Chronic inhalation exposure of rats for up to 104 weeks to a non-carbon-based magnetite photocopying toner.
Int J Toxicol
; 27(6): 427-39, 2008 Nov.
Article
en En
| MEDLINE
| ID: mdl-19482822
Male and female Han Wistar rats were exposed for 6 h/day, 5 days/week for 13 or 104 weeks (whole body) to a magnetite photocopying toner. The toner contained 45% to 50% magnetite, with 45% to 50% styrene acrylic resin and less than 5% external additives, including hydrophobic amorphous silica and proprietary surface functional modifiers. Exposure levels were 1, 5, and 25 mg/m(3) for the 13-week study and 1, 4, and 16 mg/m(3) for the 104-week study. Lung toner burdens averaged 36, 288, and 604 microg per lung after 104 weeks' exposure at 1, 4, and 16 mg/m(3). The lung burdens were lower than have been reported in a similar study with a carbon-based toner. There were no significant effects on weight gain or food consumption in either study, or on clinical pathology parameters examined in the 13-week study. After 104 weeks' exposure at 16 mg/m(3), macroscopic examination revealed dark discoloration of the lungs and associated lymph nodes. Lung weights were significantly elevated by 21% and 14% for male and female rats, respectively. Microscopic findings indicative of a mild inflammatory response were similar in both studies, and included the presence of black-pigmented macrophages in the lungs and tracheobronchial and mediastinal lymph nodes; increased incidences of perivascular/peribronchiolar inflammatory cell infiltration; inflammation of the alveolar ducts (characterized by aggregations of black-pigmented alveolar macrophages and interstitial lymphocytic infiltration); increased cellularity of the bronchiole-associated lymphoid tissue; and a few instances of alveolar ciliated metaplasia. The 104-week study showed no increase in the incidence of pulmonary tumors.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Óxido Ferrosoférrico
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Int J Toxicol
Asunto de la revista:
TOXICOLOGIA
Año:
2008
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos