Exposure to Heavy Metals Arsenic, Cadmium and Lead Exacerbates Carcinogenic and Noncarcinogenic Health Risks Among...

Exposure to toxic metals contributes to the growing burden of noncommunicable diseases (NCDs), yet evidence from sub-Saharan Africa remains limited. This hospital-based cross-sectional study assessed heavy metal (arsenic [As], cadmium [Cd], lead [Pb]) exposure levels and their association with health risks in adult diabetic and hypertensive patients in Cameroon. It involved 178 participants (39 diabetics, 78 hypertensives, 61 comorbid), and the urinary metals were quantified using atomic absorption spectrophotometry and normalized to creatinine. Serum oxidative stress biomarkers including glutathione (GSH), thiobarbituric acid reactive substances (TBARS) and paraoxonase 1 (PON1) were measured. Health risk indices including estimated daily intake (EDI), chronic daily intake (CDI), hazard quotient (HQ), hazard index (HI) and cancer risk (CR), were computed. Proportion contribution trend (PCT), receiver operating characteristic (ROC) and ordinary least squares (OLS) regression were applied for risk and predictive analyses. Diabetic patients exhibited significantly higher (p < 0.05) urinary Cd (5.21 ± 0.83 μg/g creatinine) and Pb (0.66 ± 0.12 μg/g creatinine) levels compared with hypertensive and comorbid patients. GSH levels were markedly lower (p < 0.05) in diabetics than in hypertensives. Although HQs and HIs were < 1, diabetics recorded the highest HI (2.73 × 10^-1 ± 2.27 × 10^-2; p < 0.05), indicating increased chronic exposure risk. CR values for As and Cd exceeded USEPA thresholds (10^-6), with diabetics showing the greatest risk. PCT identified Cd as the dominant contributor to HI across groups. ROC analysis showed that As CDI moderately predicted CR in diabetics (AUC = 0.604; p = 0.047). OLS regression revealed water source and residence as significant determinants of As and Pb exposure. Summarily, diabetic individuals demonstrated disproportionately higher heavy metal exposure and associated carcinogenic risk, largely driven by Cd. Integrating environmental biomonitoring into NCD management is essential to mitigate heavy metal-related health burdens in Cameroon.