Assessment of anilofos-induced mutagenicity in bone marrow and germ cells of Swiss albino mice

Anilofos is an organophosphate compound and is used extensively as a preemergence and early postemergence herbicide for the management of sedges, annual grasses, and some broad-leaved weeds in rice fields. The present study was aimed to assess the mutagenic potential of anilofos after sub-chronic exposure in Swiss albino mice. For this, a combined approach employing micronucleus (MN), chromosomal aberration (CA) studies and sperm-head abnormalities (SHAs) was used. Three dose levels of 1%, 2%, and 4% of maximum tolerated dose (MTD) (235 mg/kg b.wt.), that is, 2.35, 4.7 and 9.4 mg/kg b.wt., respectively, were administered orally daily for 90 days. A higher incidence of micronucleated erythrocytes (polychromatic erythrocytes + normochromatic erythrocytes), significant increase in CA frequency, and significant decrease in the ratio of polychromatic/normochromatic erythrocytes (P/N) ratio were observed at the 4.7 and 9.4 mg/kg b.wt. dose levels. A significant increase in SHA was observed in all treatment groups (2.35, 4.7, and 9.4 mg/kg b.wt.) from the control group. In conclusion, anilofos exposure of 2% and 4% of MTD caused a higher rate of micronucleated erythrocytes, increased frequency of CA, increase in SHA, and lower P/N ratio, and pesticide exposure of 1% of MTD only resulted in higher SHAs. Thus, anilofos was found to have mutagenic potential in mice when administered daily orally at dose rate of 4.7 and 9.4 mg/kg b.wt. for 90 days.

Potential cytotoxic effect of Anilofos by using Allium cepa assay

Cytogenetic effects of Anilofos which was widely used in agriculture, was evaluated in Allium cepa root meristematic cells. In the Allium root growth inhibition test EC50 value was determined 50 ppm and 1/2× EC50 (25 ppm), EC50 (50 ppm) and 2 × EC50 (100 ppm) concentrations of Anilofos were applied to onion roots. A negative and positive control were used in the experiment in parallel. According to results mitotic index decreased with increasing the Anilofos concentrations in all application groups and each exposure time, while disturbed anaphase-telophase, choromosome laggard(s), stickiness and anaphase bridge(s) were observed. In anaphase-telophase cells, c-metaphase, disturbed nucleus and binuclear cells were observed in other anomalies. The results were also analyzed statistically by using Dunnett t test (2-tailed) and all concentrations of Anilofos were found significant.

Degradation kinetics of anilofos in soil and residues in rice crop at harvest

BACKGROUND

Pesticides used on rice, which is widely grown in India in the rainy season, must be investigated for the persistence and magnitude of their residues in the crop and soil to ensure human and environmental safety. Anilofos is widely used in rice, and its persistence and dissipation behaviour in soil and rice was investigated in field trials under subhumid and subtropical conditions.

RESULTS

The persistence of anilofos in soil, husk, grain and rice straw was evaluated at two application rates (0.4 and 0.8 kg AI ha(-1) ) by RP-HPLC. In soil, residues were detected up to 45 and 75 days after application at 0.4 and 0.8 kg AI ha(-1) respectively. No residue was observed in soil, husk, grain or rice straw at the time of harvest at either application rate. Detector response was linear within the concentration range 0.1-5.0 µg mL(-1) at 2.22% standard deviation. The limit of detection was 0.003 µg mL(-1) , and the limit of quantification of the method for soil, straw, grain and husk was 0.007, 0.01, 0.008 and 0.01 µg g(-1) respectively.

CONCLUSION

The dissipation of herbicide from soil appeared to occur in a single phase and conformed to pseudo-first-order kinetics. The calculated half-life values of anilofos residue in soil were 13 days for the lower rate of application (0.4 kg AI ha(-1) ) and 15.5 days for the higher rate (0.8 kg AI ha(-1) ). Anilofos residues were below the maximum residue level in soil, husk, rice grain and rice straw at harvest.