Assessment of Total Mercury in Hair, Urine and Fingernails of Small-Scale Gold Miners in the Amansie West District, Ghana

Public health assessment of Kenyan ASGM communities using multi-element biomonitoring, dietary and environmental evaluation

The Kakamega gold belt's natural geological enrichment and artisanal and small-scale gold mining (ASGM) have resulted in food and environmental pollution, human exposure, and subsequent risks to health. This study aimed to characterise exposure pathways and risks among ASGM communities. Human hair, nails, urine, water, and staple food crops were collected and analysed from 144 ASGM miners and 25 people from the ASGM associated communities. Exposure to PHEs was predominantly via drinking water from mine shafts, springs and shallow-wells (for As>Pb>Cr>Al), with up to 366 µg L-1 arsenic measured in shaft waters consumed by miners. Additional exposure was via consumption of locally grown crops (for As>Ni>Pb>Cr>Cd>Hg>Al) besides inhalation of Hg vapour and dust, and direct dermal contact with Hg. Urinary elemental concentrations for both ASGM workers and wider ASGM communities were in nearly all cases above bioequivalents and reference upper thresholds for As, Cr, Hg, Ni, Pb and Sb, with median concentrations of 12.3, 0.4, 1.6, 5.1, 0.7 and 0.15 µg L-1, respectively. Urinary As concentrations showed a strong positive correlation (0.958) with As in drinking water. This study highlighted the importance of a multidisciplinary approach in integrating environmental, dietary, and public health investigations to better characterise the hazards and risks associated with ASGM and better understand the trade-offs associated with ASGM activities relating to public health and environmental sustainability. Further research is crucial, and study results have been shared with Public Health and Environmental authorities to inform mitigation efforts.

Application of machine learning techniques to predict groundwater quality in the Nabogo Basin, Northern Ghana

The main objective of this study was to map the quality of groundwater for domestic use in the Nabogo Basin, a sub-catchment of the White Volta Basin in Ghana, by applying machine learning techniques. The study was conducted by applying the Random Forest (RF) machine learning algorithm to predict groundwater quality, by utilizing factors that influence groundwater occurrence and quality such as Elevation, Topographical Wetness Index (TWI), Slope length (LS), Lithology, Soil type, Normalize Different Vegetation Index (NDVI), Rainfall, Aspect, Slope, Plan Curvature (PLC), Profile Curvature (PRC), Lineament density, Distance to faults, and Drainage density. The groundwater quality of the area was predicted by building a Random Forest model based on computed Arithmetic Water Quality Indices (WQI) (as dependent variable) of existing boreholes, to serve as an indicator of the groundwater quality. The predicted WQI of groundwater in the study area shows that it ranges from 9.51 to 69.99%. This implied that 21.97 %, 74.40 %, and 3.63 % of the study area had respectively the likelihood of excellent. The models were found to perform much better with an RMSE of 23.03 and an R2 value of 0.82. The study conducted highlighted an essential understanding of the groundwater quality in the study area, paving the way for further studies and policy development for groundwater management.

An analysis of the foremost issues with artisanal and small-scale gold mining from Ghana's perspective

Ghana has abundant mineral reserves in many of its regions, and gold mining remains one of the country's main sources of revenue. Given Ghana's current position in the global gold market, this review provides insight into the ASGM sector to give an understanding of the pertinent issues in the sector and its role in the socio-economic development of the country. This review assesses the effects of ASGM operations in economic, social, health, and environmental contexts to raise awareness of issues related to ASGM. It evaluates the measures taken to lessen the consequences of ASGM and maintain the sector's long-term viability. This review considers the foremost issues, including continued Hg use in ASGM, recent use of cyanide in ASGM, pollution of water bodies, and toxic metal contamination. It takes into account sustainable measures and remedial techniques that Ghana has implemented to alleviate the negative effects and support best mining practices. The primary factors influencing people to participate in ASGM are the need for quick sources of income, the scarcity of jobs in rural areas, the economic hardship, the need to supplement earnings from other activities like trading, and the comparatively meager profits from agricultural activities. Findings indicated that to gain more traction in addressing the challenges in the ASGM sector, the involvement of the community and direct stakeholders is essential to promoting responsible mining and environmentally sustainable practices. This review will increase awareness and pressure on decision-makers, researchers, and ASGM communities about the relevance of environmental conservation and sustainability.

