Bridging the gap: Early childhood lead exposure and exceptionality designations for students

Environmental exposures may represent an important explanator of the persistent achievement gap in the US. We explore whether early childhood lead exposure is associated with being designated exceptional. Data from the NC Childhood Lead Poisoning Prevention Program surveillance registry were linked at the individual child level to data from the NC Education Research Data Center. We constructed four distinct student groups based on exceptionality status: 1) no exceptional status designated (ND); 2) designated exceptional due to placement in advanced and intellectually gifted programs (AIG); 3) designated exceptional due to learning or behavioral classifications (LBED); and 4) designated exceptional for other reasons (EDO). Bivariate analyses indicate that blood lead levels and EOG scores differ by exceptionality, as well as by race and enrollment in free/reduced lunch. Multivariate logistic regression revealed clear patterns. At each blood lead level, as low as 2 ug/dL, blood lead reduces the likelihood that children will be designated AIG. In contrast, blood lead levels as low as 4 ug/dL significantly increase the likelihood that a child will be designated LBED. Importantly, in models without lead exposure, non-Hispanic black (NHB) race is highly significant in predicting LBED designation. However, once lead is added to the model, NHB race does not have an impact on the likelihood that a child will be designated LBED. Blood lead levels as low as 8 ug/dL significantly increase the likelihood that a child will be designated EDO. These results provide important evidence that early childhood lead exposure contributes to the achievement gap.