OBJECTIVES: This paper presents toxic effects of 2-MN in laboratory animals under conditions of 4-week inhalation exposure to 2-methylnaphthalene (2-MN) vapors. MATERIALS AND METHODS: Male Wistar rats were exposed to 2-MN vapors at a nominal concentration of 0, 2, 10 or 50 mg/m(3) in dynamic inhalation chambers for 4 weeks (6 h/day, 5 days/week). After 4 weeks of inhalation exposure the animals were necropsied. Blood samples were collected and selected organs were weighted and prepared for histological examinations. RESULTS: The effects of the increased levels of exposure to 2-MN experienced by the experimental rats were as follows: a) increasing γ-glutamylotransferase activity, b) stimulation of the hematopoietic system, c) lower cholesterol concentrations, d) higher number of goblet cells in lobar bronchi, e) hyperplasia of hepatic bile ducts. CONCLUSION: Four-week exposure of the animals to 2-MN at 2 mg/m(3) proved to be the no-observed-adverse-effect-level (NOAEL), while 10 mg/m(3) appeared to represent the lowest-observed-adverse-effect-level (LOAEL).
OBJECTIVES: This paper presents toxic effects of 2-MN in laboratory animals under conditions of 4-week inhalation exposure to 2-methylnaphthalene (2-MN) vapors. MATERIALS AND METHODS: Male Wistar rats were exposed to 2-MN vapors at a nominal concentration of 0, 2, 10 or 50 mg/m(3) in dynamic inhalation chambers for 4 weeks (6 h/day, 5 days/week). After 4 weeks of inhalation exposure the animals were necropsied. Blood samples were collected and selected organs were weighted and prepared for histological examinations. RESULTS: The effects of the increased levels of exposure to 2-MN experienced by the experimental rats were as follows: a) increasing γ-glutamylotransferase activity, b) stimulation of the hematopoietic system, c) lower cholesterol concentrations, d) higher number of goblet cells in lobar bronchi, e) hyperplasia of hepatic bile ducts. CONCLUSION: Four-week exposure of the animals to 2-MN at 2 mg/m(3) proved to be the no-observed-adverse-effect-level (NOAEL), while 10 mg/m(3) appeared to represent the lowest-observed-adverse-effect-level (LOAEL).
Authors: Zheng Li; Lovisa C Romanoff; Debra A Trinidad; Erin N Pittman; Donald Hilton; Kendra Hubbard; Hasan Carmichael; Jonathan Parker; Antonia M Calafat; Andreas Sjödin Journal: Anal Bioanal Chem Date: 2014-04-09 Impact factor: 4.142