Hello there,
Multiple fibrocalcific infiltrates can be due to a variety of conditions but are most common in people who live near areas or are engaged in occupations that deal with fine particulate matter. This will include coal mines, agricultural work, glass workers, sand mining. The reason that it can be used by employers to reject your application is because they may indicate the person is predisposed to respiratory illness like tuberculosis or interstitial disease in the future. It can be removed as a lobectomy(I.e they remove a part of your lung by surgery) but that involves some risk. Also if your application has been rejected once they will not accept your reapplication that easily.
I know this seems unfair but sometimes it happens.
Please feel free to address any further queries to me,