Respondents will be asked the following question: "Is there a member of the household between ages of 1 to 85 who has had asthma ever diagnosed by a physician". If the response is affirmative the study assistant will ask if the participant in question can continue the conversation directly (parents in case of children). Eligible participants (or in the case of children their parents or guardians) will be informed of the objectives of the study, verbally consented, and then screened for eligibility based on age and history of asthma. Participants who meet eligibility criteria and verbally consent over the phone will be asked to come to the study laboratory (one at Vancouver and one at Kelowna, corresponding to the two Census Sub-Divisions) and the participant will receive a detailed explanation of the study and the study consent form at that time.