Background: Cigarette smoking interferes with the metal homeostasis of the human body, which plays a crucial role for maintaining health. A significant flux of heavy metals, among other toxins, reaches the lungs through smoking. In the present study, the relationship between toxic element (TE) exposure via cigarette smoking and hypertension incidence in population living in Dublin, Ireland is investigated.
Methods: The toxic elements arsenic (As), aluminum (Al), nickel (Ni), and lead (Pb) were determined in biological (scalp hair and, blood) samples of patients diagnosed with hypertension who are smokers living in Dublin, Ireland. These results were compared with age- and sex-matched healthy, nonsmoker controls. The different brands of cigarettes (filler tobacco, filter, and ash) consumed by the studied population were also analyzed for As, Al, Ni, and Pb. The concentrations of TEs in biological samples and different components of the cigarettes were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials.
Results: The recovery of all the studied elements was found to be in the range of 97.8% - 99.6% in certified reference materials. The filler tobacco of different branded cigarettes contains As, Al, Ni, and Pb concentrations in the ranges of 0.432 - 0.727 μg, 360 - 496 μg, 0.715 - 1.52 μg, and 0.378 - 1.16 μg/cigarette, respectively. The results of this study showed that the mean values of Al, As, Ni, and Pb were significantly higher in scalp hair and blood samples of hypertensive patients in relation to healthy controls, while the difference was significant in the case of smoker patients (p < 0.001). The levels of TEs were 2 - 3-fold higher in scalp hair and blood samples of non-hypertensive smoker subjects as compared to nonsmoker controls.
Conclusions: The high exposure of toxic metals as a result of cigarette smoking may be synergistic with risk factors associated with hypertension.