Air Quality in Association With Rural Coal Mining and Combustion in New South Wales Australia

Purpose Rural areas may face under-recognized threats to air quality. We tested 2 hypotheses that 1) rural areas in New South Wales, Australia, would have better air quality than metropolitan Sydney, and that 2) the rural Upper Hunter region characterized by coal mining and coal combustion would have worse air quality than other rural areas of the state. Methods We analyzed 2017 daily mean values for New South Wales, Australia, for particulate matter (PM2.5 and PM10), sulfur dioxide (SO2), nitric oxide (NO), nitrogen dioxide (NO2), and NOx (sum of NO and NO2). Forty-six air monitoring stations were grouped into 6 rural and urban regional areas. Linear regression models examined pollution levels in association with rural and urban regions and meteorological covariates. Results Findings show that daily mean pollutant levels in the rural Upper Hunter were the highest of all regions, and were significantly higher than metropolitan Sydney, with and without control for weather conditions, for every pollutant. For example, daily mean PM2.5 was 8.64 mu g/m(3) in the rural Upper Hunter, compared to 7.23 mu g/m(3) in metropolitan Sydney. Conclusions Results highlight the need to consider both urban and rural sources of pollution in air quality studies, and appropriate policy steps to address likely rural air pollution from coal mining.