ABSTRACT
Toxicity data with single pesticides to test animals are far more abundant than with mixtures [Flipo et al., 1992]. Consequently, these data cannot be used directly to predict the effect of pesticide combinations. Three pesticides; imidacloprid, profenofos and carbosulfan, administered to rats per OS at low level dose equal 1/30 LD50 for each insecticide, which represent 111, 70 and 43 ppm, respectively on homeostasis status and haematological indices [El-Kashory and El-Said, 2001], were selected to explore their combined action of subchronic exposure studies for 90 days in adult male albino rats. Homeostasis-related parameters such as; aldosterone [Ald.], sodium ions [Na+], potassium ions [K+], total chloride ions [T.Cl-] levels, pH value and haematological indices were examined in rats after an administration with different insecticide combinations. Moreover, after withdrawal the pesticide combinations for 30 days, as a recovery period, the above mentioned parameters were evaluated, in comparison with the control group. Results showed that, pesticide combination imidacloprid/profenofos [I + P] induced significant decrease in Na+ and T.Cl- ions levels and significant increase in pH value. While, it did not alter both Ald. and K+ ions levels. Combination imidacloprid/carbosulfan [I + C] increased significantly Ald., T.Cl- ions levels and pH values. On the contrary, it reduced Na+ and K+ ions levels significantly. Combination of profenofos/carbosulfan [P + C] decreased Ald. and Na+ significantly, while, K+ and T.Cl- level and pH value did not alter. In addition, tri-combination imidacloprid/ profenofos/carbosulfan [I + P + C] increased Na+ and T.Cl- ions level and pH value; while, a marked decline in Na+ ions level was occurred, as well as, no appreciable changes in K+ ion levels were observed. The combinations of I + P and I + C caused erythropenia [reduced RBC mass] associated with a significant decrease in PCV in I + C-treated rats. While, di-combinations P + C, I + P and I + P + C tri-combinations increased markedly of PCV and MCV. However, leukocytosis [elevated WBCS count] was observed in I + P + C-treated rats. After the pesticides combination withdrawal, changes in some parameters returned to the normal values, in comparison with the control group; while, the others still altered. Moreover, some parameters did not exhibit any changes unless after the stop of the treatment. In conclusion, this study supports the notion that; an interactions effects of pesticide combinations may be consider as contributor factor enhance their side effects