Int J Environ Res Public Health. 2014 Oct 17;11(10):10806-23. doi: 10.3390/ijerph111010806.

Evaluation of toxic metals and essential elements in children with learning disabilities from a rural area of southern Brazil.

do Nascimento SN1, Charão MF2, Moro AM3, Roehrs M4, Paniz C5, Baierle M6, Brucker N7, Gioda A8, Barbosa F Jr9, Bohrer D10, Ávila DS11, Garcia SC12.

• 1Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. sabrinascimento@hotmail.com.
• 2Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. marifeiffercharao@yahoo.com.br.
• 3Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. angelammoro@yahoo.com.br.
• 4Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. miguelroehrs@yahoo.com.br.
• 5Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. clovis.paniz@yahoo.com.br.
• 6Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. mariliabaierle@yahoo.com.br.
• 7Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. nataliafarma@hotmail.com.
• 8Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro, RJ 22451900, Brazil. agioda@hotmail.com.
• 9Laboratory of Toxicology and Essentiality of Metals, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP 14040903, Brazil. fbarbosa@fcfrp.usp.br.
• 10Chemistry Department, Federal University of Santa Maria, Santa Maria, RS 97105900, Brazil. bohrer.denise@gmail.com.
• 11Post-Graduate Program in Biochemistry, Federal University of Pampa, Uruguaiana, RS 97500970, Brazil. avilads1@gmail.com.
• 12Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. solange.garcia@ufrgs.br.

Abstract

Children's exposure to metals can result in adverse effects such as cognitive function impairments. This study aimed to evaluate some toxic metals and levels of essential trace elements in blood, hair, and drinking water in children from a rural area of Southern Brazil.

Cognitive ability and δ-aminolevulinate dehydratase (ALA-D) activity were evaluated. Oxidative stress was evaluated as a main mechanism of metal toxicity, through the quantification of malondialdehyde (MDA) levels.

This study included 20 children from a rural area and 20 children from an urban area. Our findings demonstrated increase in blood lead (Pb) levels (BLLs). Also, increased levels of nickel (Ni) in blood and increase of aluminum (Al) levels in hair and drinking water in rural children were found.

Deficiency in selenium (Se) levels was observed in rural children as well.

Rural children with visual-motor immaturity presented Pb levels in hair significantly increased in relation to rural children without visual-motor immaturity (p < 0.05). Negative correlations between BLLs and ALA-D activity and positive correlations between BLLs and ALA-RE activity were observed.

MDA was significantly higher in rural compared to urban children (p < 0.05).

Our findings suggest that rural children were co-exposed to toxic metals, especially Al, Pb and Ni. Moreover, a slight deficiency of Se was observed. Low performance on cognitive ability tests and ALA-D inhibition can be related to metal exposure in rural children. Oxidative stress was suggested as a main toxicological mechanism involved in metal exposure.

PMID:  25329533