Wronkiewicz SK, Roggli VL, Hinrichs BH, et al. - Six human papillomaviruses (HPV)-negative laryngeal (n = 4) and pharyngeal (n = 2) squamous cell carcinoma (SCC) individuals with a history working in an asbestos-exposed occupation were recruited from a large population-based case-control study of head and neck cancer by the experts in order to strengthen existing evidence through empirical illustration of persistent asbestos fibers embedded in the tissue surrounding laryngeal and pharyngeal SCC, therefore giving a more definitive biological connection between exposure and disease. All three individuals had tumors arising in the larynx. Moreover, a wollastonite fiber of unclear importance was recognized as one of the HPV-negative pharyngeal SCC individuals. In adjacent tissue of the individuals without occupational exposure, no mineral fibers were recognized. in individuals with a history of occupational asbestos exposure, the presence of asbestos fibers in the epithelial tissue surrounding laryngeal SCC added a principal line of physical proof involving asbestos as an etiologic factor.