Pesticide residues in foodstuffs in Great Britain: A further report on the bromide contents of imported foods and feedingstuffs

Abstract

Results are presented for the determination of total bromide residues in cereals and cereal products, pulses, oilseed products, dried fruits, nuts and a variety of other products sampled in Britain during the 3‐year period July 1968 to June 1971. Of the 948 samples examined 801 (84%) contained not more than 100 mg/kg. bromide while only 20 samples (2 %) contained more than 200 mg/kg bromide. The highest residues were found in samples of nuts from India, South Africa and some East African countries and in some animal feedingstuffs.

The persistence of methyl bromide residues in rice, dried fruit, seeds and nuts following laboratory fumigation

“…Walnuts,11 pumpkin seeds3 and brown rice12 have previously been shown to contain MB residues and were therefore included, whilst white rice was selected for comparison with brown rice; similarly, brazil nuts and groundnuts were chosen for comparison with walnuts. The dried fruits were selected as commodities which can be fumigated on more than one occasion during storage 1…”

“…When food commodities are fumigated, a small proportion of the parent compound will react to form inorganic bromide residues, but residues of MB also persist. It is more difficult to determine MB residues than inorganic bromide residues because of the volatile and labile nature of MB; consequently, residue data associated with MB fumigations often quote the less toxic inorganic bromide levels 1. There is little information on MB residues in foodstuffs; Scudamore and Heuser2 have monitored MB residue levels following laboratory fumigation of stored products such as wheat, maize, flour, oats, rice, groundnuts, cocoa beans and sultanas, but residue data were restricted to a limit of detection of 0.1 mg kg −1 .…”

Potential hazards of fumigant residues.

“…In addition to bromine taken up by crops during growth, fumigation with bromine-containing compounds used to control pests during storage can also increase their br6mine content (82,83). As much as 40 mg Br/kg on a dry weight basis was sorbed by wheat grain and larger amounts by milled wheat products.…”

“…As much as 40 mg Br/kg on a dry weight basis was sorbed by wheat grain and larger amounts by milled wheat products. Bromine sorbed during fumigation in storage, when added to that derived from methyl bromide-treated soils during growth, could thus produce bromine contents greater than the recommended tolerance levels, even if grain at harvest contained substantially less (83).…”