Smoking tobacco over a period of 20 years results in the absorption of a measurable amount of polonium-210 radiation, primarily through inhalation. Polonium-210 is a highly radioactive alpha-emitting isotope that accumulates in tobacco leaves from environmental contamination and the decay chains of uranium and radium present in soil and fertilizers. When smoked, polonium-210 particles are inhaled deep into the lungs, where their alpha radiation can cause significant cellular damage.
Polonium-210 emits alpha particles, which are helium nuclei with high energy but very low penetration power; they cannot penetrate skin but are extremely harmful when deposited inside lung tissue. The half-life of polonium-210 is about 138 days, meaning it decays relatively quickly but continuously replenishes as smokers inhale new doses with each cigarette.
The amount of polonium-210 absorbed depends on several factors: the number of cigarettes smoked daily, the concentration of polonium in those cigarettes (which varies by brand and growing conditions), and individual smoking habits such as depth and frequency of inhalation. On average, cigarette smoke contains roughly 0.03 to 0.1 picocuries (pCi) or about a few becquerels per cigarette due to polonium-210 content.
Over 20 years—assuming an average smoker consumes one pack per day (about 20 cigarettes)—the cumulative intake can be estimated by multiplying daily intake by total smoking days (approximately 7,300 days). This results in an internal deposition measured in tens to hundreds of becquerels cumulatively absorbed into lung tissue over time.
Because alpha particles cause dense ionization tracks within very short ranges inside cells lining the respiratory tract, even small amounts lead to DNA damage that increases cancer risk significantly. Studies have shown that this internal exposure contributes notably to lung cancer incidence among smokers beyond other carcinogens present in tobacco smoke.
In terms of radiation dose absorbed by lung tissues from polonium-210 alone during two decades:
– The committed effective dose from inhaled polonium can reach several hundred millisieverts (mSv), depending on exposure levels.
– This dose is concentrated locally within bronchial epithelium cells where deposition occurs.
This localized high-dose alpha irradiation causes mutations leading to malignant transformations over long periods.
To put it simply: while external radiation exposure at these levels would be considered moderate or low risk for cancer induction if spread uniformly across the body surface area or organs, internally deposited alpha emitters like polonium deliver intense doses directly at sensitive sites inside lungs—making them far more biologically damaging per unit activity than gamma or beta emitters externally applied.
The presence and accumulation rate also depend on how well an individual’s body clears radioactive particles; some fraction remains lodged for months before decaying fully due to its half-life characteristics combined with biological retention timescales.
In summary:
Smoking for twenty years leads to continuous ingestion/inhalation and retention within lungs of measurable quantities—on order tens-to-hundreds becquerels cumulatively—of highly radiotoxic polonium-210 whose emitted alpha particles cause severe localized cellular damage increasing lung cancer risk substantially compared with non-smokers who do not have this internal source concentrated directly inside their respiratory system.
