talline material in macrophages in extracellular tissues adjacent to intrapulmonary airways and vasculature (see Fig. 1-41, B) . This finding is usually incidental in older animals, but coal dust and other mineral dusts, especially silica, 4 can elicit an inflammatory response with release of TNF-α and interleukin 1 (IL-1) and interleukin 6 (IL-6).