Author(s): Roels H, Konings J, Green S, Bradley D, Chettle D,
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Abstract The concentration of lead in tibia (Pb-T) was measured in vivo by a 109Cd K-shell X-ray fluorescence technique in 123 workers from a primary lead smelter (age: mean, 45 years; range, 30-61; duration of employment: mean, 20 years; range, 7-45). Their cumulative blood lead index (CBLI) was also calculated on the basis of the blood lead (Pb-B) records available from the company's medical files. Geometric mean for Pb-T was 49 micrograms Pb/g bone mineral (range, 15-167). The company's health surveillance programs, implemented since 1945, resulted in Pb-B values which rarely exceeded 70 micrograms Pb/dl whole blood. Pb-B at the time of Pb-T measurement averaged 31 micrograms Pb/dl (range, 6-62) and the geometric mean for CBLI amounted to 803 micrograms Pb/dl x year (range, 220-2130). Despite various assumptions and uncertainties inherent in the assessment of the cumulative lead dose through Pb-T measurement or CBLI calculation, the relation between both variables in the present lead smelter populations is very strong (rpearson = 0.80, P < 0.0001; age explained at the most 9.5\% of the variance). The slope of the regression equation of log Pb-T vs log CBLI showed that a doubling of CBLI also corresponds to doubling of Pb-T. It may be concluded that a sound calculation of CBLI represents a valid surrogate for estimating the life time integrated dose of lead as assessed by the measurement of cortical bone lead (e.g., in tibia).
This article was published in Environ Res
and referenced in Journal of Biometrics & Biostatistics