Brown Coal Mine Fire-Related Fine Particulate Matter and Medical Service Utilisation in Australia: A Time Series Analysis

Background: There is a knowledge gap as to whether coal mine fire smoke has adverse health risks. This study aimed to assess the association between coal mine fire-related PM2.5 and health service utilisation across five localities in South-eastern Victoria, Australia after wildfires ignited a coal mine fire which burned for six weeks in 2014. Areas in the immediate vicinity of the mine were estimated to experience hourly mine fire-related PM2.5 concentrations of up to 3700 μg/m3.Methods: Data on medical service utilization between 2012 and 2016 were collected from the Medicare Benefits Schedule; a national database of use of medical services. Spatially resolved PM2.5 concentrations were retrospectively modelled using The Air Pollution Model (TAMP), a dispersion model, coupled with a Chemical Transport Model. Poisson distributed lag time series analysis examined the association between daily mine fire-related PM2.5 concentrations and medical service utilization for respiratory, cardiovascular and mental health conditions. Confounders included seasonality, long-term trend, day of the week, maximum ambient temperature and public holidays.Results: Positive associations were found between mine fire-related PM2.5 and all medical service types, after lag 2-5 days. A 10 μg/m3 increase in PM2.5 was associated with a 19% (95%CI 16-22%) increase in the risk of long and short General Practice consultations, 29% (17-42%) increase in cardiovascular services, 27% (10-46%) increase in respiratory services and 13% (4-22%) increase in mental health consultations.Conclusions: Coal mine fire-related PM2.5 exposure was associated with increased use of medical services for respiratory, cardiovascular and mental health. These findings can inform the development of future public health policy responses in the event of major air pollution episodes.