臺灣農藥科學第一期

三種農藥之多重混合毒性

Evaluation of Imidacloprid, Hexaconazole and

Chlorothalonil Three Pesticides Mixture Toxicity

Effects

Chun-Hung Yang

* , Tian-Yu Lin

, Wei-Ren Tsai

Abstract

Yang, C. H., Lin, T. Y., and Tsai, W. R. 2016. Evaluation of imidacloprid, hexaconazole and chlorothalonil

three pesticides mixture toxicity effects. Taiwan Pestic. Sci. 1: 1-23.

Pesticides are indispensable to agriculture as they protect plants from disease and improve

agricultural production. However, pesticides are associated with cumulative or mixture risks

when excessive amounts of mixed pesticide residues are ingested (typically from consuming

fruits and vegetables). Therefore, comprehensive risk assessments of pesticide mixtures are

critically important. Previous studies have shown that imidacloprid, hexaconazole, and

chlorothalonil pesticides can induce neurotoxic, hepatotoxic, and nephrotoxic reactions,

respectively. The present study addresses the mixed neurotoxic, hepatotoxic, and nephrotoxic

effects of imidacloprid, hexaconazole, and chlorothalonil by combining these three pesticides

(which act independently and have different toxicity modes of action) in a 28-day oral subacute

toxicity assay. Treating rats with a combination of 75 mg/kg/day imidacloprid (about 1,250

fold of ADI), 150 mg/kg/day hexaconazole (about 30,000 fold of ADI), and 200 mg/kg/day

chlorothalonil (about 6,700 fold of ADI) induced simultaneous clinical sign of convulsions,

hepatocyte vacuolations (fatty changes), and reductions in ALT levels. However, there is no

evidence that exposure to the combination of these three pesticides can aggravate clinical

convulsions, hepatocyte vacuolations, or ALT level hepatotoxicity caused by exposure to a

single pesticide or different combinations of two pesticides. Our findings demonstrate that the

combination of imidacloprid, hexaconazole, and chlorothalonil pesticides do not have dose

additive (cumulative) or synergistic effects in rats.

Key words:

interaction, synergy, mixtures, dose additivity, accumulation risk assessment,

antagonism.

Accepted: September 10, 2016.

* Corresponding author, Email:

Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture. Taichung.