Being board-certified means that in addition to going to medical school and doing a residency in family medicine, a doctor has also passed an additional rigorous examination.
Silicosis (previously miner's phthisis, grinder's asthma, potter's rot and other occupation-related names) is a form of occupational lung disease caused by inhalation of crystalline silica dust, and is marked by inflammation and scarring in the form of nodular lesions in the upper lobes of the lungs.
Another example of harmful dust generated is flue dust, a byproduct of mining fluorine. According to the Chinese Society of Rare Earths, every ton of REE produced generates 8.5 kilograms of fluorine and 13 kilograms of flue dust, waste materials which contain the heavy metals discussed above (Schuler et al, 2011).