Smoking one pack of cigarettes per day results in the inhalation of approximately 0.03 to 0.1 picocuries (pCi) of polonium-210, which corresponds to a few picograms of this radioactive element. This amount, although extremely small in mass, is significant because polonium-210 emits alpha particles that cause intense localized radiation damage in lung tissue.
Polonium-210 is a naturally occurring radioactive isotope found in tobacco leaves primarily due to contamination from lead-210, which settles on the leaves from the atmosphere. This lead-210 originates from radon gas decay, which itself comes from radium-226 present in phosphate fertilizers used in tobacco farming. When tobacco is smoked, polonium-210 is released in the smoke and inhaled directly into the lungs.
The quantity of polonium-210 inhaled from smoking depends on several factors including the number of cigarettes smoked, the tobacco source, and the smoking behavior. On average, a single cigarette delivers about 0.003 to 0.01 picocuries of polonium-210 to the smoker’s lungs. Therefore, smoking a pack of 20 cigarettes daily results in inhaling roughly 0.06 to 0.2 picocuries per day. In terms of mass, this translates to a few picograms (trillionths of a gram), but the radioactive decay and alpha particle emission make even this tiny amount hazardous.
The danger of polonium-210 lies in its alpha radiation, which cannot penetrate the skin but is highly damaging when emitted inside the body. Alpha particles cause severe ionization and DNA damage in lung cells, contributing to mutations and increasing the risk of lung cancer. Polonium-210’s half-life of about 138 days means it remains radioactive long enough to cause significant biological damage after inhalation.
Despite decades of research, tobacco companies have been unable to effectively remove polonium-210 from cigarettes. The isotope’s presence is a persistent contributor to the carcinogenicity of tobacco smoke, alongside other harmful chemicals like benzene, formaldehyde, and nitrosamines.
Inhaling polonium-210 from smoking is particularly insidious because it is not easily detected by standard radiation detectors due to its low-energy gamma emissions. This makes it a hidden but potent source of radiation exposure for smokers.
The cumulative effect of inhaling polonium-210 over years of smoking significantly increases the risk of lung cancer. Each cigarette contributes to DNA damage, and the alpha radiation from polonium-210 intensifies this damage in lung tissue. Over time, the accumulation of such damage overwhelms the body’s repair mechanisms, leading to malignant transformations in lung cells.
In summary, smoking a pack of cigarettes daily exposes the lungs to a small but biologically significant amount of polonium-210. This radioactive element, delivered deep into the lungs via tobacco smoke, emits alpha particles that cause severe cellular damage and contribute to the high incidence of lung cancer among smokers.
