Modelling of Particle Emissions from Rail Maintenance

Sammanfattning

High levels of particulate matter (PM) in the air has been shown to have several negative effects on human health, especially when exposed to them in the long term. One location in which the PM-levels are higher than the urban background level is on underground metro platforms. The goal of this study was to model where the emissions were coming from on metro stations, specifically by looking at emissions from regular maintenance. All PM-level data and maintenance logs used were collected as part of an earlier study. The data points were filtered to ensure maintenance was the only factor impacting the PM-level. The results show that the mean PM-level is higher on days with maintenance when compared to days with no maintenance, and a T-test performed on the data-sets returned a value of around 0.01, showing a statistically relevant difference in the two groups. However, when looking at the distribution of PM-levels, with the exception of some extreme outliers the distribution is very similar when comparing days with maintenance and days with no maintenance. This could indicate that a majority of maintenance activities have a negligible effect on the PM-level on stations, with only a few types of maintenance leading to a harmful increase.