title: Evaluation of toxic metals and essential elements in children with learning disabilities from a rural area of southern Brazil.
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.
authors.affiliation: Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. sabrinascimento@hotmail.com.
authors.forename: Sabrina Nunes
authors.initials: SN
authors.lastname: do Nascimento
authors.affiliation: Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. marifeiffercharao@yahoo.com.br.
authors.forename: Mariele Feiffer
authors.initials: MF
authors.lastname: Charão
authors.affiliation: Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. angelammoro@yahoo.com.br.
authors.forename: Angela Maria
authors.initials: AM
authors.lastname: Moro
authors.affiliation: Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. miguelroehrs@yahoo.com.br.
authors.forename: Miguel
authors.initials: M
authors.lastname: Roehrs
authors.affiliation: Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. clovis.paniz@yahoo.com.br.
authors.forename: Clovis
authors.initials: C
authors.lastname: Paniz
authors.affiliation: Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. mariliabaierle@yahoo.com.br.
authors.forename: Marília
authors.initials: M
authors.lastname: Baierle
authors.affiliation: Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. nataliafarma@hotmail.com.
authors.forename: Natália
authors.initials: N
authors.lastname: Brucker
authors.affiliation: Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro, RJ 22451900, Brazil. agioda@hotmail.com.
authors.forename: Adriana
authors.initials: A
authors.lastname: Gioda
authors.affiliation: Laboratory 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.
authors.forename: Fernando
authors.initials: F
authors.lastname: Barbosa
authors.affiliation: Chemistry Department, Federal University of Santa Maria, Santa Maria, RS 97105900, Brazil. bohrer.denise@gmail.com.
authors.forename: Denise
authors.initials: D
authors.lastname: Bohrer
authors.affiliation: Post-Graduate Program in Biochemistry, Federal University of Pampa, Uruguaiana, RS 97500970, Brazil. avilads1@gmail.com.
authors.forename: Daiana Silva
authors.initials: DS
authors.lastname: Ávila
authors.affiliation: Laboratory of Toxicology (LATOX), Department of Analysis, Federal University of Rio Grande do Sul, Porto Alegre, RS 90610000, Brazil. solange.garcia@ufrgs.br.
authors.forename: Solange Cristina
authors.initials: SC
authors.lastname: Garcia
mesh_terms: D000293:Adolescent; D000535:Aluminum / Q000032:analysis*; D001938:Brazil; D002648:Child; D060766:Drinking Water / Q000032:analysis; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000032:analysis / Q000097:blood*; D005260:Female; D006197:Hair / Q000737:chemistry*; D006801:Humans; D007854:Lead / Q000097:blood*; D007859:Learning Disabilities / Q000097:blood / Q000453:epidemiology*; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D009532:Nickel / Q000097:blood*; D000623:Porphobilinogen Synthase / Q000097:blood; D012424:Rural Population; D012643:Selenium / Q000172:deficiency*; D014131:Trace Elements / Q000097:blood*
chemical_list: D060766:Drinking Water; D004785:Environmental Pollutants; D014131:Trace Elements; D007854:Lead; D008315:Malondialdehyde; D009532:Nickel; D000535:Aluminum; D000623:Porphobilinogen Synthase; D012643:Selenium