PARTICLE pollution associated with passing trains was more likely to be caused by dust on the tracks being stirred up rather than from a particular type of train or trains with diesel engines, a NSW Environment Protection Authority report has found.
The report represents the final stage of a study that began more than three years ago in response to community concerns about the impact of coal trains on air quality in the Hunter.
The original report found there was no significant difference between the particulate levels measured from the movement of loaded coal trains and other types of trains. However, a re-examination of the data was ordered after concerns were raised about the report’s statistical analysis.
UTS statistics professor Louise Ryan, who re-examined the data, found there was a 10per cent increase in particulate matter associated with the passage of loaded and unloaded coal trains and freight trains. A further analysis found the number of locomotives had no impact on dust levels.
This finding dispelled the hypothesis that diesel exhaust was responsible for a large proportion of increased particulate levels with passing trains.
Whether or not it had rained the previous day also had a significant impact on particulate levels, indicating the increased particulate levels were caused by trains stirring up dust that had settled earlier.
The impact of the previous day’s rain was the same, regardless of what type of train was passing.
NSW chief environmental regulator Mark Gifford said Professor Ryan’s results were encouraging.
‘‘Professor Ryan’s report will inform our ongoing work in this area and complement the work being done by NSW Chief Scientist & Engineer Mary O’Kane, who is examining the impacts of coal dust pollution in the Hunter,’’ he said.
A spokesman for Professor O’Kane said the review would look at existing scientific literature, including identifying any knowledge gaps, measurement, prevention and management practices and advances in technology for sampling and monitoring air quality in the rail corridor.
‘‘There is considerable concern around coal dust and, as such, the review will be calling for public submissions – because it’s important we examine this issue with the community’s concerns front of mind.’’