Prenatal Metal Exposures and Child Social Responsiveness Scale Scores in 2 Prospective Studies

Abstract

Background: Prenatal exposure to metals is hypothesized to be associated with child autism. We aim to investigate the joint and individual effects of prenatal exposure to urine metals including lead (Pb), mercury (Hg), manganese (Mn), and selenium (Se) on child Social Responsiveness Scale (SRS) scores. Methods: We used data from 2 cohorts enriched for likelihood of autism spectrum disorder (ASD): Early Autism Risk Longitudinal Investigation (EARLI) and the Markers of Autism Risk in Babies-Learning Early Signs (MARBLES) studies. Metal concentrations were measured in urine collected during pregnancy. We used Bayesian Kernel Machine Regression and linear regression models to investigate both joint and independent associations of metals with SRS Z-scores in each cohort. We adjusted for maternal age at delivery, interpregnancy interval, maternal education, child race/ethnicity, child sex, and/or study site. Results: The final analytic sample consisted of 251 mother-child pairs. When Pb, Hg, Se, and Mn were at their 75th percentiles, there was a 0.03 increase (95% credible interval [CI]: −0.11, 0.17) in EARLI and 0.07 decrease (95% CI: −0.29, 0.15) in MARBLES in childhood SRS Z-scores, compared to when all 4 metals were at their 50th percentiles. In both cohorts, increasing concentrations of Pb were associated with increasing values of SRS Z-scores, fixing the other metals to their 50th percentiles. However, all the 95% credible intervals contained the null. Conclusions: There were no clear monotonic associations between the overall prenatal metal mixture in pregnancy and childhood SRS Z-scores at 36 months. There were also no clear associations between individual metals within this mixture and childhood SRS Z-scores at 36 months. The overall effects of the metal mixture and the individual effects of each metal within this mixture on offspring SRS Z-scores might be heterogeneous across child sex and cohort. Further studies with larger sample sizes are warranted.

Association of Prenatal Dietary Toxicants and Inorganic Arsenic Exposure with Children’s Emotional and Behavioral Problems: ECLIPSES Study

“…Meanwhile, it also has been demonstrated that prenatal dietary exposure to dioxins during pregnancy is not associated ADHD symptoms [ 39 ]. In addition, all associations between prenatal metal levels (Pb, Hg, selenium, and manganese) and autism were either inconclusive or inconsistent [ 15 ]. In the current study, we found that among all prenatal dietary toxicants, high iAs was associated with elevated emotional and behavioral problems among four-year-old children, although higher dietary intake of iAs (4.16 μg/day) in this study was still relatively low compared to the tolerable daily intake as considered by the EFSA (0.3 μg/kg bw/day; given that the average weight in our population was 64.6 kg, this equated to 19.38 μg/day) [ 22 ].…”

“…For instance, some studies have presented that prenatal exposure to metals is associated with autism, emotional control, hyperactivity/inattention, and depression among children [ 11 , 12 , 13 , 14 ]. However, researchers have also found that the association between prenatal metal exposure and autism is null [ 15 ] and the associations of persistent organic pollutants (POPs) and heavy metals with behavioral problems are inconsistent [ 16 ].…”

Environmental Impact of the Heavy Metal Intoxication on Metabolic, Physiological and Nutritional Profiles in Children with Autism Spectrum Disorder in Morocco

“…Recent studies on ASD and metals underscore the significance of integrating exposure data with lifestyle and social factors. They utilize diverse biological samples like hair, nails, and teeth to track metal exposure history, with blood and urine serving for short-term exposure assessment (Yu et al, 2024). Initial epidemiological findings indicating the potential involvement of toxic heavy metals in ASD have validated the concept of 'heavy metal pollution' as a contributing factor (Ding et al, 2023).…”