Blood lead levels and childhood asthma.

Objective: To measure blood lead levels in children (5-14 y) with bronchial asthma, and correlate with asthma severity.

Design: Cross-sectional analytical.

Setting: Pediatric Allergy and Immunology Clinic of a Childrens hospital in Cairo, Egypt.

Participants: 200 children (127 males) with bronchial asthma and 125 age- and sex-matched healthy controls (80 males).

Procedure: Blood lead levels were measured by atomic absorption spectrophotometer technique, and were subsequently correlated with asthma severity.

Results: No significant difference in mean (SD) blood lead levels was observed between children with asthma [13.3 (4.8) ug/dL] and control group [11.4 (3.9) ug/dL]. 190 children (58.5%) had elevated blood lead levels (>10 ug/dL), with no significant difference between patients (60%) and controls (56%). Patients with elevated blood lead levels had significantly higher frequency of eosinophilia (66.7%) and increased total immunoglobulin E (83.3%) compared to other patients with blood lead levels <10ug/dL (10% and 43.8%, respectively). Patients of asthma with elevated blood lead levels had higher grades of severity of asthma compared to those with blood lead levels <10 ug/dL.

Conclusions: Blood lead levels are not significantly associated with diagnosis of asthma but elevated blood lead levels seem to be associated with increased asthma severity and higher frequency of eosinophilia and elevated immunoglobulin E levels.