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Inverse association of intellectual function with very low blood lead but not with manganese exposure in Italian adolescents

Lucchini, Roberto G.; Zoni, Silvia; Guazzetti, Stefano; Bontempi, Elza; Micheletti, Serena; Broberg Palmgren, Karin LU ; Parrinello, Giovanni and Smith, Donald R. (2012) In Environmental Research 118. p.65-71
Abstract
Background: Pediatric lead (Pb) exposure impacts cognitive function and behavior and co-exposure to manganese (Mn) may enhance neurotoxicity. Objectives: To assess cognitive and behavioral function in adolescents with environmental exposure to Pb and Mn. Methods: In this cross sectional study, cognitive function and behavior were examined in healthy adolescents with environmental exposure to metals. The Wechsler Intelligence Scale for Children (WISC) and the Conners-Wells' Adolescent Self-Report Scale Long Form (CASS:L) were used to assess cognitive and behavioral function, respectively. ALAD polymorphisms rs1800435 and rs1139488 were measured as potential modifiers. Results: We examined 299 adolescents (49.2% females) aged 11-14 years.... (More)
Background: Pediatric lead (Pb) exposure impacts cognitive function and behavior and co-exposure to manganese (Mn) may enhance neurotoxicity. Objectives: To assess cognitive and behavioral function in adolescents with environmental exposure to Pb and Mn. Methods: In this cross sectional study, cognitive function and behavior were examined in healthy adolescents with environmental exposure to metals. The Wechsler Intelligence Scale for Children (WISC) and the Conners-Wells' Adolescent Self-Report Scale Long Form (CASS:L) were used to assess cognitive and behavioral function, respectively. ALAD polymorphisms rs1800435 and rs1139488 were measured as potential modifiers. Results: We examined 299 adolescents (49.2% females) aged 11-14 years. Blood lead (BPb) averaged 1.71 mu g/dL (median 1.5, range 0.44-10.2), mean Blood Manganese (BMn) was 11.1 mu g/dL (median 10.9, range 4.00-24.1). Average total IQ was 106.3 (verbal IQ= 102, performance IQ= 109.3). According to a multiple regression model considering the effect of other covariates, a reduction of about 2.4 IQ points resulted from a two-fold increase of BPb. The Benchmark Level of BPb associated with a loss of 1 IQ-point (BML01) was 0.19 mu g/dL, with a lower 95% confidence limit (BMLL01) of 0.11 mu g/dL. A very weak correlation resulted between BPb and the ADHD-like behavior (Kendall's tau rank correlation=0.074, p=0.07). No influence of ALAD genotype was observed on any outcome. Manganese was not associated with cognitive and behavioral outcomes, nor was there any interaction with lead. Conclusions: These findings demonstrate that very low level of lead exposure has a significant negative impact on cognitive function in adolescent children. Being an essential micro-nutrient, manganese may not cause cognitive effects at these low exposure levels. (c) 2012 Elsevier Inc. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cognitive functions, Lead, Manganese, Children
in
Environmental Research
volume
118
pages
65 - 71
publisher
Elsevier
external identifiers
  • wos:000309303100009
  • scopus:84866014309
ISSN
1096-0953
DOI
10.1016/j.envres.2012.08.003
language
English
LU publication?
yes
id
3588b61c-580a-46d6-95cb-3694cdfa500f (old id 3187474)
date added to LUP
2012-12-06 13:03:22
date last changed
2017-11-12 03:07:46
@article{3588b61c-580a-46d6-95cb-3694cdfa500f,
  abstract     = {Background: Pediatric lead (Pb) exposure impacts cognitive function and behavior and co-exposure to manganese (Mn) may enhance neurotoxicity. Objectives: To assess cognitive and behavioral function in adolescents with environmental exposure to Pb and Mn. Methods: In this cross sectional study, cognitive function and behavior were examined in healthy adolescents with environmental exposure to metals. The Wechsler Intelligence Scale for Children (WISC) and the Conners-Wells' Adolescent Self-Report Scale Long Form (CASS:L) were used to assess cognitive and behavioral function, respectively. ALAD polymorphisms rs1800435 and rs1139488 were measured as potential modifiers. Results: We examined 299 adolescents (49.2% females) aged 11-14 years. Blood lead (BPb) averaged 1.71 mu g/dL (median 1.5, range 0.44-10.2), mean Blood Manganese (BMn) was 11.1 mu g/dL (median 10.9, range 4.00-24.1). Average total IQ was 106.3 (verbal IQ= 102, performance IQ= 109.3). According to a multiple regression model considering the effect of other covariates, a reduction of about 2.4 IQ points resulted from a two-fold increase of BPb. The Benchmark Level of BPb associated with a loss of 1 IQ-point (BML01) was 0.19 mu g/dL, with a lower 95% confidence limit (BMLL01) of 0.11 mu g/dL. A very weak correlation resulted between BPb and the ADHD-like behavior (Kendall's tau rank correlation=0.074, p=0.07). No influence of ALAD genotype was observed on any outcome. Manganese was not associated with cognitive and behavioral outcomes, nor was there any interaction with lead. Conclusions: These findings demonstrate that very low level of lead exposure has a significant negative impact on cognitive function in adolescent children. Being an essential micro-nutrient, manganese may not cause cognitive effects at these low exposure levels. (c) 2012 Elsevier Inc. All rights reserved.},
  author       = {Lucchini, Roberto G. and Zoni, Silvia and Guazzetti, Stefano and Bontempi, Elza and Micheletti, Serena and Broberg Palmgren, Karin and Parrinello, Giovanni and Smith, Donald R.},
  issn         = {1096-0953},
  keyword      = {Cognitive functions,Lead,Manganese,Children},
  language     = {eng},
  pages        = {65--71},
  publisher    = {Elsevier},
  series       = {Environmental Research},
  title        = {Inverse association of intellectual function with very low blood lead but not with manganese exposure in Italian adolescents},
  url          = {http://dx.doi.org/10.1016/j.envres.2012.08.003},
  volume       = {118},
  year         = {2012},
}