An international pooled analysis for obtaining a benchmark dose for environmental lead exposure in children

TY - JOUR

T1 - An international pooled analysis for obtaining a benchmark dose for environmental lead exposure in children

AU - Budtz-Jørgensen, Esben

AU - Bellinger, David

AU - Lanphear, Bruce

AU - Grandjean, Philippe

N1 - © 2012 Society for Risk Analysis.

PY - 2013/1/1

Y1 - 2013/1/1

N2 - Lead is a recognized neurotoxicant, but estimating effects at the lowest measurable levels is difficult. An international pooled analysis of data from seven cohort studies reported an inverse and supra-linear relationship between blood lead concentrations and IQ scores in children. The lack of a clear threshold presents a challenge to the identification of an acceptable level of exposure. The benchmark dose (BMD) is defined as the dose that leads to a specific known loss. As an alternative to elusive thresholds, the BMD is being used increasingly by regulatory authorities. Using the pooled data, this article presents BMD results and applies different statistical techniques in the analysis of multistudy data. The calculations showed only a limited variation between studies in the steepness of the dose-response functions. BMD results were quite robust to modeling assumptions with the best fitting models yielding lower confidence limits (BMDLs) of about 0.1-1.0 μ g/dL for the dose leading to a loss of one IQ point. We conclude that current allowable blood lead concentrations need to be lowered and further prevention efforts are needed to protect children from lead toxicity.

AB - Lead is a recognized neurotoxicant, but estimating effects at the lowest measurable levels is difficult. An international pooled analysis of data from seven cohort studies reported an inverse and supra-linear relationship between blood lead concentrations and IQ scores in children. The lack of a clear threshold presents a challenge to the identification of an acceptable level of exposure. The benchmark dose (BMD) is defined as the dose that leads to a specific known loss. As an alternative to elusive thresholds, the BMD is being used increasingly by regulatory authorities. Using the pooled data, this article presents BMD results and applies different statistical techniques in the analysis of multistudy data. The calculations showed only a limited variation between studies in the steepness of the dose-response functions. BMD results were quite robust to modeling assumptions with the best fitting models yielding lower confidence limits (BMDLs) of about 0.1-1.0 μ g/dL for the dose leading to a loss of one IQ point. We conclude that current allowable blood lead concentrations need to be lowered and further prevention efforts are needed to protect children from lead toxicity.

KW - Child

KW - Dose-Response Relationship, Drug

KW - Environmental Pollutants

KW - Humans

KW - Lead

U2 - 10.1111/j.1539-6924.2012.01882.x

DO - 10.1111/j.1539-6924.2012.01882.x

M3 - Journal article

C2 - 22924487

SN - 0272-4332

VL - 33

SP - 450

EP - 461

JO - Risk Analysis

JF - Risk Analysis

IS - 3

ER -