Table 4.

Linear regression models of logarithm₁₀ Pb in blood concentrations as dependent variables of logarithm₁₀ Pb in soil concentrations, in the neighborhoods of the elementary schools were children lived at 0, 6, 12 and 60 months of follow-up in Torreon Coahuila.

Follow-up	n*	Coefficient (CI 95%)	Beta	P > | t |
0	196	0.095 (0.0494 - 0.1407)	0.283	0.000
6	196	0.074 (0.0279 - 0.1192)	0.222	0.002
12	196	0.130 (0.8336 - 0.1765)	0.367	0.000
60	196	- 0.009 (-0.6068 - 0.0433)	- 0.024	0.743

*.- There were 196 children who lived in the vicinity of the elementary school from where the soil samples were gathered.

CI. Confidence interval of regression coefficient at 95%.