Blood lead levels and growth status among African-American and Hispanic children in Dallas, Texas--1980 and 2002: Dallas Lead Project II.

OBJECTIVE

The purpose of this investigation is to analyze childhood blood lead levels and growth status (ages 2-12) in Dallas, Texas lead smelter communities in the 1980s and 2002, where smelters operated from 1936 to 1990.

METHODS AND MATERIALS

A sample of convenience study design was used in two cohorts (n=360): 1980-1989 (n=191) and 2002 (n=169). Multivariate analysis of variance and covariance and tandem multiple regressions were used to evaluate the association between stature and blood lead level in two time periods.

RESULTS

In 2002 average child blood lead level (1.6 microg/dL+/-0.2 SE) was significantly (p<0.001) lower compared to the 1980 cohort mean level (23.6 microg/dL+/-1.3 SE). Average height and weight in 2002 were 4.5 cm and 4.0 kg greater, respectively, than in 1980. Lowered blood lead level was associated with 3.9 cm, 3.5 kg and 1.1 units greater height, weight and body mass index (BMI), respectively. Cohort effect was associated with greater height (0.6 cm), weight (0.5 kg) and BMI (0.1).

CONCLUSION

This investigation reports on child growth in a community before and after the transition from high to low blood lead levels over several decades. Using child growth as a proxy, health status of Dallas's lead smelter communities increased markedly over the past two decades, primarily because of lower blood lead levels, while the poverty rate was only marginally lower.