Clearance of exp 59 Fe sub 3 O sub 4 Particles from the Lung of Rats during Exposure to Coal Mine Dust and Diesel Exhaust

摘要

Experiments in rats were performed to investigate the influence of diesel/coal dust exposure on lung clearance of inert tracer particles. Four groups of 80 rats each were exposed as follows: (1) Coal mine dust, 2 mg/m exp 3 ; (2) Diesel exhaust, 2 mg/m exp 3 ); (3) Coal mine dust (1 mg/m exp 3 ) plus diesel exhaust (1 mg/m exp 3 ); (4) Filtered air (control). The exposure was for 7 hours per day, 5 days per week for a period of 6 months. Two months after commencement of the study, all animals were exposed in nose only exposure units to exp 59 Fe sub 3 O sub 4 dust for 2 hours. Lungs of serially killed animals were excised and their exp 59 Fe activity measured. Biological half lives of long term clearance of Fe sub 3 O sub 4 from the lung were 47 days (controls), 42 days (coal), 43 days (coal/diesel) and 37 days (diesel). exp 59 Fe sub 3 O sub 4 retention on day 120 was significantly lower in all exposure groups as compared to controls, with the diesel group showing the lowest retention (< 50% of controls). Short term clearance determined from Fe sub 3 O sub 4 retention of day 1 was not significantly different between the groups. 11 references. (ERA citation 09:001343)