What Causes Pulmonary Nodule In Left Lung?

Question : I had a Calcium Scoring test last week & am surprised and concerned about the results. I’m a healthy 66 yr old tall, thin, active female, never smoked. I grew up in a home where my father smoked and was exposed to 2nd hand smoke growing up and during a marriage till I was age 32. No regular exposure to 2nd hand smoke since then.

I am concerned about the Radiologist report which states:

“There is a small 2 to 3 mm pulmonary nodule along the lateral aspect of the mid left lung. Nodules as small as this typically do not require follow-up unless patient has a strong smoking history, in which case a one year noncontrast chest CT could be considered. Normal aeration of the lung. The esophagus, mediastinum, and bilateral hila are all within normal limits. There is some fat along the medial aspect of the inferior portion of the right lower lobe near the pleural surface.”

The radiologist does not say if the nodule looks calcified or spiculated. A recent URI with viral bronchitis is mostly resolved after 2 months of coughing – could the nodule be from that infection?
How concerned should I be about this pulmonary nodule? I have read that there is some irisk of cancer from the radiation in a calcium scoring CT scan. How much cancer risk is there from getting another CT scan as a follow-up, in a year for example?

Do you agree with radiologist recommendation of no f/up needed?