Pesticide residues in foodstuffs in Great Britain: X.—Bromide residues in maize, pulses and nuts

Abstract

Results are presented for the determination of bromide residues in maize, in pulses and in four types of nuts sampled on arrival in British ports mostly during the five years up to June 1968. In the maize, which had been fumigated in the ships' holds before export, 75 "/, of the 155 samples examined contained less than 50 ppm but some contained more than 200 ppm. The problems of fumigating bulk maize and the extent to which variations in bromide residue are evened out during grain handling operations in the port granary are discussed. The samples of pulses generally contained less than 50 ppm but some samples of haricot beans contained more than 100 ppm. Out of 164 samples of groundnuts from 11 countries only one contained more than 200 ppm. Those containing more than 100 ppm came from countries in which nuts are sometimes fumigated more than once. None of the walnuts or almonds examined contained more than 100 ppm but two samples of Brazil nuts had more than this.Results are also presented for the increase in bromide residue after the fumigation of consignments in Britain and the reasons for the wide variations observed are discussed. IntroductionA ready penetration into foodstuffs, coupled with a high toxicity to insects makes methyl bromide an excellent fumigant for infested foodstuffs and it is widely used for this purpose in many countries. Most of the fumigant is quickly removed when the goods are aired at the conclusion of the fumigation period but some fixed bromide remains, resulting from the reaction of methyl bromide with the food constituents. The quantity varies with the nature of the foodstuffs, the dosage applied and such other factors as the moisture content and