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Laportea peduncularis is a medicinal plant consumed by the native communities in South Africa. Due to its oral consumption, its potential for harming the human health and the distribution of metals in the leaves of L. peduncularis as a function of soil characteristics were evaluated. Broadly, the concentrations of metals in the soil were in decreas...
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... Soil samples were systematically gathered from the fifteen designated sites within the study area, adhering to a refined sampling protocol adapted from Mahlangeni et al. [28]. At each site, approximately 500 g of soil was extracted from a depth of 15 cm and secured in individually labelled zip-seal polyethylene bags to prevent contamination. ...
This research quantifies the health risks associated with exposure to heavy metals in the Matjhabeng Local Municipality, a gold mining region in South Africa, utilising a deterministic source–pathway–receptor approach. This study uniquely integrates both non-carcinogenic and carcinogenic risk assessments across multiple heavy metals, providing a comprehensive perspective on health impacts in mining-impacted communities. The study measured concentrations of arsenic (As), cadmium (Cd), lead (Pb), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), selenium (Se), and zinc (Zn) in soil samples, with mean values found to be 3.2 mg/kg, 2.5 mg/kg, 45 mg/kg, 17 mg/kg, and 25 mg/kg for As, Cd, Pb, Co, and Cr, respectively. The deterministic assessment revealed minimal non-carcinogenic risks for ingestion across all demographics (HQ < 1), while significant dermal risks were identified for Cd, Pb, Co, and Cr (HQ > 1), particularly for the adult group. The inhalation pathway emerged as a critical exposure route, with HQ values ranging from 5 to 15 and chronic hazard index values significantly exceeding safe limits (CHI > 5). The carcinogenic risk through inhalation notably surpassed the acceptable thresholds set by the United States Environmental Protection Agency (1 × 10−4 to 1 × 10−6), with a calculated lifetime cancer risk far exceeding the limit for As, Cd, Cr, Co, and Ni for both adults and juveniles. These findings underscore the urgent need for targeted risk mitigation strategies in the community to address the significant health risks posed by airborne heavy metal exposure.
... Therefore, the legacy gold mine tailings and active mining activities in the area are likely the primary sources of pollution in the MLM area. The PCA results obtained in this study revealed closely similar results for PC1 and PC2 in a study conducted in KwaZulu-Natal, South Africa [66]. This contamination of surface water bodies by PTEs poses a severe risk to aquatic organisms and the local community in the MLM area. ...
This study focused on assessing the extent of pollution in both flowing and non-flowing surface water within the Matjhabeng mining area of South Africa, with particular emphasis on the substantial impact of gold mine tailings. A comprehensive analysis of physical water-quality attributes, including potentially toxic elements (PTEs), and relevant pollution risk indices was undertaken. To comprehensively elucidate the potential risks to aquatic organisms and human health, a risk assessment framework predicated upon the source–pathway–receptor model was developed. Principal Component Analysis (PCA) was employed as a multivariate statistical tool to discern the potential origins of PTE contamination within the environment. The results substantiate pronounced pollution manifestations within the surface water milieu of the Matjhabeng mining area. Specifically, concentrations of critical PTEs, such as arsenic, cobalt, copper, iron, selenium, and zinc, exhibited transgressions of the regulatory thresholds stipulated by both the South African Department of Water Affairs and Forestry (DWAF) and the Canadian Council of the Ministers of the Environment (CCME). Additionally, concentrations of the aforementioned elements exceeded the stipulated DWAF guidelines for irrigation water usage. Pollution indices, encompassing the Single-Factor Pollution Index and the Nemerow Integrated Pollution Index, discerned moderate contamination stemming from As, while remarkably elevated pollution levels were identified for selenium. PCA elucidated 94.5% of the aggregate variance, revealing cobalt, copper, nickel, and zinc as coalescing within PC1, indicative of a common anthropogenic provenance that is conceivably linked to historical gold mine tailings. PC2 exhibited an aggregation of chromium, iron, and lead, reaffirming this shared anthropogenic etiology. The third PCA component was characterized by selenium, followed by arsenic and magnesium in the fourth. The resultant PTE contamination underscores a profound ecological and public health risk, impacting both the aquatic ecosystems and the local community within the precincts of the Matjhabeng Local Municipality (MLM) area, with consequential amplification of susceptibilities to deleterious health consequences. Urgent and concerted interventions are imperative to ameliorate the emergent decline in surface-water quality within the MLM locale. The adoption of nature-based remediation paradigms holds promise for efficaciously elevating water quality, ameliorating community health, and underpinning the long-term economic viability of the region.
