Cognitive performance among cohorts of children exposed to a waste disposal site containing heavy metals in Chile

Abstract

Between 1984 and 1998, people living in Arica were involuntarily exposed to metal-containing waste stored in the urban area. The study aims to determine whether children who lived near the waste disposal site during early childhood experienced negative effects on their cognitive development. The cognitive performance was assessed using the Wechsler Intelligence Scale for Children. The exposure variable was defined by the year of birth in three categories: (1) Pre-remediation (born before 1999); (2) During-remediation (born between 1999 and 2003); and (3) Post-remediation (born after 2003). In the crude analysis, a difference of 10 points in the IQ average was observed between the group born in the pre- (81.9 points) and post-remediation period (91.1 points). The difference between both groups was five times higher as compared to children of similar age and socioeconomic status in other cities of Chile. This result could be related with a period of high potential for exposure to this contaminated site.

Keywords:

• Arsenic
• children
• heavy metals
• intellectual quotient

Acknowledgments

The authors would like to thank to the professionals of the Health Service and Regional Ministerial Secretariat (SEREMI) of Arica and Parinacota, Chile, who collaborated in the study. R. Arroyo from CEDETi for training the evaluators. To CEDETi for facilitating the use of WAIS-IV. To the team of interviewers consisted of N. Lafferte, C. Manriquez, Y. Rojas, A. Sepúlveda and evaluators G. Avendaño, C. Chamorro, L. Isla y M. Morales. We extend our appreciation to the families who participated in this research.