more than two thirds ( from 70.3 to 75.6 per cent ) of the samples were shown to be free of p ' p ' dde , p ' p ' ddt , and dieldrin , and more than one third ( from 35.1 to 43.2 per cent ) -- of alfa and gamma hexachloran , heptachlor and heptachlorepoxide .
C0019219
heptachlor
C0019220
heptachlorepoxide