... The plant leaf samples were washed with double distilled water and then after, the soil and plant leaf samples were dried in an oven at 60 C for 48 hours. [22] The dried soil and plant leaf samples were ground in a porcelain mortar using a pestle and sieved through a 2 mm silicon handler stainless steel sieve. [22] The samples were packaged into separate zip-sealed plastic bags and stored in the refrigerator at 4 C, to prevent further microbial activities, which may affect the different physicochemical properties in the soil before analysis. ...
... [22] The dried soil and plant leaf samples were ground in a porcelain mortar using a pestle and sieved through a 2 mm silicon handler stainless steel sieve. [22] The samples were packaged into separate zip-sealed plastic bags and stored in the refrigerator at 4 C, to prevent further microbial activities, which may affect the different physicochemical properties in the soil before analysis. [23] Measurements Measurement of soil pH and conductivity The pH of the soil was measured to determine the level of acidity and alkalinity of the soil. ...
... [24] The pH and conductivity measurements were determined in triplicates by preparing a mixture of soils and distilled water in a 1:2.5 ratio. [22] The pH was then measured using a Mettler Toledo 51302070 pH meter, while conductivity of the soil was measured using a Mettler Toledo S23030019034 Conductivity Meter (Mettle Toledo, Sandton, Pretoria, South Africa). ...
The presence of potentially toxic elements (PTEs) in soil and plants is a risk factor to human well-being and the environment. Soil and leaves from a traditional medicinal plant, Vachellia karroo, known as the sweet thorn plant, were assessed to determine the extent of pollution by PTEs from gold mine tailings in a case study area of Matjhabeng Local Municipality, South Africa. A risk classification tool was developed using the different indicators of pollution quantified to describe the pollution risk at each sampling site. High concentrations of copper, cadmium, lead, nickel, and zinc were measured in the soil, which exceeded the maximum permissible soil quality limits. The enrichment factor and geoaccumulation index results also confirmed heavy soil pollution by copper, nickel, and zinc, with exceptionally heavy pollution by cadmium and selenium. The PTEs in the soil were in an exchangeable form, with the sweet thorn plant accumulating lead and selenium at toxic levels, which poses a risk to the health of the local people as the plant is used for medicinal purposes. The overall pollution risk classification tool of the sampling sites showed that 17% were high-risk areas, 53% were moderate-risk areas, and 20% of the sites were low-risk areas.
... The EF values of Pb in soil and sediment samples are shown in Figure 3. Aluminum, the most common reference value used to calculate the EF, was selected to be the The EF values of Pb in soil and sediment samples are shown in Figure 3. Aluminum, the most common reference value used to calculate the EF, was selected to be the normalizing element [45,46], with the values for the samples provided in Table A1 (Appendix A). EF has been widely used to quantify the degree of metal enrichment or contamination in soils and sediments samples due to human activity [60][61][62]. As was the case in the Igeo analysis, sites S1 and S2 were categorized as having "extremely high enrichment", for both soils and sediments. ...
... normalizing element [45,46], with the values for the samples provided in Table A1 (Appendix A). EF has been widely used to quantify the degree of metal enrichment or contamination in soils and sediments samples due to human activity [60][61][62]. As was the case in the Igeo analysis, sites S1 and S2 were categorized as having "extremely high enrichment", for both soils and sediments. ...
