Neurobehavioural measure* | Current PbB† | Current PbT | Peak PbT | AUC dose metric | ||||
---|---|---|---|---|---|---|---|---|
β‡ | p Value§ | β | p Value | β | p Value | β | p Value | |
*Selection from a battery of 16 tests. All tests scored so that a worsening of performance with increasing exposure is indicated by a negative sign. | ||||||||
†Dose metrics: current PbB, current blood lead concentration, at time of testing; current PbT, current tibial lead concentration, at time of testing; peak PbT, highest estimated tibial lead concentration, back-extrapolated using a one-compartment model and an average clearance half time of 27 years; AUC dose metric, area under the time-concentration curve for tibial lead. | ||||||||
‡Regression coefficient, adjusted for age, education and baseline score, and standardised so that all β represent change in score per standard deviation change in exposure/dose metric. | ||||||||
§p Value testing H_{0}: β = 0. Large coefficients relative to their standard errors indicated in bold italics. | ||||||||
Wechsler block design | 0.161 | 0.23 | −0.058 | 0.72 | −0.223 | 0.18 | −0.213 | 0.22 |
Wechsler symbol digit | −0.187 | 0.14 | −0.133 | 0.32 | −0.038 | 0.79 | 0.058 | 0.68 |
Symbol digit | −0.012 | 0.91 | −0.099 | 0.32 | −0.206 | 0.05 | −0.225 | 0.04 |
Serial digit learning | −0.160 | 0.23 | −0.020 | 0.90 | −0.104 | 0.52 | −0.149 | 0.37 |
Rey figure copy | −0.001 | 0.99 | −0.030 | 0.74 | −0.138 | 0.14 | −0.170 | 0.08 |
Rey figure recall | −0.174 | 0.05 | −0.077 | 0.39 | −0.174 | 0.07 | −0.196 | 0.04 |
Rey auditory learning, immediate recall | 0.049 | 0.77 | −0.255 | 0.15 | −0.571 | <0.001 | −0.671 | <0.001 |
Rey auditory learning, delayed recall | −0.055 | 0.32 | −0.128 | 0.02 | −0.149 | 0.01 | −0.134 | 0.02 |