Bone cadmium and lead in prehistoric inhabitants and domestic animals from Gran Canaria.

Both lead and cadmium exposures derive from natural sources and also from industrialisation and certain habits, such as cigarette smoking in the case of cadmium. Some of these sources only affect human beings. The aim of this study was to determine the levels of lead and cadmium in bone samples of 16 prehispanic inhabitants of Gran Canaria, 24 prehispanic domestic animals (sheep, goat and pigs) from this island, 8 modern individuals, and 13 modern domestic animals. We found that modern individuals showed higher bone Cd values (mean=516.7+/-352.49 microg/kg, range=167.20-1125 microg/kg) than prehistoric ones (mean=85.13+/-128.96 microcg/kg, range=2.97-433 microg/kg). Values of prehistoric individuals did not differ from those of the prehistoric animals (mean=70.54+/-46.86 microg/kg, range=11.06-216.50 microg/kg), but were higher than those of the modern animals (mean=7.31+/-10.35 microg/kg, range=0-35.62 microg/kg). In the same way, modern individuals and modern animals showed approximately 7-fold higher bone Pb than ancient individuals and ancient animals, respectively. Ancient animals showed significantly lower Pb values than all the other groups, whereas modern animals showed Pb values comparable to those of the ancient individuals. A significant correlation was observed between bone Pb and Cd (r=0.61, P<0.001). Since bone cadmium accumulation leads to osteoporosis, we have also tested the relationship between histomorphometrically assessed trabecular bone mass and bone cadmium both in modern and ancient individuals. No significant relationship was found between these two parameters.