Seen in current ct of chest, previous ct in sept 2022 these were not seen: pleural based oval shaped nodular density 8.6 mm in right lower lobe. an 8 pleural based nodular density posteriorly in left lower lobe 4.4 mm. is this concerning?

They are very small-too small to biopsy. Often, these end up being inflammatory nodules that will go away; sometimes new ones will appear. If you are smoking, you should quit ASAP. These will need to be followed so you should probably be re-scanned in about 3 months or so. If they haven’t changed, then the scan occurs again 6 months later and then a year after that, if there are no changes.