The effects of the exposure to neurotoxic elements on Italian schoolchildren behavior

Stefano Renzetti,Augusto Giorgino,Michele Conversano,Donatella Placidi,Stefano Guazzetti,Francesco Petrucci,Manuela Oppini,Anna Pino,Alessandro Alimonti,Giovanni Forte,Roberto G Lucchini,Silvia Zoni,Giuseppa Cagna,Chiara Fedrighi,Oreste Senofonte,Stefano Calza,Marco Peli,Costanza Majorani

doi:10.1038/s41598-021-88969-z

Abstract

Neurodevelopmental disorders are constantly increasing on a global scale. Some elements like heavy metals are known to be neurotoxic. In this cross-sectional study we assessed the neurobehavioral effect of the exposure to trace elements including lead, mercury, cadmium, manganese, arsenic and selenium and their interactions among 299 schoolchildren residing in the heavily polluted Taranto area in Italy. Whole blood, urine and hair were collected for metal analyses, while the Child Behavior Checklist and the Social Responsiveness Scale, administered to the main teacher and the mothers were considered to identify behavioral problems in children. Blood lead mainly influenced social problems, aggressive behavior, externalizing and total problems. Urinary arsenic showed an impact on anxiety and depression, somatic problems, attention problems and rule breaking behavior. A significant interaction between lead and arsenic was observed, with a synergistic effect of the two metals increasing the risk of attention problems, aggressive behavior, externalizing problems and total problems. Overall, we were able to test that higher blood lead, urinary arsenic concentrations and their interaction increase the risk of neurobehavioral problems. This is in line with the U.S. Environmental Protection Agency’s priority list of hazardous substances where arsenic and lead are ranked as first and second respectively.

Highlights

Neurodevelopmental disorders are constantly increasing on a global scale
Two of the neighborhoods closer to the industrial site (Tamburi and Paolo VI) were characterized by a lower percentage of high-level socio-economic status (SES) (1.3% and 0% respectively, Chi-squared p-value < 0.001), a higher frequency of passive smoking exposure (26.9% and 11.1% respectively, Chi-squared p-value < 0.001) and lower Intelligence Quotient (IQ) Children residing in Tamburi showed lower cognitive stimulation at home (median (1Q-3Q) Home Observation for Measurement of the Environment (HOME) total score equal to 5.0 (4.0, 6.0), Kruskall-Wallis p-value < 0.001), were slightly older and had a higher percentage of females than children living farther from the source
A poor agreement was found between parents and teachers evaluation (ICC ranging from 0.06 for anxiety problems to 0.36 for conduct problems) while the skewness and kurtosis highlighted a non-normal distribution of the lower level empirically-based syndrome and the DSM oriented scales

Summary

Introduction

Some elements like heavy metals are known to be neurotoxic In this cross-sectional study we assessed the neurobehavioral effect of the exposure to trace elements including lead, mercury, cadmium, manganese, arsenic and selenium and their interactions among 299 schoolchildren residing in the heavily polluted Taranto area in Italy. A significant interaction between lead and arsenic was observed, with a synergistic effect of the two metals increasing the risk of attention problems, aggressive behavior, externalizing problems and total problems. In this study we assessed the neurobehavioral effect of the exposure to some elements including Pb, Hg, Cd, Mn, As and Se among 6–11 years old children residing in the heavily polluted Taranto area in Italy considering the interactions among the elements that showed a significant association with the behavioral outcomes

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Conclusion