Potential ecological and health risks of toxic metals associated with artisanal mining contamination in Ijero, southwest Nigeria

Assessment of heavy metals and human health risk associated with the consumption of crops cultivated in industrial areas of Maputo, Mozambique

This study aimed to evaluate heavy metals concentrations in soils and vegetables (cabbage, lettuce, and cassava) cultivated at Matola and Beluluane Industrial Parks, and to assess health risks linked to their consumption through estimated daily intake, hazard index (HI), and incremental lifetime cancer risk. Concentrations of Al, As, Co, Cd, Cr, Ni, Pb, and Zn were determined in the two sites. Soil concentrations of As at Beluluane site and As, Cd, and Cr at Matola site exceeded reference limits of the Food and Agriculture Organization/World Health Organization, showing heavy metal contamination. At Beluluane site, all studied vegetables presented As and Pb levels higher than reference limits, Cd concentrations were higher than the reference limit in cabbage, lettuce, and cassava leaves. At Matola site crops concentrations of As, Cd, Cr, and Pb exceeded the reference limits. Zinc exceeded the reference limit in all crops except in cabbage. HIs for vegetables from Beluluane exceeded 1.0 in cabbage (2.66), lettuce (2.27), and cassava leaves (2.37). Likewise, at Matola, HIs exceeded 1.0 in lettuce (1.67), cassava leaves (1.65), and root tubers (13). We found that vegetables cultivated in industrial parks present high carcinogenic risk due to heavy metal contamination, rendering them unsuitable for human consumption.

Artisanal Gem Mining in Brazil: A Source of Genotoxicity and Exposure to Toxic Elements

Environmental and occupational exposure to toxic metals has led many people around the world to have serious health problems. Mining activities contribute to an increased risk of exposure to these elements. In this work, a study of environmental biomonitoring and routes of exposure to toxic metals in a region of artisanal mining was performed. This study was carried out in the district of Taquaral de Minas, located in the Jequitinhonha Valley in the state of Minas Gerais. The valley is one of the wealthiest and highest gem-producing areas in Brazil. Five artisanal mines were sampled (Bode, Pirineu, Pinheira, Lajedo, and Marmita). Several potentially toxic metals (Be, Zn, Mn, Ba Cd, Hg, and U) were investigated in the soils and dust over the rocks and the soils. Samples from 22 individuals occupationally exposed and 17 unexposed persons, who formed the reference group, were analyzed for trace elements by an inductively coupled plasma mass spectrometer. The genotoxicity was evaluated by the micronucleus test in buccal mucosa epithelial cells, where the following changes were scored: micronuclei (MN) binucleate (BN) cells and kariolytic (KL) cells. The MN test showed significantly increased frequencies in all alterations of exposed individuals compared to the controls (p < 0.05, Student's t-test). The urine analysis showed levels of Cr, Ni Ba, Pb, and As in the blood, which were higher than the ATSDR recommended levels. The association between the MN test and the trace element concentrations found in the blood and urine was significant (p < 0.05). The higher the number of years of working, the higher the concentrations in the blood were, due to chronic exposure. The results of the present study indicate environmental contamination and a potential risk to the health of miners, suggesting an intervention.

Assessment of Potentially Toxic Element Concentrations in Soil And Vegetables and Impact on Human Health Through TF, EDI, and HRI Indicators: Case Study Anadrinia Region (Kosovo)

Vegetable cultivation areas in the Anadrinia region may have higher than background concentrations of potentially toxic elements (PTEs) from contaminated sources including anthropogenic activity and lithologic composition. The purpose of the present study was to assess PTEs concentrations in soil and vegetables and their impact on human health. In this study, 50 soils and 5 vegetables were sampled from the studied area. PTEs (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) were measured by inductively coupled plasma optical emission spectroscopy (ICP-OES) after digestion in microwave system. PTEs in soil and vegetables were assessed and compared to international data (Dutch List and WHO/FAO 2011), and their toxicological risk was estimated using transfer factor (TF), estimated daily intake (EDI), and hazard quotients (HQ). The average values of As, Cd, Co, Fe, and Mn in soil were 44.96, 0.324, 16.34, 13,172, and 765.1 mg/kg, and Cr, Ni, and Pb in vegetables were 21.02, 17.11, and 4.982 mg/kg. TF values were less than 1, suggesting low bioaccumulation. EDI values of Cu, Ni, Pb, and Zn were 6.29, 6.23, 2.09, and 16.6 mg/kg, higher than international guidelines. HQ values of Pb, Ni, and Cu were 6.22, 3.66, and 1.72, higher than maximum tolerable value 1 indicating significant health risk. Some of the analyzed elements in soil and vegetable exceeded permissible limits to Dutch List and WHO/FAO 2011, respectively. From a health point of view, this study revealed vegetable contamination, recommends periodic monitoring.

