A simple lead dust fall method predicts children's blood lead level: New evidence from Australia
We have measured dust fall accumulation in petri dishes (PDD) collected 6 monthly from inside residences in Sydney urban area, New South Wales, Australia as part of a 5-year longitudinal study to determine environmental associations, including soil. with blood lead (PbB) levels. The Pb loading in the dishes (n = 706) had geometric means (GM) of 24 μg/m2/30d, a median value of 22 μg/m2/30d with a range from 0.2 to 11,390 μg/m2/30d. Observed geometric mean PbB was 2.4 μg/dL at ages 2–3 years. Regression analyses showed a statistically significant relationship between predicted PbB and PDD. The predicted PbB values from dust in our study are consistent with similar analyses from the US in which floor dust was collected by wipes. Predicted PbB values from PDD indicate that an increase in PDD of about 100 μg/m2/30d would increase PbB by about 1.5 μg/dL or a doubling PbB at the low levels currently observed in many countries. Predicted PbB values from soil indicate that a change from 0 to 1000 mg Pb/kg results in an increase of 1.7 μg/dL in PbB, consistent with earlier investigations. Blood Pb levels can be predicted from dust fall accumulation (and soil) in cases where blood sampling is not always possible, especially in young children. Petri dish loading data could provide an alternative or complementary “action level” at about 100 μg Pb/m2/30 days, similar to the suggested level of about 110 μg Pb/m2 for surface wipes, for use in monitoring activities such as housing rehabilitation, demolition or soil resuspension.