Introduction: This paper describes the impacts of the closure of a major industry on air quality in the Lower Hunter Region. BHP Rod and Bar was recognized as the most important source of particulate matter (PM10, bsp), nitrogen dioxide (NO2), and sulphur dioxide (SO2) in Newcastle before it closed in October 1999. Objective: This study investigated the impacts of the closure of a major industry, a steel works in Newcastle, on air quality in the Lower Hunter Region, New South Wales.
Method: A combined three-station data set for these pollutants for 3.5 years before and after closure allowed a comparison of daily and data set averages, using both the measured data, and a Mixed Model to calculate significant changes in the time series by month.
Result: PM10 increased after BHP closure by 13.2%, an unexpected result, but the post closure data set was influenced by summer bushfires. bsp decreased by 10.2%, reflecting the reduction is emissions due to industrial burning processes. This result was verified by a separate PM2.5 data set which showed significant reductions in elemental carbon and soil source components. SO2 concentrations dropped by 40.2% after closure, a change which verified the importance of BHP as a source. Despite the industry being a major source of NO2, there was no significant change of this pollutant after closure, suggesting dominance of other sources.
Conclusion: Air pollution in the region is caused by different sources. Further research into the role of meteorology and quantifying changes in the range of sources is recommended