Using pollution indices to develop a risk classification tool for gold mining contaminated soils

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.

Assessing the effect of working conditions on routine medical checkup among artisanal goldminers in Ghana

The socio-economic impacts of unforeseen health challenges among mine workers cannot be overemphasized. Due to the nature of artisanal mining in Ghana, workers are responsible for their own health care. This, however, necessitates the need for insight into the dynamics of self-care among artisanal miners. A cross-sectional survey of 500 artisanal gold miners was conducted to explore the relationship between working conditions of artisanal miners and voluntarily going for routine medical checkup, even in the absence of the right support systems, using a nested binary logistic regression. All the working condition variables were robust in predicting routine medical checkup in all three models. In this case, goldminers who reported good health, safety and environmental conditions were more likely to go for routine medical checkup as compared to their co-workers who reported poor health, safety and environmental conditions. Contrariwise, miners who reported good economic conditions were less likely to go for routine medical checkup as compared to their counterparts who reported poor economic conditions. Also, routine medical checkup was less likely among artisanal miners who did not protect themselves at work and had experienced work related health challenges. For the compositional factors, miners who had senior high school education were more likely to go for routine medical checkup as compared to those with no formal education. Likewise, older miners were more probable to go for routine medical checkup as compared to their younger counterparts. At the contextual level, miners who worked on shift regime and miners who worked in non-production departments were more likely to go for routine medical checkup. The outcome of this study provides insight into the dynamics of self-care amongst artisanal miners and how best to possibly improve it in an attempt to maintain a healthy workforce and its cascading effects. To increase consciousness of self-health care in artisanal mining, there is the need for a national dialogue on how to improve the working conditions of artisanal miners in Ghana.

Characteristics of heavy metals in size-fractionated atmospheric particulate matters and associated health risk assessment based on the respiratory deposition

The heavy metal distributions in size-fractionated atmospheric particulate matters and the associated health risks were investigated in a typical mining and smelting area in Southwest China. The Cd, Cr, Cu, Pb, and Zn concentrations were 19.28, 44.48, 100.0, 554.0, and 601.8 ng/m³, respectively, in PM_2.1; and 23.45, 60.99, 95.25, 559.3, and 813.7 ng/m³, respectively, in PM₁₀. Enrichment factors of heavy metals indicated that anthropogenic sources of Cd, Cu, Pb, and Zn in the size-fractionated particles. The elevated concentrations of Cd, Cu, Pb, and Zn were dominantly enriched in submicron particles (D_P < 1.1 μm), whereas Cr tended to be accumulated in coarse particles (2.1 < D_P < 10 μm). The deposition concentrations for multiple heavy metals in the head airway region, tracheobronchial region, and alveolar regions were 321.07, 21.58, and 51.96 ng/h for children, and 634.49, 42.65, and 102.68 ng/h for adults, respectively. The coarse particles contributed the most to the deposition concentration of HMs in head region, whereas submicron particles had relative higher proportions in the alveolar region. Heavy metals, especially Pb, caused noncarcinogenic risk to the children as the hazard index was 4.45. Moreover, total carcinogenic risks of heavy metals (Cr, Cd, and Pb) were 4.33 × 10^-5 and 7.58 × 10^-5 for adults and children, respectively, indicating potential carcinogenic risks. Overall, the results of this study revealed high health risks to the residents living around the mining and smelting areas, especially the children. It was therefore urgent to control the emission of heavy metals in the atmosphere.