Lay summary
New Zealand has high rates of asthma and hospitalisations for asthma. A follow up is proposed for a study carried out in 450 urban Wellington homes, to examine whether the recently discovered protection for wheeze by 'farm-like' microbes found in the initial study, have resulted in less asthma at aged 12, than those who did not have 'farm-like' dust. Additionally, refining the Finnish 'farm-like' dust and investigating what factors create farm like dust in urban environments is proposed. Understanding these factors gives us our first opportunity to confer the protective effects of farming to urban settings, by modification of the early infant indoor environment.