Evidence of undue lead exposure in Cape Town before the advent of leaded petrol.

Lead concentrations were determined in the exhumed teeth of 28 people who lived in the Cape Town area before the combustion of leaded petrol (i.e. before 1922). The lead content of circumpulpal dentine was analysed by graphite-furnace atomic absorption spectrometry. The mean lead level in the dentine of primary teeth (N = 6) was 109 micrograms/g, while that in secondary teeth (N = 22) was 315 micrograms/g. The current lead levels in circumpulpal dentine of Cape Town residents are reported to be 74 micrograms/g and 16 micrograms/g for primary and secondary teeth respectively. It was found that lead pollution of the human body during the period 1812-1922 in the Cape Town area was substantially higher than at present. We conclude that the main reasons for this were the widespread use of lead piping and soldering of water tanks, which resulted in a higher incidence of lead poisoning than that attributable to leaded petrol.