Prenatal exposure to mirex impairs neurodevelopment at age of 4 years.
BACKGROUND
Some studies have suggested that certain organochlorine (OC) compounds may impair neurodevelopment in animals and humans. The objective of this study was to investigate the association between prenatal exposure to an OC pesticide, mirex, and cognitive development in children at age of 4 years.


METHODS
A population-based birth cohort in Granada (Spain) recruited between 2000 and 2002 was studied between 2005 and 2006, when the children were 4 years old. Complete data for analyses, including mirex determination in placentas, were gathered on a random sample of 104 children. A standardized version of the McCarthy Scales of Children's Abilities (MSCA) was used to assess children's motor and cognitive abilities. Multivariate analyses were performed to evaluate the relation between MSCA scores and prenatal exposure to mirex, adjusting for potential confounders.


RESULTS
The presence of mirex in placenta was inversely associated with cognitive development at 4 years of age: children with prenatal exposure to mirex (>or=limit of quantification: 26%; median: 1.4 ng/g placenta) showed a decrease of 5.15 points in working memory and of 7.33 points in the quantitative area with respect to children of the same age not prenatally exposed to mirex.


CONCLUSIONS
The deficit found in intellectual function during early childhood suggests that prenatal exposure to mirex may have a significant impact on school performance.
Puertas
Raquel
R
Department of Personality, Evaluation and Psychological Treatment, School of Psychology, University of Granada, Spain.
Lopez-Espinosa
Maria-Jose
MJ
Cruz
Francisco
F
Ramos
Rosa
R
Freire
Carmen
C
Pérez-García
Miguel
M
Abril
Ana
A
Julvez
Jordi
J
Salvatierra
Maite
M
Campoy
Cristina
C
Olea
Nicolas
N
D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D015331:Cohort Studies; D002658:Developmental Disabilities / Q000209:etiology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D008917:Mirex / Q000009:adverse effects* / Q000378:metabolism; D009483:Neuropsychological Tests; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology; D012044:Regression Analysis; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
D008917:Mirex