Introduction
The demand for large-scale extraction of mineral and metal resources in Africa continues to rise, driven in part by the global shift towards a low-carbon future [
1]. According to the report of the United Nations Environment Programme (UNEP) [
2], Africa holds a significant share of the world’s mineral reserves, approximately 30% located on the continent. Additionally, Africa holds around 8% of the world’s natural gas reserves and 12% of oil reserves, making it a crucial player in meeting the rising global demand for minerals, metals, oil, and natural gas. Currently, Africa hosts over 2000 industrial mining projects and many more planned.
1 The continent’s rich resources present both opportunities and challenges.
Studies have offered insight into the economic consequences of mining [
4]. Using night light as a measure of economic development, Mamo et al. [
5] found that mining districts benefit from higher living standards relative to other districts in Africa. That is, through job opportunities (particularly in non-agriculture sectors; [
6]) and investments in community development, mining may significantly contribute to poverty reduction and raising living standards. Kotsadam and Tolonen [
7] documented that mining has the potential to enhance non-agricultural sectors, and provide cash-earning opportunities - including women of reproductive age [
8]. Moreover, it has been shown that mineral wealth can spur infrastructure development, including the building of schools, hospitals, and road networks, as well as improve housing conditions, including proper sanitation and safe water [
9,
10]. These improved conditions in turn reduce the incidence of environmental-related diseases such as respiratory infections [
11], diarrhoea diseases [
12], malaria, and undernutrition [
8].
Although the aforementioned studies clearly outline the beneficial effects of mineral wealth and mining activities on economic and health outcomes, several other studies have reported adverse effects on health outcomes [
13]. Direct environmental health effects are extensively researched at the community level. For instance, a study of Goan communities in India found that the production of iron ore had a detrimental influence on health outcomes due to fugitive dust emissions and consequent poor air quality [
14]. It is recognized that mineral-rich communities can be impacted by a wide range of factors, such as transient populations, economic instability, or land degradation caused by the influx of mining activities [
14‐
16]. Consequently, resulting in food insecurity [
17], increased competition on water infrastructure [
18], stunting growth in children [
19], and other health-related outcomes [
20]. The broad strand of literature assessing the impact of mineral wealth on health outcomes is mixed. Studies either identify positive, negative, or mixed effects of mining on a stretch of health outcomes in resource-rich regions [
16,
17,
19]. It has been reported that mineral mining activities in developing countries had mixed effects on local communities; that is, there is a trade-off between wealth gain and health cost [
21]. On one hand, they found that the presence of mines led to economic spillover effects, such as job creation and increased wages, which contributed to improved living standards for some households. On the other hand, their study noted that mineral mining led to a decline in local good health outcomes, particularly in terms of child mortality rates.
Our study aimed to understand the impact of mineral wealth on health outcomes by exploring the potential mechanisms that contribute to the observed negative effects on health. We argued that the observed adverse effect of mineral wealth on health [
13,
21] can largely be attributed to two main factors; namely, ambient air quality and infrastructure strain.
First, the prevalence of artisanal mining has been shown to be high in mineral-rich areas [
22], which is often accompanied by detrimental effects such as environmental degradation, hazardous working conditions, inadequate health and safety precautions, the involvement of child labor, and engagement in illegal mining operations. A growing body of studies suggests that mining sectors are connected to emissions of nitrogen oxide (NOx), sulfur oxide (SOx), and particulate matter (PM10 and PM2.5) from various activities of mine and greenhouse gas emission [
23‐
25]. Leili and colleagues argued that these airborne particles are adversely affecting health by contributing to illness [
26]: for instance, damaging the lungs, damaging the respiratory tract, and causing skin diseases by seeping into the skin both at the sites and in close residential areas. Also, climate change brought on by carbon emissions poses unprecedented challenges to global society in the form of extreme weather, sea level rise, infectious diseases, biodiversity loss, and food shortages [
27]. Thereby contributing to negative health outcomes such as stunting and diarrheal diseases [
19].