... The rest of the samples were categorized as having "significant enrichment" (Class 3) or higher. It's important to note that values above 1.5 suggest anthropogenic origin [60][61][62]. ...
Lead (Pb) contamination was evaluated in 24 contaminated soils and sediments samples, representative of areas affected by mining, agricultural, commercial and residential activity, during the rainy and dry season. Pseudo-total concentration in soils (15.7–527.2 mg kg−1) and sediments (16.3–4273.3 mg kg−1) was determined and protocols were developed to analyze its chemical form, potential mobility and bioavailability. Five geochemical phases (exchangeable fraction, carbonate fraction, Fe/Mn oxide fraction, organic fraction and residual fraction) were obtained for the determination of Pb speciation and mobility using a modified Tessier sequential extraction procedure. The predominant fraction was the Fe/Mn oxide bound (both for soils and for sediments). However, their calculated mobility factors were 26% and 28%, respectively, representing significant risk to the environment. Geo accumulation values ranged from −0.7 to 4.4 (“Unpolluted”–“Highly to extremely polluted”) for soils and from −0.6 to 7.4 (“Unpolluted”–“Extremely polluted”) for sediments, suggesting the influence of human activity on the environment, mainly at sites located in the vicinity of the mine. Enrichment Factor values ranged from 2.1 to 87.8 for soils and from 2.5 to 698.7 for sediments (“Moderated enrichment”–“Extremely high enrichment”); values above 1.5 suggesting anthropogenic origin, thus representing a risk for biological organisms present in freshwater. In summary, these environmental indicators demonstrated than even in sites with low Pb concentration, contamination was observed, thus highlighting the need for continued monitoring due to the potential for significant public health risks.
... The microwave-assisted closed-vessel method was used to digest the dry fruit, soil, and certified reference material (CRM) samples. Digestions were performed using the CEM Microwave Accelerated Reaction System (MARS) 6, (CEM Corporation, Matthews, NC, U.S.A) with patented MARSXpress Plus TM as per the method described by Mahlangeni et al. [23] Digests were filtered into 25 mL volumetric flasks, diluted to the mark with double-distilled water and stored in polyethylene bottles at 4 C prior to elemental analysis which was up to one week later. All digestions were performed in triplicate. ...
Carpobrotus dimidiatus is an indigenous South African medicinal plant species from the Aizoaceae family that bears edible fruit that is consumed for nutritional value. In this study, the elemental distribution in C. dimidiatus fruit and growth soil from fifteen sites in KwaZulu-Natal (South Africa) was determined along with soil pH, soil organic matter and cation exchange capacity, to assess for nutritional value and the effect of soil quality on elemental uptake. The results showed elemental concentrations in fruit to be in decreasing order of Ca (6235–32755 mg kg⁻¹) > Mg (2250–5262 mg kg⁻¹) > Fe > Mn > Zn (20.9–50.6 mg kg⁻¹) > Cu (3.83–20.6 mg kg⁻¹) > Pb > Cr > Cd > As ∼ Co ∼ Ni ∼ Se and no potential health risk due to metal toxicity from average consumption. For sites that had high levels of Cd and Pb, bioaccumulation occurred from atmospheric deposition. Concentrations of elements in soil were found to be in decreasing order of Fe (1059–63747 mg kg⁻¹) > Ca (1048–41475 mg kg⁻¹) > Mg > Mn (9.76–174 mg kg⁻¹) > Cr (1.55–135 mg kg⁻¹) > Zn (0.76–58.2 mg kg⁻¹) > Se > Cu > Ni > Pb > Co > As ∼ Cd with no evidence of heavy metal contamination. This study revealed that the plant inherently controlled uptake of essential elements according to physiological needs and that the concentrations of essential elements in the fruit could contribute positively to the diet.
