Review of natural radioactivity in tobacco cigarette brands

Cigarettes smoking are leading causes of lung cancer in the world. In several countries, the radioactivity of tobaccos cigarette brands has been evaluated to estimate the effective dose from smoking inhalation. In this paper, we have reviewed 40 researched papers of radioactivity in tobacco cigarette brands by searching specified databases from various search engines such as Web of Science, Google Scholar, Scopus, Science Direct and PubMed for the studies published between the year 2000 and November, 2023 in English language. Results show that, the arithmetic mean and range of radioactivity concentration in mBq/g were 20.4 (0.4-128.6), 15.4 (2.0-78.8), 630.8 (1.2-1330.0), 8.1 (0.3-41.0), 15.2 (0.2-82.0) and 5.9 (2.0-16.0) from ²¹⁰Po, ²¹⁰Pb, ⁴⁰K, ²³²Th and ²³²U and ²²⁶Ra, respectively. The annual effective doses were also estimated using the assumption that a smoker smokes 20 cigarettes per day. The mean annual effective doses in μSv/y from ²¹⁰Po, ²¹⁰Pb, ⁴⁰K, ²³²Th and ²³²U and ²²⁶Ra were 295, 74.1, 5.80, 889.7, 192.6 and 90.1, respectively. The mean annual effective dose is lower than the reference level 1000 to 20000 μSv/y for existing situation in ICRP Publication 103. The average value of ELCR is 1.03 ×10^-3, 0.26 ×10^-3,0.02 ×10^-3,3.11 ×10^-3,0.67 ×10^-3 and 0.32 ×10^-3 for ²¹⁰Po, ²¹⁰Pb, ⁴⁰K, ²³²Th and ²³²U and ²²⁶Ra, respectively. The ELCR values obtained in this study are well below the world average value of 1.45 ×10^-3. The mean value of LCC in per million is 5.3, 1.3, 0.1, 16, 3.5 and 1.6 for ²¹⁰Po, ²¹⁰Pb, ⁴⁰K, ²³²Th and ²³²U and ²²⁶Ra, respectively. The values of LCC obtained in this study are all below the limit range of 170-230 per million persons. The result shows ²³²Th contribute much larger for annual effective dose, annual equivalent dose, ELCR and LCC for smoking tobacco cigarette brands compared to other radionuclides. More studies in radioactivity in tobacco cigarette brands from different countries are required to have conclusive mean annual effective dose, annual equivalent dose, ELCR and LCC for each natural radionuclide.