cadmium (Cd) using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results showed that the concentrations of the trace metals were in the following ranges: Pb, 0.08 ± 0.02–188.36 ± 15.32 ug/g; Mn, 5.35 ± 0.34–6842.43 ± 1.35 ug/g; Zn, 1.82 ± 0.22–9814.89 ± 22.32 ug/g; As, 0.21 ± 0.00–8.42 ± 2.44 ug/g; Cu, 10.51 ± 3.41–859 ± 0.09 ug/g; Cr, 5.80 ± 2.21–417.70 ± 9.08 ug/g; Ti, 19.94 ± 4.99–1036.12 ± 1.49 ug/g; and Fe, 3.06 ± 7.87–674.07 ± 12.22 mg/g. The highest concentrations from all the elements were recorded for Fe in all the collected soil samples. The concentrations of Pb in the soils collected from sites associated with high traffic and industrial areas were higher than for those from all other sites, and the differences were significant (p < 0.05). The pollution index (PI), which is the anthropogenic influence of the trace metals, and the geoaccumulation (Igeo), which allows for the removal of possible variations as regards the studied element in the soil due to the possible differences in the background value, showed that some samples were enriched anthropogenically. The PI for Ni, Pb, Cu, and Cr indicated highly anthropogenically contaminated soils, especially at sites associated with high traffic volumes and in industrial areas. The Igeo showed moderately polluted areas for Pb and Cu in high-traffic areas. The exposure routes for the toxic trace metals that were of concern in the study were either through ingestion or dermal contact. The calculated hazard quotient showed both noncarcinogenic and carcinogenic risks for Fe and Mn via ingestion and through dermal contact for both children and adults, respectively. The concentrations of Pb were high and similar to those that were previously reported in the study and pointed to vehicular emission as one of the contributors. The study also noticed an increase in the presence of Mn and Fe in all soil samples.

Trace metals have been reported in the literature to be associated with obesity. Exposure to some trace metals such as Mn, Cr, Ni, Cd, and Pb may pose a serious health risk to individuals living around a polluted environment. The present study assessed the levels of trace metals in the blood of obese females living around industrial areas in Gauteng, South Africa. The study was carried out using a mixed method approach. Only females with a BMI ≥ 30.0 were considered. A total of 120 obese females participated in the study (site 1: 40—industrial area, site 2: 40—industrial area, and site 3: 40—residential area), aged 18–45 and not in menopause. Blood samples were analysed for trace metals content using inductively coupled plasma mass spectrometry (ICP-MS). The mean concentrations of trace metals were in the order Pb > Mn > Cr > Co > As > Cd (site 1), Pb > Mn > Co > As > Cd (site 2), and Mn > Cr > Co > As > Pb > Cd (site 3). The blood Mn from site 1 ranged from 6.79 µg/L–33.99 µg/L, and the mean differences obtained from the participants from different sites were significant (p < 0.01). The blood levels of Mn, Pb, Cr, Co, As, and Cd were above the recommended limits set by the WHO in some of the participants. The present study noted, among others, closeness to industrial areas, lifestyle decisions such as the use of tobacco products by their partners indoors, and the method used for cooking as factors that might have accounted for the blood levels of Mn, Pb, Cd and Co. The study showed that there is a need for constant monitoring of the levels of trace metals in the blood of those living in these areas.