The variability of lead in dusts within the homes of young children.

The variability of household dust lead concentration and loadings over the period of about a year has been examined in 10 homes. The overall uncertainty on a single sample is ± 65% for lead concentration and ± 81% for lead loading. Redecoration involving electric sanding and/or blow lamp preparation of painted surfaces is the major cause of variation in lead levels. The effect is short lived, levels returning to normal within 2 months of redecoration ending. There is evidence of a seasonal trend for dust loading and lead loading but not for lead concentration. The implications of these findings for blood lead - dust lead exposure studies are considered.