Abstract
Background
The independent effect of lead exposure and parental education on children’s neurocognition is well-documented. However, few studies have examined the combined effect of childhood lead exposure and parental education on adolescent neurocognition, especially in China.
Objective
Examine both the combined and interactive effect of childhood blood lead levels (BLLs) and parental education on early adolescent neurocognition.
Methods
417 children from a longitudinal cohort study in Jintan, China had BLLs measured at 3–5 years and 12 years, parental education levels assessed at 3–5 years, and neurocognitive outcomes tested at 12 years.
Results
BLLs at 3–5 years were inversely associated with adolescent IQ (β −0.55 95% CI: −0.97, −0.13) but not working memory (β −0.06 95% CI: −0.23, 0.11) and parental education was positively associated with adolescent IQ (β 0.68 95% CI: 0.19, 1.17) and working memory (β 0.24 95% CI: 0.04, 0.44). BLLs and parental education evidenced combined effects on neurocognition, where children with higher BLLs and lower fathers’ education had mean IQ scores 7.84 (95% CI: −13.15, −2.53) points lower than children with lower BLLs and higher fathers’ education. There were significant associations between parental education and working memory, however, not with BLLs. The interaction between mother and father high school education and BLLs was insignificant for effects on IQ and working memory.
Significance
Childhood lead exposure and parental education levels have a combined and long-term impact on IQ, evidence that may partially explain disparities in lead exposure associated outcomes and highlight those children at greatest risk for neurocognitive deficits.
Impact statement
Children continue to be exposed to low-levels of environmental lead in China and globally, warranting examination of the impact of such exposures. This paper demonstrates that even relatively low-level lead exposure in early childhood significantly influences adolescent neurocognitive functioning. Furthermore, co-existing social determinant of health-related variables, measured here as parental education, have a combined impact on neurocognition. These results highlight children at greater risk for neurocognitive deficits and demonstrate the need to examine the influence of lead exposure within the broader socio- ecological environment, as these factors work in tandem to influence longer-term neurocognitive outcomes.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 6 print issues and online access
$259.00 per year
only $43.17 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
Data are available from the corresponding author on reasonable request.
References
Vlasak T, Jordakieva G, Gnambs T, Augner C, Crevenna R, Winker R, et al. Blood lead levels and cognitive functioning: a meta-analysis. Sci Total Environ. 2019;668:678–84.
Institute for Health Metrics and Evaluation. GBD compare. Seattle, WA: University of Washington IHME; 2017. https://vizhub.healthdata.org/gbd-compare/.
World Health Organization. Lead poisoning and health: key facts. World Health Organization; 2021. https://www.who.int/en/news-room/fact-sheets/detail/lead-poisoning-and-health.
Li M-M, Gao Z-Y, Dong C-Y, Wu M-Q, Yan J, Cao J, et al. Contemporary blood lead levels of children aged 0–84 months in China: a national cross-sectional study. Environ Int. 2020;134:105288.
UNICEF, Pure Earth. The toxic truth: children’s exposure to lead pollution undermines a generation of future potential. 2020. https://www.unicef.org/media/73246/file/The-toxic-truth-children%E2%80%99s-exposure-to-lead-pollution-2020.pdf.
Muller C, Sampson RJ, Winter AS. Environmental inequality: the social causes and consequences of lead exposure. Annu Rev Sociol. 2018;44:263–82.
Lim S, Ha M, Hwang S-S, Son M, Kwon H-J. Disparities in children’s blood lead and mercury levels according to community and individual socioeconomic positions. Int J Environ Res Public Health. 2015;12:6232–48.
Liu J, Ai Y, McCauley L, Pinto-Martin J, Yan C, Shen X, et al. Blood lead levels and associated sociodemographic factors among preschool children in the South Eastern region of China. Paediatr Perinat Epidemiol. 2012;26:61–9.
World Health Organization. Childhood lead poisoning. Geneva, Switzerland: World Health Organization; 2010. https://www.who.int/ceh/publications/leadguidance.pdf.
Appleton AA, Holdsworth EA, Kubzansky LD. A systematic review of the interplay between social determinants and environmental exposures for early-life outcomes. Curr Environ Health Rep. 2016;3:287–301.
Chung KKH, Liu H, McBride C, Wong AMY, Lo JCM. How socioeconomic status, executive functioning and verbal interactions contribute to early academic achievement in Chinese children. Educ Psychol. 2017;37:402–20.
McEwen CA, McEwen BS. Social structure, adversity, toxic stress, and intergenerational poverty: an early childhood model. Annu Rev Sociol. 2017;43:445–72.