Second, natural resource extraction has been linked to urbanizing population agglomerations (mineralized urbanization)
2 due to migration, shifting sectoral job patterns, improved housing, and higher domestic investment [
18,
29]. Prior studies demonstrate that societies in Africa (such as West African countries) fought over territories that had rich-minerals even before the arrival of the European as these resources signified embodiment of power and wealth [
30,
31]. The the arrival of the European and the development of mining industry led to a windfall in infrastructural development in these areas [
32], ultimately increasing population density. However, it has been reported that the high influx of job seekers to remote and rural mining areas can exacerbate the pressure on available water resources and infrastructures [
33]. Additionally, through geospatial visualization, Leuenberger et al. [
18] highlights the spatial distribution of water sources, infrastructure, and health facilities in relation to the mining areas. They identified potential hotspots of water scarcity, contamination, and inadequate sanitation facilities, which can significantly impact the health and well-being of the communities living and working in these mining settings. We argue that the rapid in-migration of individuals to mining areas, driven by the lure of potential economic prosperity, may outpace the rate of local development, thereby wearing down existing public amenities and intensifying competition for their use. This increases the risk of reliance on compromised infrastructure, including water and sanitation facilities, plausibly leading to health risks and negative outcomes. Furthermore, natural resources frequently serve as catalysts for internal conflicts, as various factions vie for dominion over these resources or utilize them to fund their hostile endeavors. A growing body of empirical evidence suggests that rents on primary commodities and natural resources, particularly oil and other point-source resources, increase the likelihood of civil conflicts and wars in Africa by undermining the state or funding rebels, sometimes even by multinational corporations [
34‐
37]. Several studies have reported that governments in many resource-rich countries are unable to safeguard basic security for their citizens since the wealth of resources elicits violence, theft, and looting often financed by rebels and competing warlords [
38,
39]. These events often result in the displacement of lives and properties, straining existing basic infrastructures.
The study’s distinctiveness lies in its investigation of the roots of the observed poor health outcomes in mineral-rich areas, transcending beyond the impact of mining activities. With few exceptions, prior studies have attributed the adverse health outcomes in mineral-rich areas solely to activities by extractive industries. The study further contributes to the limited understanding of the impact of mining activities on ambient air quality in the developing world. It contributes to the literature on the impact of population dynamics on health outcomes by highlighting one of its consequences on available amenities (consequently, increasing the risk of reliance on compromised structures).
This study explored the possible mechanisms that lead to the observed adverse effects of mineral wealth on health outcomes in Africa. The findings could provide new insights for policymakers and various stakeholders to design or adjust schemes related to reducing environmental pollution and health-related risk associated with the extraction of these resources.
Discussion
The study found that the presence of these valuable minerals is associated with a heightened prevalence of environmental risks, potentially providing an explanation for the health costs linked to mineral wealth as documented in Von der Goltz and Barnwal [
21], Stuckler et al. [
51]. The findings of the underlying study provide a comprehensive framework for understanding the multifaceted challenges faced by communities in mineral-rich areas.
The presence of valuable mineral deposits may inadvertently contribute to competition and deterioration in the quality of accessible water sources, thereby exposing local population to various health risks. Reliance on polluted water sources has been increasingly linked to the transmission of diarrhoeal diseases such as cholera, polio, and typhoid [
52,
53]. According to the WHO Diarrhoea Report (2023) [
54], diarrhoeal diseases is regarded as the second most prominent cause of mortality among children below the age of 5. This could perhaps justify the high prevalence of child-related mortality and morbidity in these areas [
55]. The results of the mediation analysis revealed that the heightened dependence on contaminated water sources, as observed, stems from both the influx of individuals into these mineral-rich regions and the occurrence of conflict events. The influx of people to mineral-rich areas may strain the existing clean water infrastructure. With this increased competition, the demand for water may exceed the capacity of available safe water sources, resulting in the use of contaminated or inadequately treated water. Moreover, the findings indicated that violent events are an underlying cause for this observation. As stated earlier, valuable mineral deposits tend to fuel armed fighting [
36]. Previous studies have documented the devastating impact conflict events and military actions have on freshwater resources and water infrastructures [
56,
57]. Interestingly, our findings unveiled a distinct twist: the noticeable prevalence of depending on contaminated water sources in mineral-rich domains was not propelled by the activities of extractive companies (mines). This finding could be largely attributed to our measurement of mining activities. We relied on the Berman and coauthors measure, which incorporates only large-scale mines [
34]. These large-scale extractive organizations often operate under strict regulations and tend to compensate for the environmental repercussions of their actions. Our results corroborate the findings of Dietler et al. [
10], which suggest that mining projects could improve household access to modern water infrastructure.
