Genetic Damage and Multi-Elemental Exposure in Populations in Proximity to Artisanal and Small-Scale Gold (ASGM) Mining Areas in North Colombia

Abstract

This study evaluates DNA damage and multi-element exposure in populations from La Mojana, a region of North Colombia heavily impacted by artisanal and small-scale gold mining (ASGM). DNA damage markers from the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay, including micronucleated binucleated cells (MNBN), nuclear buds (NBUDs) and nucleoplasmic bridges (NPB), were assessed in 71 exposed individuals and 37 unexposed participants. Exposed individuals had significantly higher MNBN frequencies (PR = 1.26, 95% CI: 1.02-1.57, p = 0.039). Principal Component Analysis (PCA) identified the "Soil-Derived Mining-Associated Elements" (PC1), including V, Fe, Al, Co, Ba, Se and Mn, as being strongly associated with high MNBN frequencies in the exposed population (PR = 10.45, 95% CI: 9.75-12.18, p < 0.001). GAMLSS modeling revealed non-linear effects of PC1, with greater increases in MNBN at higher concentrations, especially in exposed individuals. These results highlight the dual role of essential and toxic elements, with low concentrations being potentially protective but higher concentrations increasing genotoxicity. Women consistently exhibited higher MNBN frequencies than men, suggesting sex-specific susceptibilities. This study highlights the compounded risks of chronic metal exposure in mining-impacted regions and underscores the urgent need for targeted interventions to mitigate genotoxic risks in vulnerable populations.

Keywords: GAMLSS; La Mojana; artisanal and small-scale gold mining (ASGM); cytokinesis-block micronucleus cytome assay (CBMN-Cyt); gold mining; multi-elemental exposure.

Figure 1

Study area in the La Mojana swamp complex in Colombia, highlighting the municipalities of Ayapel (Córdoba), Magangué (Sucre) and Caimito (Sucre), along with the main tributaries of the swamp complex. The circled area provides a centered and zoomed-in view of the study location within northern Colombia.

Figure 2

Comparison of log-scaled essential and toxic element concentrations in hair samples from exposed and unexposed populations. (A) Essential elements and (B) toxic elements are shown as boxplots, where boxes represent interquartile range (IQR), horizontal lines indicate median values and whiskers represent minimum and maximum observed concentrations. Comparisons between exposed and unexposed groups are illustrated, with statistical significance denoted as follows: p < 0.05 (*) and p < 0.01 (**).

Figure 3

Loadings of chemical elements in the first four principal components. The plots display the contributions (loadings) of each element to the first four principal components (PC1–PC4). Positive loadings (red) indicate elements that are strongly associated with a given component, while negative loadings (blue) reflect opposing contributions.

Figure 4

Non-linear effects of principal components on MNBNs, differentiated by sex, according to GAMLSS model. Panel (A) represents reference group, while panel (B) illustrates exposed population.

Figure 4

Non-linear effects of principal components on MNBNs, differentiated by sex, according to GAMLSS model. Panel (A) represents reference group, while panel (B) illustrates exposed population.