Bone lead content of the mid-tibia was measured by in vivo fluorescence excitation in 90 females and 59 males aged between 6 and 81. The cross-sectionally derived rate of increase of tibia lead content was 0.24 +/- 0.03 microgram [g mineral]-1 yr-1. In 93 adult women, the corresponding rate of increase for calcaneus lead content was 0.12 +/- 0.11 microgram [g mineral]-1 yr-1. Comparison with European values show that, in Canada, the rates of lead accumulation are greater than those found in N. Sweden and Finland, similar to those of S. Sweden and less than values measured in England.