Heavy Metal Exposure as a Risk Factor for Gastrointestinal Cancers

Abstract

Background: Gastrointestinal (GI) cancers represent a significant global health burden, with environmental factors such as heavy metal exposure increasingly recognized as potential contributors. This study aimed to investigate the association between heavy metal concentrations—specifically arsenic, cadmium, lead, mercury, and chromium— and the risk of GI cancers in a population from a low-income setting. Methods: A cross sectional observational study was conducted involving 200 participants, including 100 GI cancer patients and 100 matched controls. Heavy metal levels were measured in blood, urine, and hair samples using atomic absorption spectroscopy. Logistic regression analysis was performed to evaluate the relationship between heavy metal exposure and GI cancer risk, adjusting for confounders. Results: Significantly elevated levels of arsenic and cadmium were observed in cancer patients compared to controls (p < 0.001). Both metals were independently associated with increased GI cancer risk, with adjusted odds ratios of 3.45 (95% CI: 2.10–5.67) for arsenic and 2.87 (95% CI: 1.65–4.99) for cadmium. Elevated lead levels also showed a moderate association, while mercury and chromium were not significantly linked. Combined high exposure to arsenic and cadmium posed the greatest risk. Conclusion: Elevated exposure to arsenic and cadmium is strongly associated with gastrointestinal cancers, highlighting the urgent need for environmental monitoring and interventions to reduce heavy metal contamination in vulnerable populations. Further studies are warranted to elucidate underlying mechanisms and inform prevention strategies.