Asbestosis in a Japanese Macaque (Macaca fuscata)

Asbestosis is a chronic lung disease caused by inhalation of asbestos, a fibrous mineral. It is one of the most severe diseases resulting from environmental contamination. We found asbestosis in a female Japanese macaque over 25 years of age that died from senility. Clear needle-like crystals were deposited throughout the lung lobes, particularly in the perivascular areas. Asbestos bodies were observed in some of these crystals. Fibrosis without inflammation was observed in the periarterial and peribronchiolar regions. The crystals were identified as tremolite, and a total of 16,633,968 asbestos bodies and 465,334,411 tremolite fibers were observed in 1 g of dry lung tissue. No tumors or pleural adhesions were seen. This is the first report of spontaneous asbestosis in a nonhuman animal.