THE CADMIUM CONTENT OF BRITISH WHEAT-GRAIN

The Cd content of wheat (Triticum aestivum L.) grain samples collected representatively from the major wheat growing regions of Britain in 1982, 1992, and 1993 was measured. Geographical distributions of grain Cd content were compared with the total Cd concentration in soils of England and Wales. The ranges and mean grain Cd concentrations for 1982, 1992, and 1993 were (mg kg(-1) dry weight, DW) 0.016 to 0.18, mean 0.052; 0.008 to 0.27, mean 0.042; and 0.004 to 0.31, mean 0.038, respectively. There was about a 20% decrease in mean grain Cd concentration from 1982 to 1992-1993. The proportion of samples above the World Health Organization's (WHO) limit of 0.12 mg Cd kg(-1) DW was 4% for 1982 and 1992 and 2% for 1993. The geographical distribution of these high Cd grain samples corresponded with areas where the total soil Cd concentrations were significantly above background concentrations. Differences between wheat varieties were small and significant (P < 0.001) only for 1992. The concentration of Cd in white flour was significantly correlated with that in wholemeal hour (r = 0.95), and bran Cd was significantly correlated with white hour Cd (r = 0.87). On average, the concentration of Cd in bran was twice that in wholemeal hour, and white flour contained about 31% less Cd than wholemeal flour. The estimated daily dietary Cd intake in the United Kingdom (UK) through the consumption of wheat-based products was about 8 mu g Cd per person or about 11% of the WHO's limit of 70 mu g Cd d(-1). The Cd content of the vast majority of British wheat grain would not constitute a health hazard to the population of the UK or elsewhere.