Iron deficiency associated with higher blood lead in children living in contaminated environments.
Environ Health Perspect
; 109(10): 1079-84, 2001 Oct.
Article
de En
| MEDLINE
| ID: mdl-11675273
ABSTRACT
The evidence that iron deficiency increases lead child exposure is based primarily on animal data and limited human studies, and some of this evidence is contradictory. No studies of iron status and blood lead levels in children have accounted for environmental lead contamination and, therefore, the source of their exposure. Thus, no studies have directly determined whether iron deficiency modifies the relationship of environmental lead and blood lead. In this study, we compared blood lead levels of iron-deficient and iron-replete children living in low, medium, or highly contaminated environments. Measurements of lead in paint, soil, dust, and blood, age of housing, and iron status were collected from 319 children ages 1-5. We developed two lead exposure factors to summarize the correlated exposure variables Factor 1 summarized all environmental measures, and Factor 2 was weighted for lead loading of house dust. The geometric mean blood lead level was 4.9 microg/dL; 14% exceeded 10 microg/dL. Many of the children were iron deficient (24% with ferritin < 12 ng/dL). Seventeen percent of soil leads exceeded 500 microg/g, and 23% and 63% of interior and exterior paint samples exceeded 5,000 microg/g. The unadjusted geometric mean blood lead level for iron-deficient children was higher by 1 microg/dL; this difference was greater (1.8 microg/dL) after excluding Asians. Blood lead levels were higher for iron-deficient children for each tertile of exposure as estimated by Factors 1 and 2 for non-Asian children. Elevated blood lead among iron-deficient children persisted after adjusting for potential confounders by multivariate regression; the largest difference in blood lead levels between iron-deficient and -replete children, approximately 3 microg/dL, was among those living in the most contaminated environments. Asian children had a paradoxical association of sufficient iron status and higher blood lead level, which warrants further investigation. Improving iron status, along with reducing exposures, may help reduce blood lead levels among most children, especially those living in the most contaminated environments.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Polluants du sol
/
Carences en fer
/
Plomb
Type d'étude:
Etiology_studies
/
Risk_factors_studies
Limites:
Child, preschool
/
Female
/
Humans
/
Infant
/
Male
Langue:
En
Journal:
Environ Health Perspect
Année:
2001
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique