# Metal uptake in sweet peppers cultivated in soils contaminated by artisanal gold mining: implications for food safety

## TL;DR

This study examines how sweet peppers absorb harmful metals from gold mining-contaminated soils in Colombia and assesses the health risks of consuming them.

## Contribution

The study provides new insights into metal uptake by sweet peppers and evaluates health risks in mining-affected agricultural areas.

## Key findings

- Metal concentrations in soil decreased with distance from mining sites, with the highest levels closest to the mines.
- Sweet peppers showed limited metal uptake and translocation, with most metals accumulating in roots rather than edible parts.
- Health risk assessments indicated low non-carcinogenic and negligible carcinogenic risks for consumers at distances of 3 and 20 km.

## Abstract

Soil contamination by metals poses a significant threat to food safety and human health, particularly through the consumption of vegetables cultivated in mining-impacted areas. In Colombia, gold mining and horticultural activities frequently coexist; however, information on the uptake of mining-associated metals by edible crops and the resulting health risks remains limited. This study investigated the accumulation of mercury (Hg), lead (Pb), and arsenic (As) in sweet pepper (Capsicum annuum) cultivated in soils affected by gold mining and evaluated the potential human health risks. A single-factor experimental design was employed using soils collected at three distances from active mining sites (S1: 0.6 km, S2: 3 km, and S3: 20 km). Plants were grown under screen-house conditions for 143 days, during which morphometric, physiological, and chemical analyses were performed. Soil concentrations of metals decreased with increasing distance from mining activity: S1 (Hg: 22.13, Pb: 1997.02, As: 37.52 mg kg−1), S2 (Hg: 5.38, Pb: 186.03, As: 15.70 mg kg−1), and S3 (Hg: 2.05, Pb: 57.19, As: 7.90 mg kg−1), with generally low bioavailability (Hg and As < 1%; Pb: 2–11%). Metal accumulation occurred predominantly in roots, with limited translocation to aerial and edible tissues. Bioconcentration factor (BCF) and translocation factor (TF) were consistently below unity, indicating limited uptake and internal transfer of Hg, Pb, and As. Human health risk assessment based on Codex Alimentarius provisional tolerable weekly intake (PTWI), margin of exposure (MOE), total hazard quotient (THQ), and incremental lifetime cancer risk (ILCR) indicated low non-carcinogenic risk and negligible carcinogenic risk at distances of 3 and 20 km. Although Hg concentrations exceeded the limits established by the Chinese National Food Safety Standard (GB 2762-2022), which sets a threshold of 0.1 mg kg−1, the overall results suggest no immediate health risk from consumption. Nevertheless, considering the persistence and bioaccumulative nature of these elements, long-term exposure risks cannot be excluded, highlighting the need for continuous monitoring of agricultural systems in mining-influenced regions.

The online version contains supplementary material available at 10.1007/s10653-026-03077-z.