Sub Chronic Inhalation Toxicity Studies of 2,2-Dichlorovinyl Dimethyl Phosphate (DDVP) in Albino Rats

60 adult Rattus novergicus (both sexes) of mean body weight of 150.0±3.5g were distributed into six groups of ten rats per group (same sex). The groups A, B, C, D, E and F were exposed to adjusted dosages of 0%, 20%, 40%, 60%, 80% and 100% of DDVP respectively by inhalation from day 1 to day 28. Biochemical analysis indicated that DDVP caused significant decrease (p<0.05) in GPT activity, WBC and lymphocytes levels in exposed groups while GOT activity, creatinine, haemoglobin, PCV and neutrophil levels were significantly increased. ALP activity was unchanged in groups exposed to 20%; decreased in groups exposed to 40%, 60% 80% while significant increase was observed in group exposed to 100% DDVP. Albumin was also significantly increased in groups exposed to 80% and 100% DDVP. Groups exposed to 0%, 20% and 40% DDVP showed GOT/GPT ratios <1 while >1 was the value obtained for groups exposed to 60%, 80% and 100%. Groups exposed to 0%, 20% and 40% DDVP showed weight gain while weight loss was recorded in group exposed to 100% DDVP throughout the experimental period. Investigated parameters were generally higher in group F (exposed to 100%) than other groups. Severe toxicity was observed in group exposed to 100% DDVP after 21 day of continuous exposure. Cholinergic signs observed in severely affected group that was exposed to st 100% DDVP included anorexia, muscular tremors, mucous nasal discharges, increased frequency of salivation and urine staining, decreased body weight gain and diarrhoea. No adverse effects or cholinergic signs were observed in the functional observational battery and locomotors of the rats exposed to 0% to 80%; the NOEL was determined to be 20%. No mortality was recorded and none was killed because of intoxication. The leukopenia, lymphocytopenia, neutrophilia, increased haemoglobin, albumin and creatinine established in this study resulted from increased DDVP concentration and were attributed to malnutrition from low feed intake and dehydration.