Inhalation toxicity studies of Thimet ( Phorate) in the male swiss albino mouse, Mus musculus: II. Lung histopathology, pseudocholinesterase level and haematological studies

Abstract

Sub-chronic exposure of the male swiss albino mouse, Mus musculus to the recommended field dose of Thimet (Phorate; 6728.5 mg m −3) in a whole-body inhalation chamber was studied on the 2nd, 4th, 6th, 8th, 10th and 12th week of exposure. A significant depression of pseudocholinesterase (Che) level was observed throughout the experimental period. A significant decrease in haemoglobin concentration (Hb conc.), red blood corpuscle count (RBC) count and packed cell volume percent (PCV%) was observed from the 6th week of exposure until the end of the experiment. Total leucocyte count (WBC count) showed a significant rise in the 2nd week of exposure (this rise was due to the rise in the monocyte and neutrophil counts), and later from the 6th week onwards showed a significant decrease until the end of the experiment (the decrease was mainly due to the fall in the lymphocyte count). The lung in the exposed animals showed various degrees of bronchopneumonia, emphysema and collapse throughout the experiment. After a 30 day recovery period almost all the blood parameters were back to the normal levels, except the total leucocyte count which showed a higher level than the normal count. However, the lung in the recovered animals showed emphysematous changes but no bronchopneumonia and inflammation. The results suggest that inhalation of the pesticide, Thimet could cause damages to Mus musculus, it also suggest that the improper handling and usage of this pesticide by human beings could affect their well being and efficiency at work.