Proposed criteria for mixed-dust pneumoconiosis: Definition, descriptions, and guidelines for pathologic diagnosis and clinical correlation1 1The NIKKO-Symposium on Mixed-Dust Pneumoconiosis was held October 18–19, 1997, in Nikko, Tochigi, Japan, to develop diagnostic criteria for mixed-dust pneumoconiosis under the auspices of Labour Welfare Corporation, Tokyo, Japan. The Organizing Committee included Keizo Chiyotani, Koichi Honma, Yutaka Hosoda, and Hisao Shida, and participants included Zoltán Adamis, Eduardo Algranti, Toshiharu Fuyuki, Kiyonobu Kimura, Otha Linton, Michihito Mishina, Hiroshi Morikubo, Alvaro R. Osornio-Vargas, Yoshiaki Saitoh, Yasushi Shinohara, and Hiroshi Watanabe.