The project will establish a resource of detailed asthma phenotypes from birth to 8.5 years based on available questionnaire and objective data. The resource will be linked to a wide range of information on environmental exposures before and after birth to address the following general hypotheses:

1. Different environmental exposures in early life are associated with different phenotypic outcomes of asthma.

2. Outcomes are determined by the timing and the magnitude of exposures and by their interactions with (a) other environmental risk/protective factors and (b) family history of asthma/atopy.

3. Exposures at different stages of development (prenatal, perinatal, postnatal) have differential effects on asthma outcomes.

The outcomes will generate new hypotheses about the origins of asthma in early childhood that will be used as the basis for targeted proposal to examine interactions between genetic predisposition and environment in the development and phenotypic expression of asthma in childhood.