Blood Lead Levels and Learning Disabilities: A Cross-Sectional Study of the 2003-2004 National Health and Nutrition Examination Survey (NHANES).

Janet Kern,Mark Geier,David Geier

doi:10.3390/ijerph14101202

Janet Kern, Mark Geier + Show 1 more

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https://doi.org/10.3390/ijerph14101202

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Abstract

Difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning or mathematical abilities are present among persons diagnosed with learning disabilities (LDs). Previous studies suggest a significant relationship between lead (Pb) exposure and LDs. This study evaluated the potential dose-response relationship between blood Pb levels and the risk of LDs. This cross-sectional study examined 1411 children (32,788,743 weighted-persons) between 6 and 15 years old from the 2003–2004 National Health and Nutrition Examination Survey (NHANES) by analyzing demographics, health related-questions, and laboratory tests using survey logistic and frequency modeling in SAS. On a µg Pb/dL basis, a significant dose-dependent relationship between increasing blood Pb levels and increasing risk of LDs was observed (odds ratio (OR) = 1.21, 95% confidence interval (CI) = 1.03–1.43). The relationship remained significant when examining covariates such as gender and race (OR = 1.19, 95% CI = 1.00–1.40). By contrast, no dose-dependence was observed between increasing blood Pb levels and the risk of hay fever in the last year (OR = 0.77, 95% CI = 0.56–1.056), a non-plausibly biologically related outcome of blood Pb levels. Persons in the 50th–75th (12.80%) and 75th–100th (17.14%) percentiles of blood Pb were significantly more likely to have LDs than persons in the 0–50th percentile of blood Pb (8.78%). An estimated 1 million persons born in the US from 1989 to 1998 developed LDs from elevated blood Pb levels. Overall, this study revealed a significant dose-dependent association between increasing childhood blood Pb levels and the risk of a LD diagnosis, but it was not possible to ascribe a direct cause-effect relationship between blood Pb exposure and LD diagnosis. Childhood Pb exposure should be considered when evaluating children with LDs, and continuing efforts should be made to reduce Pb exposure.

Highlights

IntroductionAmong individuals diagnosed with learning disabilities (LDs), there are difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, or mathematical abilities
Among individuals diagnosed with learning disabilities (LDs), there are difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, or mathematical abilities.According to the United States (US) Agency for Toxic Substances and Disease Registry (ATSDR), low doses of lead (Pb) can cause a broad range of functional problems, including many different types of LDs [1]
The current study examined the 2003–2004 National Health and Nutrition Examination Survey (NHANES) data to evaluate the potential relationship between blood Pb levels and the risk of LDs

Summary

Introduction

Among individuals diagnosed with learning disabilities (LDs), there are difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning, or mathematical abilities. According to the United States (US) Agency for Toxic Substances and Disease Registry (ATSDR), low doses of lead (Pb) can cause a broad range of functional problems, including many different types of LDs [1]. The ATSDR described that many children diagnosed with LDs as a consequence of Pb exposure perform poorly in school [1]. Previous studies suggest a significant relationship between Pb exposure and LDs [1,2]. Kaiser et al [3] used extant datasets from the Florida Department of Health, Childhood Lead Poisoning Prevention Program and the Florida Department of Education to compare children who were tested for Pb poisoning to children not tested for Pb poisoning.

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