The radiation exposure from 5 mammograms is roughly equivalent to the radiation you would receive from smoking about 100 to 200 cigarettes. This comparison helps put the amount of radiation from mammograms into perspective by relating it to a more familiar risk factor like cigarette smoking.
To understand this, it’s important to know that a single mammogram exposes a woman to about 0.4 millisieverts (mSv) of ionizing radiation. Five mammograms would therefore total around 2 mSv. Cigarette smoking, on the other hand, exposes the lungs to radioactive substances like polonium-210 and lead-210, which emit alpha and beta radiation internally. The cumulative radiation dose from smoking varies depending on the number of cigarettes smoked, but estimates suggest that smoking one pack (20 cigarettes) per day for a year results in an effective radiation dose of about 160 mSv to the lungs. Breaking this down, one cigarette roughly corresponds to about 0.02 mSv of radiation dose to lung tissue.
Using these figures, the 2 mSv from 5 mammograms equates to the radiation dose from approximately 100 cigarettes (2 mSv ÷ 0.02 mSv per cigarette = 100 cigarettes). Some sources suggest a slightly higher or lower equivalence depending on assumptions about radiation distribution and biological impact, so the range can be roughly 100 to 200 cigarettes.
It’s crucial to emphasize that the type and location of radiation exposure differ significantly between mammograms and smoking. Mammograms deliver external low-dose X-rays targeted at breast tissue, while smoking causes internal radiation exposure primarily to lung tissue due to inhaled radioactive particles. The biological effects and cancer risks from these two sources are not directly comparable just by dose alone because of differences in radiation type, tissue sensitivity, and exposure duration.
Mammography radiation doses are very low and considered safe for routine breast cancer screening, especially when weighed against the benefits of early cancer detection. The radiation risk from mammograms is minimal compared to the well-established high risks of smoking, which causes lung cancer and many other diseases through multiple harmful mechanisms beyond radiation.
In summary, while 5 mammograms expose you to about the same amount of radiation as smoking around 100 to 200 cigarettes, the health risks from mammogram radiation are far lower than those from smoking because of the differences in radiation type, exposure route, and overall biological impact. This comparison is mainly useful to help people understand the relative scale of radiation doses rather than to equate the health risks directly.
