Breastfeeding, exposure to organochlorine compounds, and neurodevelopment in infants.
OBJECTIVE
Exposure to organochlorine compounds (OCs) occurs both in utero and through breastfeeding. Levels of hexachlorobenzene (HCB) found in the cord serum of newborns from a population located in the vicinity of an electrochemical factory in Spain were among the highest ever reported. We studied the association between exposure to OCs and breastfeeding on neurodevelopment in the 1-year-old infants of this population.


METHODS
A birth cohort including 92 mother-infant pairs was recruited between 1997 and 1999 in 5 neighboring villages (84% of possible recruits). The mental and psychomotor development of each infant was assessed at 13 months using the Bayley and the Griffiths Scales of Infant Development. OCs were measured in cord serum.


RESULTS
Dichlorodiphenyl dichloroethylene (p,p'DDE) cord serum levels were negatively associated with both mental and psychomotor development. For each doubling of a dose of p,p'DDE, we found a resultant decrease of 3.50 points (standard error: 1.39) on the mental scale and 4.01 points (standard error: 1.37) on the psychomotor scale. Exposure to polychlorinated biphenyls was only marginally associated with psychomotor development. Prenatal exposure to HCB had no effect on child neurodevelopment. Long-term breastfeeding was associated with better performance on both the mental and motor scales. Short-term breastfed infants with higher p,p'DDE levels in cord serum were associated with the lowest scores on both the mental and the psychomotor scales.


CONCLUSIONS
Prenatal exposure to p,p'DDE was associated with a delay in mental and psychomotor development at 13 months. No association was found for exposure to HCB. Long-term breastfeeding was found to be beneficial to neurodevelopment, potentially counterbalancing the impact of exposure to these chemicals through breast milk.
Environmental and Respiratory Research Unit, Institut Municipal d'Investigació Mèdica, Barcelona, Spain.
Núria
N
Ribas-Fitó
Esther
E
Cardo
Maria
M
Sala
M
M
Eulàlia de Muga
Carlos
C
Mazón
Antoni
A
Verdú
Manolis
M
Kogevinas
Joan O
JO
Grimalt
Jordi
J
Sunyer
D001942:Breast Feeding / Q000706:statistics & numerical data; D015331:Cohort Studies; D002658:Developmental Disabilities / Q000139:chemically induced* / Q000453:epidemiology; D003633:Dichlorodiphenyl Dichloroethylene / Q000009:adverse effects / Q000097:blood / Q000378:metabolism; D005314:Embryonic and Fetal Development / Q000187:drug effects; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007306:Insecticides / Q000009:adverse effects* / Q000097:blood / Q000378:metabolism; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D008431:Maternal-Fetal Exchange / Q000502:physiology; D001523:Mental Disorders / Q000139:chemically induced / Q000453:epidemiology; D008895:Milk, Human / Q000737:chemistry / Q000378:metabolism; D011247:Pregnancy; D011596:Psychomotor Disorders / Q000139:chemically induced / Q000453:epidemiology; D012044:Regression Analysis
D007306:Insecticides; D003633:Dichlorodiphenyl Dichloroethylene