Perceptions and realities of mercury contamination in a Peruvian artisanal and small-scale gold mining (ASGM) community

Artisanal and small-scale gold mining (ASGM) is the leading global source of mercury pollution. Efforts to reduce or eliminate mercury use in ASGM have produced limited results, in part because they do not engage the complex socio-technical nature of mercury issues in ASGM. The paper takes a multidisciplinary approach to understand the mercury issue with a socio-technical lens, pairing sampling of mercury in soils with surveys of miners' and residents' perceptions of mercury pollution and its dispersion. The research was conducted in Secocha, an ASGM boomtown in southern Peru. Mercury levels in soils exceeded relevant standards in both industrial zones (average of 72.6 mg/kg, versus the Peruvian standard of 24 mg/kg) and residential/urban zones (average of 9.5 mg/kg, versus the Peruvian standard of 6.6 mg/kg). Mercury levels were highest where processing and gold buying activity were concentrated. Surveys revealed that miners and residents correctly assumed mercury pollution to be highest in those areas. However, respondents seemed to underestimate the extent of mercury pollution in other parts of town, and many believed that only those who handle mercury directly were affected by it. Respondents also placed low priority on reducing mercury pollution. Miners' and residents' partial knowledge about mercury contamination and the low priority accorded to the issue suggest that mercury reduction efforts would likely be met with indifference and potentially resistance.

Impact of Small-Scale Mining Activities on Physicochemical Properties of Soils in Dunkwa East Municipality of Ghana

The quality of soils in rehabilitated small-scale mined sites needs thorough investigation since a lot of changes do occur. The study assessed the impacts of small-scale mining activities on concentration and distribution of soil physicochemical properties and heavy metals. The soil samples were collected from 120 (50 m × 50 m) plots. The concentrations of soil physicochemical properties (Ca, Mg, Na, N, P, K, and OC and EC) varied significantly (p < 0.05) between unmined and mined soils. However, there were no statistically, significant differences (p < 0.05) observed in the concentrations of Cd, Hg, Pb, As, and Cu between the unmined and mined soils. Despite the generally poor (33.8%) soil quality in the study area, mining activities further reduced it by 24.2%. Soils from mined sites with unfilled/partially filled pits had higher levels of K, Mg, and Na. As mined sites fallow period increased, concentrations of OC and Cd increased, while Ca, Mg, pH, Cu, Pb, and As and value of EC decreased. The number of years that mined land remained fallow, and whether the pits were filled or unfilled during this period should be factored into the mined land rehabilitation processes.

Mercury (Hg) use and pollution assessment of ASGM in Ghana: challenges and strategies towards Hg reduction

Reduction or possible elimination of Hg from artisanal and small-scale gold mining (ASGM) is one of the main goals of the Minamata Convention on Mercury, which has been signed by many countries involved in ASGM, including Ghana. This article provides a recent overview of ASGM gold production and Hg use in Ghana. In addition, in order to highlight the impacts of Hg use in Ghana, a review was conducted on research studies investigating Hg pollution in waterbodies, soils, fish, and humans caused by ASGM over the past two decades. The continued use of Hg in Ghana's growing ASGM sector has resulted in reportedly high Hg levels found in water, sediments, crops, and miners, which exceed international guidelines. A subsequent ASGM ban and increased monitoring of illegal mining activities in Ghana have not ultimately been successful at significantly reducing Hg use and its associated impacts caused by rampant use in the country. Moreover, Hg alternatives in the ASGM sector are limited in Ghana, with little funding, support, education, and training in place to promote their implementation. As gold produced by ASGM continues to increase annually, clear policy reforms targeting Hg use are vitally needed, as well as efficient strategies to remediate Hg-contaminated areas.

Use of mercury isotopes to quantify sources of human inorganic mercury exposure and metabolic processes in the human body

The pathways of human mercury (Hg) exposure are complex and accurate understanding of relative contributions from different pathways are crucial for risk assessment and risk control. In this study, we determined total Hg concentration and Hg isotopic composition of human urine, dietary components, and inhaled air in the Wanshan Hg mining area (MA), Guiyang urban area (UA), and Changshun background area (BA) to understand Hg exposure sources and metabolic processes in human body. At the three studied sites, total gaseous mercury (TGM) showed negative δ²⁰²Hg (-3.11‰ to + 1.12‰) and near-zero Δ¹⁹⁹Hg (-0.16‰ to + 0.13‰), which were isotopically distinguishable from Hg isotope values of urine (δ²⁰²Hg: -4.02‰ to - 0.84‰; Δ¹⁹⁹Hg: -0.14‰ to 0.64‰). We observed an offset of -1.01‰ to -1.6‰ in δ²⁰²Hg between TGM and urine samples, and an offset of -1.01‰ to 0.80‰ in δ²⁰²Hg between rice and urine samples, suggesting that lighter isotopes are more easily accumulated in the kidneys and excreted by urine. We proposed that the high positive Δ¹⁹⁹Hg in urine samples of UA was derived from fish consumption. The results of a binary mixing model based on Δ¹⁹⁹Hg were compared with those from a classic dietary model. The results from the MIF binary model showed that fish consumption accounted for 22% of urine Hg in the families at UA, whereas fish consumption contributed limited Hg to MA and BA. This study highlighted that Hg isotopes can be a useful tracer in understanding the sources and fates of Hg in human bodies.

