Tobacco is a source of mineral elements that can affect human health in various ways, such as lithium, which is used as a psychiatric medication. Lithium salts are used as mood-stabilizing drugs and indicated in the treatment of manic-depressive psychosis.

Studying the lithium content in tobacco over the smokers’plasma content and evaluate the potential role of lithium in tobacco addiction.

A total of 18 different tobacco products (cigarettes, smokeless and water pipe tobacco) and 125 plasma samples (45 from smokers, 10 from ex-smokers and 70 from non-smokers) were collected to determinate the lithium content. Tobacco samples were digested with nitric acid and lithium concentration was measured by inductively coupled plasma-optical emission. The collected plasma samples were diluted 1/10 with a nitric acid solution and the lithium level was measured by inductively coupled plasma-mass spectrometry.

The average concentration of lithium in the cigarettes (16.59 ± 0.59 μg/g) was higher compared to those in the smokeless tobacco (8.39 ± 4.44 μg/g) and in the water pipe tobacco (6.13 ± 6.32 μg/g) but with no significant difference (P = 0.182). For plasma lithium levels, there was no significant difference (P = 0.186) between smokers and non-smokers (6.20 ± 6.24 vs. 4.98 ± 6.20 μg/g). However, a significant negative correlation was noted between plasma and the lithium content in tobacco products (r = –0.435; P = 0.04). The lithium plasma level was significantly and negatively correlated with the dependence score (r = –0.316; P = 0.031).

The correlation between plasmatic lithium and dependence score in smokers suggests that lithium would be involved in tobacco addiction probably through his regulating action of mood.

The authors have not supplied their declaration of competing interest.