Exposure to toxic chemical elements among people living with HIV/AIDS in Northern Tanzania

Environmental exposure to toxic chemicals including cadmium (Cd), lead (Pb), and mercury (Hg), are known risk factors for cardiovascular (CVD) and kidney disease. In people living with HIV (PLWH), CVD and kidney disease are the leading cause of death. Neither traditional risk factors nor markers of HIV infection fully explain such an increased risk. It is of paramount importance to establish the epidemiology of toxic chemicals exposure in PLWH, to inform screening and prevention interventions in this vulnerable population. This cross-sectional study compares toxic chemical levels (T-Cd, T-Pb, and T-Hg) among PLWH and HIV-uninfected adults in Northwestern Tanzania. A total of 495 PLWH and 505 HIV-uninfected subjects were analyzed. Spearman's rank correlations were used to examine the relationship between toxic chemical elements by HIV status. Linear regression models were used to determine the association between exposures and outcomes of interest among study participants. In both PLWH and HIV-uninfected adults, blood T-Cd, T-Pb, and T-Hg levels were frequently found at levels above the reference value of 5, 50, and 20 μg/L, respectively. Overall, factors associated with blood toxic chemical levels included vegetable servings per week, obesity, untreated water sources, use of alcohol, and HIV. Among PLWH, weekly vegetable intake provided a protective effect against T-Cd (Coeff = −0.03, 95%CI = −0.06, −0.01) and T-Pb (Coeff = −0.05, 95%CI = −0.09, −0.01) exposure among PLWH. Alcohol intake (Coeff = 0.10, 95%CI = 0.06, 0.13), obesity (Coeff = 0.08, 95%CI = 0.02, 0.13), longer duration to indoor smoke exposure (Coeff = 0.003, 95%CI = 0.001, 0.004), and HIV infection (Coeff = 0.11, 95%CI = 0.07, 0.15) were associated with increased individuals blood T-Hg levels. Individuals in northwestern Tanzania, including PLWH, have high blood levels for T-Cd, T-Pb, and T-Hg. Factors associated with higher blood levels include water sources, obesity, use of alcohol, exposure to indoor smoke, and HIV infection. •Two-thirds of Tanzanians had elevated blood levels of lead, cadmium, or mercury.•Elevated lead was highly prevalent and often overlapped with elevated cadmium.•Elevated mercury was more common in people with HIV, even after adjustment.•Metal levels also linked to untreated water, alcohol, and indoor smoke exposure.•Lead and cadmium levels were strongly correlated, suggesting a common source.