Residue levels of an organochlorine insecticide, BHC, were determined for brown rice samples produced in Korea by collection and field experiments to obtain the following results.
1) Residue levels of total BHC in 112 samples (an Indica type variety Tongil) produced in 1976 and collected from 9 provinces in proportion to the production level of rice ranged from 0.0010 to 0.0762 ppm, the average being 0.0061 ppm.
2) The residue levels in samples from Jeonbook, Iiyongnam and Choongnam provinces were higher than the average for whole samples. BHC isomers were found in the order of α$gt;γ$gt;β$gt;δ isomers, and the detection frequency by range were 89.3% below 0.01 ppm, 9.8% for 0.01∼0.05 ppm and 0.9% for 0.05∼0.10 ppm.
3) In field experiments according to conventional agronomical practices, the brown rice samples after spraying of BHC at the first generation time of rice stem borer (4 ㎏ of 6% granular formulation/10 a paddy field) showed a little higher residue level than control samples, but not more than 0.035 ppm, whereas samples after spraying at the second generation time (3 ㎏/10 a) contained in the range of 0.04∼0.19 ppm.
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