The study further found a positive association between the presence of mineral deposits and reliance on open defecation and unimproved sanitation. Again, this finding clearly underscores the intricate interplay between economic opportunities arising from mineral deposits and the challenges of maintaining essential sanitation infrastructure and practices. Similar findings have been reported by Padhi et al. [
58], Leuenberger et al. [
59]. Due to the influx of people to these areas, the available sanitation system may be strained, resulting in insufficient access to toilets and waste management services, among other essential hygiene amenities. As a result, the number of people relying on open defecation and inadequate sanitation facilities spikes. Our finding offers an understanding of recent studies that document a negative association between population density and health outcomes [
60]. Furthermore, the findings showed that mining activities contribute to the observed adverse effect of mineral deposits and reliance on open defecation and unimproved sanitation. A plausible justification for this observation can be attributed to the enclave nature of these large-scale extractive industries [
61]. It is entirely possible that these extractive industries can prioritize their operations over local community development, exacerbating the challenges of poor sanitation. Again, the results underscored that natural resources can, often do, incite and prolong internal conflicts as various armed groups contend for control of the resources or utilize the resources to fund their hostilities. The result of these events is the destruction of lives and properties, making it increasingly difficult to access improved sanitation facilities
6. This puts stress on existing if not destroyed sanitation facilities, forcing people to rely on unimproved sanitation facilities and practices.
Regarding the relationship between valuable mineral deposits and ambient air quality, the findings showed that at the 1% level, the presence of mineral deposits is positively related to particulate matter concentration. However, a weak association was observed between mineral resources and atmospheric carbon concentration. The results suggest that regions with abundant valuable minerals tend to experience poor air quality, which can have adverse effects on respiratory health and overall well-being. This result offers a clear understanding of the reported prevalence of respiratory health issues in mineral-rich areas [
62]. Mining activities can contribute to the release of fine particles into the atmosphere. These particles, often originating from processes like excavation, transportation, and mineral processing, can become suspended in the air, leading to elevated particulate matter concentrations. Also, the sudden surge in people and economic activities in these mineral-rich areas can contribute to the observed increase in particulate matter concentration. This finding corroborates with prior studies [
63‐
65]. The study found that the reported higher carbon concentrations in mineral-rich areas are not caused by extractive industry operations. These observations particularly affirm the assertion that the nature of carbon emissions can be influenced by a range of factors beyond just mining activities, including energy sources, transportation, and land use practices. Moreover, several studies such as Yeboah [
66] have demonstrated that large-scale mining enterprises engage in sustainable initiatives, like reforestation, within the regions where their operations are conducted. Convincingly, the robustness analysis shown in Column 5 of Table
10 indicated a diminishing statistical effect of mineral deposits on atmospheric carbon concentration.
The study contributes to a more comprehensive understanding of the environmental challenges posed by mineral wealth, our findings, nevertheless, are not without limitations. First, our analysis relied on cross-sectional study design approach. Although efforts were made to document causal estimates, this approach does not allow us to analyse the relationship over time. Secondly, the measure of activities of extractive companies excludes artisanal mining, hence, our findings should be interpreted in light of large-scale extractive industries. Finally, our documented relationship between mineral deposits and \(CO_2\), our mediators, does not explain much of this relationship. In general, albeit our mediators explain about 49.8% to 77.7% of the documented relationship between mineral wealth and environmental health risks, we fail to document all the putative mechanisms driving these intricate relationships.
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