Ursache A, Noble KG. Neurocognitive development in socioeconomic context: multiple mechanisms and implications for measuring socioeconomic status. Psychophysiology. 2016;53:71–82.
Li Y, Qin J, Wei X, Li C, Wang J, Jiang M, et al. The risk factors of child lead poisoning in china: a meta-analysis. Int J Environ Res public health. 2016;13:296.
Martínez-Hernanz Á, González-Estecha M, Blanco M, Fuentes M, Ordóñez-Iriarte JM, Palazón-Bru I, et al. Blood lead in children and associations with trace elements and sociodemographic factors. J Trace Elem Med Biol. 2020;58:126424.
Noble KG, Houston SM, Brito NH, Bartsch H, Kan E, Kuperman JM, et al. Family income, parental education and brain structure in children and adolescents. Nat Neurosci. 2015;18:773–8.
Magzamen S, Amato MS, Imm P, Havlena JA, Coons MJ, Anderson HA, et al. Quantile regression in environmental health: early life lead exposure and end-of-grade exams. Environ Res. 2015;137:108–19.
Canfield RL, Henderson CR Jr, Cory-Slechta DA, Cox C, Jusko TA, Lanphear BP. Intellectual impairment in children with blood lead concentrations below 10 microg per deciliter. N Engl J Med. 2003;348:1517–26.
Arnold OM, Liu J. Blood lead levels ≤10 micrograms/deciliter and executive functioning across childhood development: a systematic review. Neurotoxicol Teratol. 2020;80:106888.
Diamond A. Executive functions. Annu Rev Psychol. 2013;64:135–68.
Wraw C, Deary IJ, Gale CR, Der G. Intelligence in youth and health at age 50. Intelligence. 2015;53:23–32.
Khurana A, Romer D, Betancourt LM, Brodsky NL, Giannetta JM, Hurt H. Stronger working memory reduces sexual risk taking in adolescents, even after controlling for parental influences. Child Dev. 2015;86:1125–41.
Liu J, Cao S, Chen Z, Raine A, Hanlon A, Ai Y, et al. Cohort profile update: the China Jintan Child Cohort study. Int J Epidemiol. 2015;44:1548–l.
World Health Organization. Brief guide to analytical methods for measuring lead in blood. World Health Organization- Inter-Organization Programme for the Sound Management of Chemicals; 2011. https://www.who.int/ipcs/assessment/public_health/lead_blood.pdf.
Yue MZ, ES G. School-age children Intelligence Scale, Wechsler the National Urban norm formulation. Practical Pediatrics. 1987;2:327–8.
Liu J, Lynn R. Chinese sex differences in intelligence: some new evidence. Personal Individ Differences. 2015;75:90–3.
Dang C-P, Braeken J, Ferrer E, Liu C. Unitary or non-unitary nature of working memory? Evidence from its relation to general fluid and crystallized intelligence. Intelligence 2012;40:499–508.
Zhou G, Ji X, Cui N, Cao S, Liu C, Liu J. Association between serum copper status and working memory in schoolchildren. Nutrients. 2015;7:7185–96.
Liu J, Portnoy J, Raine A, Gladieux M, McGarry P, Chen A. Blood lead levels mediate the relationship between social adversity and child externalizing behavior. Environ Res. 2021;204:112396.
Madhushanthi HJ, Wimalasekera SW, Goonewardena CSE, Amarasekara AATD, Lenora J. Socioeconomic status is a predictor of neurocognitive performance of early female adolescents. Int J Adolesc Med Health. 2020;32.
Benton D. Micronutrient status, cognition and behavioral problems in childhood. Eur J Nutr. 2008;47:38–50. Suppl 3.
Hegazy AA, Zaher MM, Abd El-Hafez MA, Morsy AA, Saleh RA. Relation between anemia and blood levels of lead, copper, zinc and iron among children. BMC Res Notes. 2010;3:133-.
Tong S, McMichael AJ, Baghurst PA. Interactions between environmental lead exposure and sociodemographic factors on cognitive development. Arch Environ Health. 2000;55:330–5.
Bellinger D, Leviton A, Waternaux C, Needleman H, Rabinowitz M. Low-level lead exposure, social class, and infant development. Neurotoxicol Teratol. 1988;10:497–503.
Marshall AT, Betts S, Kan EC, McConnell R, Lanphear BP, Sowell ER. Association of lead-exposure risk and family income with childhood brain outcomes. Nat Med. 2020;26:91–7.
Ris MD, Dietrich KN, Succop PA, Berger OG, Bornschein RL. Early exposure to lead and neuropsychological outcome in adolescence. J Int Neuropsychological Soc. 2004;10:261–70.
