As demand for critical minerals accelerates, mining risks reinforcing existing inequalities in communities near extraction sites. Our research shows that unequal impacts are shaped not only by mining activities themselves, but by pre-existing social, economic and health vulnerabilities. Understanding these mechanisms or factors can help governments and companies anticipate harm, strengthen protections and ensure a more equitable energy transition.

In many regions, particularly in the Global South, mining is being driven by global demand for minerals critical to the energy transition and increasing energy needs. Indigenous and other marginalized communities often bear a range of negative impacts from mining such as loss of agricultural land, pollution-related health burdens, and social unrest, while receiving limited benefits in employment and revenues. But why do mining activities affect some populations more severely than others?

This systematic review examined how mining activities affect populations who already experience marginalization. The review catalogued populations in the literature who are marginalized based on their gender, ethnicity (including Indigeneity), age, occupation, geographic location, place of origin, education level, or economic, social, health, employment, or migrant status. The review also covered outcomes across economic, health, wellbeing, social, cultural, human rights, justice and gender dimensions.

A large portion of the studies reviewed focused on health impacts affecting women and children. The qualitative synthesis examined how pre-existing marginalization shaped outcomes for these groups. In a subset of 11 studies, coded mining outcomes were almost exclusively negative (96%) for children, indicating a worsening of marginalization, whereas women experienced both negative (70%) and some positive (30%) outcomes.

Across different minerals, geographies, and mining activities, the synthesis shows that a small set of factors consistently shape differential health and well-being outcomes for women and children. They include biological susceptibility to contaminants, limited access to resources and unequal power. These factors align with environmental justice theory – which describes the systemic sources of unequal environmental impacts on communities – and highlight structural patterns of vulnerability embedded within systems of natural resource extraction.

Findings across mining activities offer important lessons for the ongoing expansion of critical mineral extraction. While more research is needed to better understand the specific contexts of emerging critical mineral supply chains, such as lithium, cobalt, and rare earth metals, waiting until evidence on each specific mineral becomes available risks repeating historical patterns of harm. A process-based understanding of historical mining impacts can support anticipatory, protective governance by identifying pathways through which new mining developments may reinforce or mitigate existing marginalization.

Identifying these cross-cutting factors provides a framework for anticipating unequal outcomes and designing more equitable responses to mining-related risks. Policy and planning efforts should seek not only to mitigate observed impacts but also to address the underlying conditions that shape vulnerability and opportunity. Key entry points include securing land and resource rights for historically marginalized populations and closing gender- and age-based access gaps; improving health protections through enforceable environmental and occupational standards; addressing power inequities through inclusive decision-making, benefit-sharing, and transparent grievance mechanisms; and creating equitable livelihood opportunities.

The literature reviewed also reflects broader limitations in how marginalization is studied in mining research. Many studies do not explicitly identify marginalized populations, highlighting gaps in how vulnerability and differential impacts are measured. Gender- and age-related marginalization, particularly in relation to physical health outcomes, represented the strongest evidence cluster. However, other, more fluid or context-specific dimensions of marginalization, including ethnicity, Indigeneity, disability, migrant status and labor status remain less thoroughly examined.

Future research should bridge the current divide between quantitative and qualitative approaches. While social science studies tend to recognize marginalization, they often fail to explicitly measure exposure and outcomes. On the other hand, quantitative studies tend to focus on easily identifiable population subgroups while leaving many marginalized groups understudied and rarely account for how pre-existing marginalization shapes differential outcomes.

As critical mineral extraction expands, the challenge is not simply to document new harms, but to use existing evidence to anticipate and prevent mining from reinforcing existing inequality.