... Previous studies have reported on the elemental distribution in edible plant species found in South Africa as a function of soil quality (Mngadi et al. 2016;Moodley et al. 2012;Mahlangeni et al. 2016). In this study, we investigate the distribution of metals in M. zeyheri fruits collected from various sites in Gauteng and North West Province, South Africa. ...
... On average, 35% of Mg in the soil was in available form with high amounts accumulated by the plant (BAFs ranging between 2.2 and 20.7%). High BAFs observed for Ca, Mg and Na show that the plant has a tendency to accumulate these elements to meet physiological requirement levels, similar to other studies, with the exception of sites A and D, where Na concentration was higher (Mngadi et al. 2017;Mahlangeni et al. 2016;Moodley et al. 2009). ...
Mimusops zeyheri is widely used in traditional medicine and for nourishment. Consequently, the elemental composition, including heavy metals concentrations in M. zeyheri fruits, sampled from industrial and mining areas in Gauteng and North West Province, South Africa, was determined. The results showed soil concentrations to be in decreasing order of K > Na > Ca > Mg > Fe > Al > Zn > Mn > Cu > Cr > Sr > Pb > As > Li > Ni ≈ Co > Rb > U > Bi > Ga > Be > Tl > Mo > Ba > Ag > Cd. Geoaccumulation indices showed moderate contamination by Cd that did not accumulate in the fruits whilst principal component analysis revealed metals in soils to originate from different anthropogenic sources in the area. The plant controlled uptake of metals to meet metabolic needs and levels of toxic metals was low making the fruits suitable for human consumption, even if picked from sites close to mining areas. Nutritional value of the fruits highlighted their positive contribution to the diet and showed them to be rich in Cr and Mn.
... Previously, we reported on the distribution and bioaccumulation of metals in edible medicinal plant species and the river, stinging and mountain nettles (Jonnalagadda et al. 2008;Mahlangeni, Moodley, and Jonnalagadda 2012, 2016a, 2016b. In this study, we report on the concentration of elements in the forest nettle (Laportea alatipes Hook. ...
... Both plant and soil digestions were performed using the Microwave Accelerated Reaction System (MARS 6: CEM Corporation, Matthews, NC) with patented Xpress Plus Technology according to method as described by Mahlangeni, Moodley, and Jonnalagadda (2016a). Plant and soil samples (0.25 g) were digested with 70% HNO 3 (10 mL). ...
Elements found in the edible parts of plants are considered to be the main source of nutrients for humans and animals. However, there is insufficient information on the relationship between heavy metal pollution in the growing soil of most edible plants. In this study, the distribution of elements in the edible forest nettle (Laportea alatipes) was evaluated as a function of geographical location. Forest land soils had higher concentrations of minor elements (Cu, Cr, Ni, and Zn) compared to soils from rural and suburban areas. Translocation factors for Cd and Pb showed effective translocation from the roots to the leaves; however, these heavy metals in leaves were still above South African maximum permissible levels for vegetables. Atmospheric depositions may play a significant role in higher Cd and Pb concentrations in the leaves. Bioaccumulation factors showed the plant to accumulate Cu, Mn, and Zn to meet physiological requirement levels. Geoaccumulation indices and enrichment factors showed no soil contamination or minimal enrichment by trace metals. Principal component analysis showed Co, Cr, Cu, Fe, Ni, Pb, and Zn in soil to originate from a common source which may be soil silicates and other minerals.
... Trifolium dubium accumulated Mg which was indicated by high BAFs at most sites. Bioaccumulation factors for Ca and Mg indicated that the plant tended to accumulate these macroelements to meet physiological requirement levels, which has been reported in previous studies (Mahlangeni, Moodley, and Jonnalagadda 2016b). Sites E, G, and H were the only sites that exceeded the maximum permissible levels for Mg in South Africa soils (1300-1500 mg kg À1 ) (Guo et al. 2016). ...
