Elevated lead concentrations in edible portions of game birds harvested with lead shot

摘要

Here, we report the results of a study to determine the frequency of elevated Pb concentrations in pectoral muscle tissue of hunter-killed game birds (mostly waterfowl), and to address the cause of occasionally observed high Pb values. Of 827 right pectoral muscle pools (1-12 individuals per pool), 92 had Pb concentrations greater than 0.5 mu g/g wet weight, (similar to 2 mu g/g dry weight). The average Pb concentration for these 92 pools was 12 +/- 38 mu g/g wet weight (similar to 40 +/- 125 mu g/g dry wt). When tissue from individuals making up some of these 'high Pb' pools were analysed, 40 of 190 individual birds had Pb concentrations > 5 mu g/g dry weight in their right pectoral muscles. All tissue samples were examined visually prior to analysis, and none contained detectable Pb pellets. The average concentration of Pb in right pectoral muscle tissue of individual birds from high Pb pools with elevated muscle-Pb concentrations was 211 +/- 634 mu g/g (n=40) and ranged from 5.5 to 3910 mu g/g (dry wt). Large differences in Pb concentrations between right and left pectoral muscle of the same individuals, were often noted. The magnitude of the differences in Pb concentrations between left and right pectoral muscles of the same individual, and also between different samples taken from the same tissue, preclude both analytical error and biologically incorporated Pb as the cause of the elevated Pb concentrations in these animals. Radiography confirmed the presence of numerous small (< 1 mm diameter) metallic fragments in pectoral muscle samples from these birds. Embedded fragments of metallic Pb from shot disintegration are a potential source of dietary Pb exposure for predators, and for human consumers of wild game, especially in communities that rely on subsistence hunting and for whom hunter-killed wild game represents a major food source. This risk can be eliminated by the use of non-toxic shot for hunting. Crown copyright (C) 1998 Published by Elsevier Science Ltd. All rights reserved. References: 14