The insecticide malathion (57% E.C.) was applied at the rate of 712.5 gm active ingredient per feddan on dill, Anethum graveolens L. and coriander, Corianderum sativum L. for controlling aphids infesting these plants. An analytical method, using gas chromatography equipped with flame photometric detector was used for detecting the insecticide residues. A field trial was conducted to determine the rate of dissipation of malathion in dill and coriander plants and in the resulting oil. Residue analysis showed that the initial deposits determined one hour after application were 35.81 & 22.7 ppm in dill and coriander plants, respectively. Rates of dissipation of malathion were 4.72, 51.1, 68.39, 88.41 and 93.49% in dill plants and were 13.61, 43.22, 66.78, 86.26 and 91.85% in coriander plants at 1, 3, 7, 14 and 21 days post treatment, respectively. The pesticide was decayed quite rapidly in and on dill and coriander plants and detectable residues (1.62 and 0.93 ppm) were observed in these plants 28 days after treatment. At harvest 46 days for coriander and 70 days for dill after application malathion was found at average levels of 0.78 mg/kg and 0.54 mg/kg in dill and coriander dry seed, respectively. The volatile oil extracted from the seed by steam distillation process was contaminated with the insecticide at a higher levels than in the seed [about sevenfold in dill oil, 5.21 mg/kg and ninteenfold in coriander oil 10.16 mg/kg]. This means that malathion had tendency to co-distill with the dill and coriander oil throughout steam distillation process.

In present set of investigations the chemoprotective effect of green tea and ginger extracts has been evaluated using in vivo chromosomal aberrations assay in albino mice (Mus musculus). The organophosphate agropesticide malathion, 80% technical grade consider as a potent genotoxic agent, was given at a single dose 230 mg/kg b.w. (1/12 LD50) intraperitoneally. Pretreatment with 4 and 3% of freshly prepared green tea (GTI), ginger (GI) extracts, respectively and the mixture of both extracts (GTI+GI) were given through oral incubation for 6 days prior to malathion administration. Animals from all the groups were sacrified at sampling times of 24 and 48 hours and their bone marrow cells were analyzed for chromosomal damages. The animals of the positive control group (Malathion alone) showed a significant increase in chromosomal aberrations both at 24 and 48 h sampling time. The green tea and ginger extracts, alone did not significantly induced aberrations at either sampling time, conforming their non-mutagenicity. However, significant suppressions in the chromosomal aberrations were recorded following pretreatment with green tea and ginger extracts administration. The antigenotoxic effects of both extracts separately and in mixture were also evident, as observed by significant increase in mitotic index, when compared to positive control group. Reduction in malathion induced clastogenicity by both extracts, was evident at 24 h and to a much greater extent at 48 h of cell cycle. Thus results of the present investigations revealed that green tea and ginger extracts have chemoprotective potential against malathion induced chromosomal mutations in albino mice.