Active Pulmonary TB normally would be symptomatic. You seem to be asymptomatic. In that case the X-ray shadow seems to be an old scar/ calcification. However, as suggested by other doctors in the forum, get evaluated for any activity. The concern by your employer is right as active TB
is an infectious disease and an affected employee can spread it to other employees.
Rememeber that TB is an infectious disease. It spreads by spitting on roads and careless coughing by people in our society (including TB patients). TB has nothing to do with smoking
or family history. Lets take an example... If i drink contaminated water, I will get diarrhoea
. Has it anything to do with my family history or smoking history?