Acute respiratory infection risk associated with exposure to outdoor PM{{10}} emissions from domestic heating.

Aim: Woodsmoke exposure has known adverse respiratory health effects. However, most studies are based on exposure in developing countries or developed cities. Woodburners are commonly used for domestic heating in New Zealand, and in some areas they impact air quality. We investigated whether woodsmoke exposure at levels encountered in a mid-size township has health effects.

Method: We performed a time-stratified case crossover analysis of 1,870 general practitioner (GP) visits for acute respiratory infections (ARI) over five consecutive winters (May-August 2014-2018). Daily air concentrations of particulate matter less than 10 μm (PM{{10}}) were obtained from a fixed-site monitoring station. Conditional logistic regression was used to estimate OR and 95% CI after adjusting for the effects of temperature.

Results: A 10 µg/m[[3]] increase in PM{{10}} concentration was associated with 8% (95% CI 1%-15%) and 20% (95% CI 4%-38%) increases in the odds of a GP visit for an ARI within 24 hours for women and girls, and Māori of both sexes, respectively.

Conclusion: Woodsmoke pollution may negatively affect the respiratory health of residents in mid-size towns. However, those most affected by woodsmoke are also likely to be most affected by woodburner phase-out policies. Air quality and housing policies must be integrated to meet a mutual goal of improved health.