Pneumonovolcanosilicosis is from silicosis cause by silica from volcanic ash (silicon dioxide)
Pneumonoultramicroscopicsilicovolcanoconiosis is fibrotic lung diseases of the pulmonary parenchyma following chronic inhalation of inorganic dusts containing crystalline silicon dioxide. The acute manifestations observed after heavy ashfalls include attacks of asthma and bronchitis, with an...
pubmed.ncbi.nlm.nih.gov
Silicosis is the more general lung disease caused by silica (of any source).
Silicosis is a fibrotic lung disease caused by inhalation of free crystalline silicon dioxide or silica. Occupational exposure to respirable crystalline silica dust particles occurs in many industries. Phagocytosis of crystalline silica in the lung causes lysosomal damage, activating the NALP3...
pubmed.ncbi.nlm.nih.gov
My father died secondary to Silicosis from damage done to his lungs when he was a young hard rock miner. Although he left the profession at 19 it had damaged his lungs so badly that later in life it was partially responsible. So please whatever you call it use a mask when handling DE, or perlite or any dust.