The Fremantle lead study part 2

A 1993 study of blood lead levels (BLLs) in pre-schoolers living in Fremantle showed 25% had BLLs >or= 10 microg/dL. This study compares the 1993 BLLs with a sample of contemporary Fremantle pre-schoolers.

Pre-schoolers (0-5 years) living in the Fremantle area were recruited from hospital and community settings during 2005. As in the 1993 study, guardians completed a questionnaire concerning demographic, environmental and behavioural variables. BLLs were determined by the same method used in 1993. Statistical analysis compared the 1993 and 2005 samples according to demographic variables and dichotomised BLL. Multivariate linear regression was used to control for confounding variables, and linear regression was used to identify risk factors in the 2005 sample.

Community (40) and hospital (60) participants provided blood and completed questionnaires; none had BLLs >or=10 microg/dL. Compared with the 1993 sample, 2005 participants were younger, fewer were aboriginal, more had occupied their homes for over 6 months and more had a habit of putting soil in their mouths. After controlling for these variables, the geometric mean BLL in 2005 remained significantly lower than the 1993 value (1.83 and 6.82 microg/dL respectively). As in 1993, aboriginality, presence of participants during home renovation, occupancy of home less than 6 months and living <200 m from a main road were associated with higher mean BLLs.

The reassuring decline in the mean BLL between the1993 and 2005 samples is likely associated with the phasing out of leaded petrol. Future research should concentrate on monitoring groups at higher risk.