Housing and health (New Zealand)

Abstract

A belief based on a personal experience that asthma incidence in New Zealand is interrelated with the indoor environment, led the author to establish the study between asthma and housing. A considerable period of time was spent first on studying the roots of the two issues, asthma and New Zealand housing. The historical experience showed that health and housing problems at the national level in the 19 th century in England were solved by state interference. The architectural background of this study created a need to cover some medical knowledge to understand the causes, symptoms and cure of asthma, if any. This knowledge was crucial while monitoring houses, designing the questionnaire, and analysing results. Two stages of monitoring were achieved in 2000 and 2001. In addition to the monitoring, there was an attempt to find out as much information as possible about any issues related to the health conditions, especially the respiratory disorders, and the houses. The study of housing included building construction, house dust mite allergen levels in the carpet, building drawings, and other issues in preparation for the next stage of analysis. The overwhelming quantity of information gathered about the 30 houses investigated in 2000 was so confusing that no statistical software package was seen as a perfect way for analysing it. It was decided then to establish comparisons between each factor investigated and asthma presence. Also, in most of the cases, the correlation between more than one factor with asthma rates was examined. The investigation of the relations between many issues and asthma showed that there were links between asthma incidence and some indoor conditions of houses. Raised timber floors, which were found in most of the houses to be un-insulated, and in all the cases to be on unprotected ground, were found to have a strong relation with asthma incidence. In these houses, it was found that high asthma incidence was related to a higher level of moisture indoors. Asthma incidence in houses having old carpet, moulds, pets, or smokers indoors was higher than asthma incidence in houses without these. Old houses were found to have more asthma incidence than new houses. All the allergen levels in the carpets were extremely high and they were all above the allergen levels induced by house dust mites that can provoke asthma in susceptible individuals. Based on the knowledge gained about the defective factors in housing affecting asthma, upgrading of the houses was designed. A house was chosen to be upgraded in three stages, each stage providing a different level of insulation. The upgrading costs were compared with the current national costs of health and heating to see what level of upgrading would be logical and cost-effective. National costs and savings were estimated in four cases each with different level of insulation. It was decided at the final stage of the study that insulating ceilings and floors in addition to other basic upgrading factors would provide savings in health and heating costs and would result in less CO2 emissions to the atmosphere of New Zealand.