title: Current uses of the EPA lead model to assess health risk and action levels for soil.
abstract: The EPA lead model predicts mean blood lead levels and risk of elevated blood lead levels in children based on lead uptake from multiple sources. In the latest model versions, environmental data from individual homes within a community can be used to predict the overall blood lead distribution and percent risk of exceeding a specific blood lead level (i.e. 10 μg dl(-1)). Recent criteria used by the EPA to evaluate this information include no more than 5% of houses with a greater than 5% lead risk, and a community weighted-average risk below 5%. Environmental (primarily soil) and blood lead data from a residential community near a smelter were used to illustrate recent uses of the model. Scheduled remediation in the community will remove soil for approximately 60% of the houses (i.e. those with lead levels > 1000 mg kg(-1)). After remediation, the model results indicate a relatively low community risk (0.5-1.9%), although the percentage of houses with lead risks above 5% ranged from 3 to as high as 13%, depending on the variation in blood lead and assuming the model's 7 μg dl(-1) increase in blood lead with each 1000 mg kg(-1) increase in soil lead level. A comparison of the limited blood lead data with soil lead levels below 1000 mg kg(-1), however, indicated no apparent relationship. Given these uncertainties, less invasive actions than additional soil removal (e.g. exposure intervention, monitoring conditions, and follow-up as necessary) may be appropriate under the new EPA guidance for lead in soil.
authors.affiliation: Kleinfelder, Inc., 3380 146th Place SE, Suite 110, 98007, Bellevue, WA, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Tsuji
authors.forename: K M
authors.initials: KM
authors.lastname: Serl