Breastfeeding, Exposure to Organochlorine Compounds, and Neurodevelopment in
Infants
Núria Ribas-Fitó, MD*, Esther Cardo,
MD, PhD*, Maria Sala, MD, PhD*,
M. Eulàlia de Muga, MD*, Carlos Mazón, MD,
Antoni Verdú, MD, Manolis Kogevinas, MD, PhD*,
Joan O. Grimalt, PhD|| and Jordi Sunyer, MD, PhD*
* Environmental and Respiratory Research Unit, Institut Municipal
dInvestigació Mèdica, Barcelona, Spain
Primary Health Care Center of Flix, Tarragona, Spain
Department of Pediatrics, Hospital de Móra dEbre, Tarragona, Spain || Department of Environmental Chemistry, CID-CSIC, Barcelona, Spain.
Objective. Exposure to organochlorine compounds (OCs) occursboth 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 Spainwere
among the highest ever reported. We studied the associationbetween
exposure to OCs and breastfeeding on neurodevelopmentin the
1-year-old infants of this population.
Methods. A birth cohort including 92 mother-infant pairs wasrecruited between 1997 and 1999 in 5 neighboring villages (84%
of possible recruits). The mental and psychomotor developmentof each
infant was assessed at 13 months using the Bayley andthe Griffiths
Scales of Infant Development. OCs were measuredin cord serum.
Results. Dichlorodiphenyl dichloroethylene (p,p'DDE) cord serumlevels were negatively associated with both mental and psychomotordevelopment. For each doubling of a dose of p,p'DDE, we founda
resultant decrease of 3.50 points (standard error: 1.39) onthe
mental scale and 4.01 points (standard error: 1.37) on the
psychomotor scale. Exposure to polychlorinated biphenyls wasonly
marginally associated with psychomotor development. Prenatalexposure
to HCB had no effect on child neurodevelopment. Long-term
breastfeeding was associated with better performance on boththe
mental and motor scales. Short-term breastfed infants withhigher
p,p'DDE levels in cord serum were associated with thelowest scores
on both the mental and the psychomotor scales.
Conclusions. Prenatal exposure to p,p'DDE was associated witha 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.
Key Words: hexachlorobenzene dichlorodiphenyl
dichloroethylene polychlorinated biphenyls breastfeeding neurodevelopment
PCB, polychlorinated biphenyl OC, organochlorine compound HCB,
hexachlorobenzene MDI, Mental, Development Index PDI, Psychomotor
Developmental Index p,p'DDE, dichlorodiphenyl dichloroethylene SE, standard
error
Received for publication Jun 13, 2002; accepted Dec 20, 2002.
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