【摘要】 <正> 有机氯农药六六六(BHC)在土壤中的持留性已有大量的研究,并认为它在土壤中十分稳定,不易被降解,残留时间较长,可积累在土壤中,长期使用六六六会造成土壤污染,因此使得这种农药的生产和使用受到了限制。但在六十年代以后,很多报道部指更多还原

【Abstract】 Three hundred and fifty paddy soil samples collected from representative districts of China were studied. The analytical results showed that the content of BHC remained in the plowed layer (1—15 cm) ranged from 0.021 to 1.96 ppm with an average of 0.307 ppm. In 83.1% of samples, the residue of BHC in soil was less than 0.5 ppm.The sequence of the residues of four isomeric BHC were in the order of β>α>δ>γ. Experimental results showed that under the submerged conditions these isomers were degradated rapidly and almost disappeared within two months.The analytical results of 25 samples of brown rice showed that correlation between the content of BHC in brown rice and its residue in soil after harvest was not significant (r=0.379). However, the content of BHC in brown rice was increased with the increase of the amount of applied BHC in growing season of the rice. Its correlation coefficient r=0.68 and the significance amounts to 99%.更多还原