Tan TX, Zhou Y, Li G. Maternal education and Chinese second graders’ performance in language and literacy and math: testing the mediating effect of the home environment. Education 3-13. 2020;48:933–44.
Moodie S, Ialongo N, Lopez P, Rosado J, Garcia-Vargas G, Ronquillo D, et al. The conjoint influence of home enriched environment and lead exposure on children’s cognition and behaviour in a Mexican lead smelter community. Neurotoxicology. 2013;34:33–41.
Surkan PJ, Schnaas L, Wright RJ, Téllez-Rojo MM, Lamadrid-Figueroa H, Hu H, et al. Maternal self-esteem, exposure to lead, and child neurodevelopment. Neurotoxicology. 2008;29:278–85.
Marsiglio W. Paternal engagement activities with minor children. J Marriage Fam. 1991;53:973–86.
Li X. Fathers’ involvement in Chinese societies: Increasing presence, uneven progress. Child Dev Perspect. 2020;14:150–6.
Zhang X. The effects of parental education and family income on mother–child relationships, father–child relationships, and family environments in the People’s Republic of China. Fam Process. 2012;51:483–97.
Kong F, Chen Z, Xue S, Wang X, Liu J. Mother’s but not father’s education predicts general fluid intelligence in emerging adulthood: Behavioral and neuroanatomical evidence. Hum Brain Mapp. 2015;36:4582–91.
Fruh V, Rifas-Shiman SL, Amarasiriwardena C, Cardenas A, Bellinger DC, Wise LA, et al. Prenatal lead exposure and childhood executive function and behavioral difficulties in project viva. Neurotoxicology. 2019;75:105–15.
Vrijheid M, Casas M, Gascon M, Valvi D, Nieuwenhuijsen M. Environmental pollutants and child health-a review of recent concerns. Int J Hyg Environ Health. 2016;219:331–42.
Cohen S, Janicki-Deverts D, Chen E, Matthews KA. Childhood socioeconomic status and adult health. Ann N Y Acad Sci. 2010;1186:37–55.
Rocha A, Trujillo KA. Neurotoxicity of low-level lead exposure: History, mechanisms of action, and behavioral effects in humans and preclinical models. NeuroToxicology 2019;73:58–80.
Reuben A, Caspi A, Belsky DW, Broadbent J, Harrington H, Sugden K, et al. Association of childhood blood lead levels with cognitive function and socioeconomic status at age 38 years and with IQ change and socioeconomic mobility between childhood and adulthood. JAMA J Am Med Assoc. 2017;317:1244–51.
Larsen B, Luna B. Adolescence as a neurobiological critical period for the development of higher-order cognition. Neurosci Biobehav Rev. 2018;94:179–95.
Cecil KM, Brubaker CJ, Adler CM, Dietrich KN, Altaye M, Egelhoff JC, et al. Decreased brain volume in adults with childhood lead exposure. PLoS Med. 2008;5:e112.
Acknowledgements
The authors thankfully acknowledge the participating children and their families from Jintan City. We additionally thank Ryan Quinn for his assistance with the statistical analysis.
Funding
Funding was provided by the National Institute of Nursing Research (NIH/NINR, F31NR019527; R21 NR019047), the National Institute of Environment Health Sciences (NIH/NIEHS, R01-ES018858; K02-ES019878; K01-ES015877; T32ES007062), the National Institutes on Drug Abuse (NIH/NIDA, R21 DA046364), the National Institute of Child Health and Development (NIH/NICHD R01-HD087485), the University of Pennsylvania Center of Excellence in Environmental Toxicology (P30-ES013508), the Robert Wood Johnson Foundation Future of Nursing Scholars Program, and Sigma Theta Tau International Xi Chapter.
Author information
Authors and Affiliations
Contributions
OMH was responsible for the data analysis, results interpretation, and manuscript writing. JL was responsible for assisting with conceptual design, results interpretation, and substantive edits to the manuscript. Both JPM and PC were responsible for providing feedback on conceptual design, interpreting results, and manuscript revisions.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Ethics approval
Institutional Review Board approval for the study was obtained from the University of Pennsylvania and the ethical committee for research at Jintan Hospital, China.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Rights and permissions
About this article
Cite this article
Halabicky, O.M., Pinto-Martin, J.A., Compton, P. et al. Low level lead exposure in early childhood and parental education on adolescent IQ and working memory: a cohort study. J Expo Sci Environ Epidemiol 33, 168–176 (2023). https://doi.org/10.1038/s41370-022-00450-9
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41370-022-00450-9