Estimation of Nickel in Different Smokeless Tobacco Products and Their Impact on Human Health of Oral Cancer Patients

It has been extensively investigated that the chewing of smokeless tobacco (SLT) products may enhance the inflammation of the oral cavity. The aim of the present study is to evaluate the relationship between nickel (Ni) exposure via different SLT products with oral cancer (different sites) incidence in the population of Sindh, Pakistan. The different brands of SLT products (mainpuri, gutkha, and moist snuff) commonly consumed by the studied population were analyzed for Ni contents. The biological samples of oral cancer patients and noncancerous control subjects of both genders, who have or have not consumed SLT products, were collected. The concentration of Ni in biological samples and SLT products were measured by electrothermal atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by using certified reference materials. The results of this study showed that the Ni level was significantly higher in scalp hair and blood samples of oral cancer patients compared to controls (P < 0.01). The study suggested that exposure of Ni as a result of chewing different SLT products may be synergistic with risk factors associated with oral cancer.