Lead concentrations in whole blood, serum, saliva and house dust in samples collected at two time points (12 months apart) in Santo Amaro, BA, Brazil.

UNLABELLED: Whole Blood Lead Level (BLL) is the main marker used to verify lead contamination. The present study explores how BLL is associated with lead concentrations in serum, saliva and house dust. Samples were collected twice from Santo Amaro, BA, Brazil, a region that was contaminated by a lead smelter in the past; a time interval of 12 months was allowed between the two collections. It is noteworthy that the following measures have recently been taken to diminish exposure of the population to lead: streets have been paved with asphalt, and educational campaigns have been launched to reduce exposure to contaminated dust.

RESULTS: Compared with the first time point, all the samples collected at the second time point contained lower lead concentration (p<0.05), which suggested that the adopted measures effectively reduced exposure of the population to lead present in contaminated soil and dust. Statistically significant correlations only existed between lead in blood collected in the first year and lead in blood collected in the second year (Spearman's r=0.55; p<0.0001; n=62), and lead in house dust collected in the first year and lead in house dust collected in the second year (Spearman's r=0.5; p<0.0001; n=59).

CONCLUSIONS: Results support the validity of lead determination in blood and in house dust to assess lead exposure over time. However, lead in blood and lead in dust did not correlate with lead in serum or lead in saliva.