Trifolium dubium is an edible plant that is utilized in traditional medicine for its anti-inflammatory and wound-healing properties. In this study, T. dubium was assessed to determine the elemental uptake by the plant as a function of soil characteristics. Across 10 geographic locations in KwaZulu-Natal, South Africa, the concentration of elements in T. dubium were found to be (descending order) Ca > Mg > Fe > Zn > Mn > Se > Ni > Cr > Cu > Co > Pb > Cd > As. The site had an influence on elemental uptake by the plant; however, accumulation or exclusion of elements from soil was controlled to meet physiological requirements. Soil chemical characteristics showed T. dubium grew in slightly acidic soils (pH – 6.15 to 6.68). The findings of this study show T. dubium to contain adequate concentrations of essential elements with undetectable levels of toxic metals, making the herb safe for human consumption and for use in traditional medicine. The plant can also contribute to poor communities by ameliorating food insecurity.
... 5 Although the copper ion is as essential element for plant growth and human health, an excessive amount of copper may be harmful to plants, animals, and humans. [6][7][8] Thus, to avoid too much copper intake, it is essential to establish an accurate, sensitive, highly effective, and low cost method for timely monitoring the concentration of Cu 2+ ion in environmental and food samples. ...
Two novel isomeric colorimetric probes are established for simultaneous determination of copper ions using 2-hydroxy-5-methoxybenzaldehyde fluorescein hydrazone (5-HMBA-FH) and 2-hydroxy-3-methoxybenzaldehyde fluorescein hydrazone (3-HMBA-FH). They are synthesized by reacting fluorescein hydrazide with 2-hydroxy-5-methoxybenzaldehyde and 2-hydroxy-3-methoxybenzaldehyde, respectively, and then characterized by ¹H-NMR, ¹³C-NMR, and infrared spectrum. The addition of copper ions to the solutions of two novel colorimetric probes can generate the obviously peaks at 498 nm in UV–vis absorption spectra along with a rapid colour change from colourless to dark yellow. The detection limits of the method for Cu²⁺ ion were 3.442 × 10⁻⁶ mol/L and 3.682 × 10⁻⁶ mol/L separately for 5-HMBA-FH and 3-HMBA-FH, respectively. The additions of other metal ions hardly affect the determination of copper ions. The proposed method was successfully applied to the analysis of Cu²⁺ ions in various samples. This method possesses high sensitivity, high simplicity, and minimized interference and will provide a great advantage in detecting copper ions in the environment, food, and medical applications.
... Among the many substances that contaminate rivers and lakes, heavy metals are critical. They are not biodegradable and can have long-term toxic effects (Mahlangeni et al. 2016). Heavy metals in aquatic environments can originate from natural sources (e.g. ...
Streams in urban areas are strongly impacted by the input of organic matter and metals, for instance copper (Cu) and zinc (Zn). These metals are essential for the aquatic biota, but when absorbed in excess they are toxic. In Chironomidae larvae, the deleterious effects of heavy metals can be ascertained by analyzing the morphological deformities of the larval mentum, a structure of the oral cavity. In this study, we evaluated I) the bioavailability of Cu and Zn in urban stream sediments and II) the relationship between Cu and Zn concentrations and the incidence of deformities in the mentum of Chironomus larvae. Chironomid flies were collected from four locations in two streams at an urban area in southern Brazil. They were identified and the incidence of deformities in the mentum was quantified. Sediment samples were collected at the same locations where larvae were collected, to quantify the bioavailable fractions of Cu and Zn. The concentrations of Cu in the sediment were similar between the collection sites. However, Zn concentrations varied among sites, being greater in the stretch directly influenced by the input of the organic waste. In total, 2,895 Chironomid larvae were collected. The incidence of deformities in the mentum was above 30% and was correlated with the concentrations of Cu (r = 0.68) and Zn (r = 0.87). This correlation indicates that the municipal waste that is thrown into the city’s streams has influenced the occurrence of deformities.
