Reducing high levels of particles in tunnels

A new study from Sweden’s National Road and Transport Research Institute (VTI) which aims to improve understanding of the differences between inhalable particles in highway versus railway environments has indicated that older types of trains produce more particulate emissions in railroad tunnels than do newer ones. Dust binding, improved paving and reduced studded tyre use could reduce coarse particle levels in road tunnels.
March 1, 2017 Read time: 2 mins

A new study from Sweden’s National Road and Transport Research Institute (5230 VTI) which aims to improve understanding of the differences between inhalable particles in highway versus railway environments has indicated that older types of trains produce more particulate emissions in railroad tunnels than do newer ones. Dust binding, improved paving and reduced studded tyre use could reduce coarse particle levels in road tunnels.

The tests were carried out in Sweden at Arlanda Central station beneath Arlanda Airport and in the Söderleden road tunnel in central Stockholm. The results indicate that the environment of the studied railroad tunnel is characterised by peaks in coarse particle concentration. Some trains can be tied to emissions of ultrafine particles which consist mainly of iron, with lesser amounts of copper, zinc and other metals.

The main focus of measures to remedy high particle counts in railway tunnels has so far been on preventing exposure by separating trains from platforms or using ventilation to remove polluted air, but few studies have examined the means available to prevent the emissions themselves.

According to VTI researcher Mats Gustafsson, the study demonstrates that it is possible to reduce particulate emissions by identifying and improving train types as well as individual trains and their characteristics.

Road tunnels are characterised by high levels of ultrafine particles and high levels of coarse particles when conditions are dry. Because the traffic in such tunnels is more intense than in railroad tunnels, the particle levels are more consistently high during rush hours.

“The options available to combat coarse particles in road tunnels comprise reduced studded tyre use, better paving, and efficient dust binding and cleaning”, said Gustafsson.

The ultrafine particles that occur in high concentrations derive from vehicle exhaust and can be addressed by reducing traffic volumes, improving exhaust treatment, and lowering the proportion of heavy traffic, he says.

Air Quality & Weather Systems

Related Content

  • July 20, 2015
    New report indicates reduction in London’s pollution
    A new report, produced by experts at King's College London, for the first time quantifies the health and economic effects of the air pollutant nitrogen dioxide (NO2), where all previous studies have focused on particulate matter (PM2.5). Combined together the effects of both pollutants reveal a higher health impact than previously estimated after taking into account this further pollutant. The study also found that nearly half the health impacts are caused by air pollution outside London such as diesel
    Read More
  • September 13, 2016
    Volvo and KPMG find buses are key to urban air quality
    Buses can play a key role in the battle to improve air quality in towns and cities as David Crawford discovers. A city with a population of half a million would gain about US$12.3 million in annualised societal savings if all its buses ran on electricity instead of diesel. This is the conclusion of a wide-ranging analysis carried out by Swedish bus manufacturer Volvo Group and global business consultants KPMG.
    Read More
  • March 15, 2016
    Rethink required to reduce road transport’s environmental impact
    Against a background of a renewed focus on limiting the rise in average temperatures, Colin Sowman looks at a project that is taking a holistic approach to the environmental impact and safety of road transport. At the COP21 meeting in Paris last December, almost 200 nations agreed to reduce greenhouse gas emissions in an effort to keep the rise in global temperatures to 2°C) compared with pre-industrial levels. The transportation sector is a major contributor to the production of CO2, one of the main green
    Read More
  • August 15, 2014
    Reducing congestion essential to help buses meet EU NOX targets
    Tailpipe data firm Emission Analytics has issued a warning to bus and vehicle fleet owners planning to retrofit their vehicles with nitrogen oxide (NOX) reducing equipment, as stringent real-world analysis is need to ensure they meet the EU emission targets. The firm says the Department for Transport (DfT) support for local authorities with up to £500,000 of funding from its £5 million Clean Vehicle Technology Fund is a positive step. However, the methods by which it monitors the NOX produced needs to be
    Read More

Highlighted Content