Mercury Exposure in Artisanal and Small-Scale Gold Mining Communities in Sukabumi, Indonesia

BACKGROUND

Artisanal and small-scale gold mining (ASGM) is one of the largest sources of mercury (Hg) pollution in Indonesia. In West Java Province, ASGM is found in Bogor, Cianjur, and Sukabumi Regencies.

OBJECTIVES

The present study aimed to evaluate Hg contamination effects and socioeconomic factors in communities living around ASGM operations in Sukabumi Regency.

METHODS

A quantitative method was used to describe socioeconomic ASGM communities. The concentrations of total mercury (T-Hg) in hair were measured in 71 respondents. This study also assessed perception of the use of Hg in the gold ore processing and their impact on the environment.

RESULTS

The population of gold miners in the studied three villages was 1300 households (25.77% from a total of 5044 households). Artisanal and small-scale gold mining involves both men and women employed as miners and gold amalgam processors, respectively. The average monthly income generated as much as Indonesian Rupiah (IDR) 272 000-2 000 000 (about 19-140 USD). Total Hg analysis was conducted for hair samples of 71 respondents (38 men, 33 women). The results showed an average T-Hg in men of 3.27±2.89 ppm, and women of 5.91±4.69 ppm. The level of T-Hg in the respondents was associated with distance to the ball mills and not related to distance to the mine site.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

This study was approved by Ministry of Environment and Forestry of the Republic of Indonesia.

COMPETING INTERESTS

The authors declare no competing financial interests.

Artisanal and small-scale gold mining: A cross-sectional assessment of occupational mercury exposure and exposure risk factors in Kadoma and Shurugwi, Zimbabwe

In artisanal and small-scale gold mining (ASGM) the toxic metal mercury is used for gold extraction. The objective of this cross-sectional study was to assess mercury concentrations in urine and blood and mercury-related symptoms of participants identifying themselves as miners from Kadoma and Shurugwi, Zimbabwe. Moreover, we aimed to explore possible risk factors influencing mercury body burden. In 2019, urine and blood samples of 207 participants were collected and analyzed for mercury using atomic absorption spectroscopy. All participants answered questions regarding their exposure risks. The median urine mercury value was 4.75 μg/L with a maximum of 612 μg/L. Median mercury concentration in creatinine corrected urine values was 3.98 μg/g with a maximum value of 478 μg/g. The median blood mercury value was 2.70 μg/L with a maximum of 167 μg/L. Correlations between exposure risks factors such as the lack of retort use and elevated mercury values were demonstrated. ASGM is very common in Zimbabwe. Thus, mercury exposure is a major occupational health risk for miners. Moreover, this study emphasizes the impact of exposure risk factors on the mercury body burden.

Distribution characteristics and influencing factors of heavy metals in scalp hair of Huainan urban residents

In order to explore the level of heavy metal pollution in human hair of residents in Huainan City and provide theoretical guidance for prevention and control of heavy metal pollution, human hair samples from 174 residents in Huainan City were collected so that heavy metal (Cr, Cu, Pb, Zn, As, and Fe) concentrations in scalp hair could be tested, and meanwhile their relationship with sex, age, and spatial distribution characteristics could be explored as well. According to the final analysis, the average concentration of Cr, Pb, Cu, Fe, Zn, and As in human hair amounted to 1.56, 6.41, 14.96, 31.13, 166.54, and 1.07 mg/kg. The highest average of Cr and Pb contents in human hair occurred in the area of Xiejiaji District; Fe, Zn, and Hg were in Datong District; and Cu and As were in Panji District respectively. Overall, the lowest risk of heavy metal exposure existed in Tianjia'an District. Heavy metal content in hair varied across sexes and ages. Pb concentration in hair would decrease as age increased. The highest Pb concentration appeared in children between ages 0 and 10, the amount of which was significantly different from that in other age groups; hence, children appear to be more susceptible to Pb pollution than other ages. Contents of Cr, Fe, Zn, and As in hair would also increase with age; Fe content in hair was particularly correlated with age. The contents of Cr, Pb, Fe, and As in men's hair were higher than those in women's, whereas the case of Cu and Zn was just the opposite. There were significant differences between sexes concerning the contents of Cr, Cu, and As, and a highly significant difference about Zn between sexes as well. These results indicated that the contents of heavy metal in residents' hair would be closely related to the features of the local environment and population.