TY - JOUR
T1 - Inverse association of intellectual function with very low blood lead but not with manganese exposure in Italian adolescents
AU - Lucchini, Roberto G.
AU - Zoni, Silvia
AU - Guazzetti, Stefano
AU - Bontempi, Elza
AU - Micheletti, Serena
AU - Broberg, Karin
AU - Parrinello, Giovanni
AU - Smith, Donald R.
N1 - Funding Information:
This study was supported by funding from the European Union through its Sixth Framework Programme for RTD (contract no FOOD-CT-2006- 016253 ). It reflects only the authors’ views, and the European Commission is not liable for any use that may be made of the information contained therein. The project was supported also by Award Number R01ES019222 from the National Institute Of Environmental Health Sciences . The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute Of Environmental Health Sciences or the National Institutes of Health. We thank Karin Paulsson for help with the genetic analyses and Phil Landrigan for reviewing the manuscript.
PY - 2012/10
Y1 - 2012/10
N2 - 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 μg/dL (median 1.5, range 0.44-10.2), mean Blood Manganese (BMn) was 11.1 μg/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 μg/dL, with a lower 95% confidence limit (BMLL01) of 0.11 μg/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.
AB - 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 μg/dL (median 1.5, range 0.44-10.2), mean Blood Manganese (BMn) was 11.1 μg/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 μg/dL, with a lower 95% confidence limit (BMLL01) of 0.11 μg/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.
KW - Children
KW - Cognitive functions
KW - Lead
KW - Manganese
UR - https://www.scopus.com/pages/publications/84866014309
U2 - 10.1016/j.envres.2012.08.003
DO - 10.1016/j.envres.2012.08.003
M3 - Article
C2 - 22925625
AN - SCOPUS:84866014309
SN - 0013-9351
VL - 118
SP - 65
EP - 71
JO - Environmental Research
JF - Environmental Research
ER -