The increased prevalence of asthma and allergy in the 'western world' during the last decades coincide with the production and use of phthalates (plasticizers) and bisphenol A (BPA) in consumer products. Toxicological and epidemiological studies have prev iously indicated an association between exposures to these chemicals and asthma and allergy. Due to the endocrine-disrupting properties of phthalates and BPA, some of the most critical exposure periods are during infancy and puberty.
The main objective o f the present project is to assess the daily exposure to phthalates and BPA in infancy and at 10 years and the subsequent risk of asthma with emphasis on gender-related differences in exposure as well as response.
Urinary concentrations of phthalate meta bolites and BPA will be analyzed in infants (age <12 months) enrolled at hospitalization due to bronchiolitis, and in 10-year-old children in the prospective birth cohort study The Environment and Childhood Asthma study (ECA) in Oslo. The chemical analyze s will be performed at the Centers for Disease Control and Prevention, USA, and at the Department of Analytical Chemistry at the Norwegian Institute of Public Health.
The end-points will be recurrent bronchial obstruction, wheeze and asthma in the follo w-up of the bronchiolitis infants 18 months after inclusion (to be completed in 2011), and new cases of asthma and allergic sensitization in the 16-year follow-up of the ECA-study (2009). Circulating estrogen and androgen levels will be included in the an alyzes assessing the effect of the endocrine-disrupting chemicals on asthma development through puberty for the ECA-participants.
For effective prevention of asthma and allergy, knowledge of causative factors is necessary. The level of exposure to phthal ates and BPA has not previously been described for Norwegian children and the results are therefore expected to be useful for health risk assessment and public advice concerning exposure to these chemicals.