Cocarcinogenicity of foundry silica sand in hamsters.
Niemeier RW; Mulligan LT; Rowland J
Silica, silicosis, and cancer: controversy in occupational medicine. Goldsmith DF, Winn DM, Shy CM, eds. New York: Praeger, 1986 Jan; :215-227
The cocarcinogenicity of foundry silica sand was investigated in hamsters. Respirable size particulates, obtained from commercial samples of foundry silica sand, ferric-oxide (1309371), and Min-U- Sil (14808607), a reference quartz, were administered in saline by intratracheal instillation to groups of 50 male Syrian-golden- hamsters. Hamsters received 15 weekly administrations of either particulate alone or particulate plus 3 milligrams benzo(a)pyrene (50328) (BaP). The hamsters were killed when moribund or at 92 weeks after the first treatment, and tissue were examined for histopathologic changes. The principal treatment effects were respiratory tract tumors, which were observed in every group receiving the BaP. Tumor incidences in the silica sand/BaP and Min- U-Sil/BaP groups were significantly greater than that in the saline/BaP group but did not differ from that in the ferric- oxide/BaP positive control group. Mean percent of lung tumor bearing animals ranged from 47 for the saline/BaP group to 90 for the Min-U-Sil/BaP group. Mean latency ranged from 67 to 70 weeks for the ferric-oxide/BaP, silica sand/BaP, and Min-U-Sil/BaP groups to 73 weeks for the saline/BaP group. Squamous cell carcinomas, adenosquamous carcinomas, and adenocarcinomas of the lungs and bronchi were the tumor types most commonly found. The saline control group had no respiratory tumors. Of the groups given particulates without BaP, only the ferric-oxide (incidence, 1/41) and Min-U-Sil (incidence, 1/50) groups developed respiratory tract tumors. Pulmonary fibrosis was not observed, but granulomatous inflammation occurred at a significantly increased rate in groups given silica sand or Min-U-Sil.
NIOSH-Contract; NIOSH-Author; Carcinogens; Laboratory-animals; In-vivo-studies; Silica-dusts; Iron-oxides; Quartz-dust; Pulmonary-system-disorders; Lung-cancer
1309-37-1; 14808-60-7; 50-32-8
Goldsmith DF; Winn DM; Shy CM
Silica, silicosis, and cancer: controversy in occupational medicine