Atmospheric Pollution at Railway Tunnel Worksites

Since AEF was founded in 1933, its Environment and Prevention team has been working to evaluate rail sector chemical, health and environmental risks and find ways of keeping them under control.

Air quality in tunnels where railway works operations are in progress is a recurrent problem. Gas and particle emissions from diesel works vehicles and from the works themselves can reach quite high levels. In addition, ventilation aspects are not always fully under control. Tunnel air may therefore represent a risk for site operatives, which is why it is vital to take preventive action to ward off potential health and safety threats.

AEF is therefore frequently involved in monitoring gas and particle emission levels on different worksites, using its skills and experience with regard to air quality to provide support and assistance to contain the potential effects of pollution on staff present on the sites.

By way of example, RER Line C caters to one of the highest volumes of traffic in Greater Paris with more than 540,000 passengers in transit daily. The CASTOR programme launched in 1996 consists of taking advantage of the summer holiday period to embark on work to consolidate the foundations of the underground section between Champ de Mars and Paris Austerlitz, undermined by the repeated fluctuations in the level of the waters of the neighbouring River Seine. The programme also includes rail, track, switch and electrical equipment replacement and renovation operations. CASTOR is also the opportunity to undertake preparatory station modernisation, maintenance and accessibility compliance work. Over 100 employees are deployed for these various operations and their safety is a matter of top priority.

While work is in progress, AEF has the task of monitoring air quality. The gases and dust emitted by the works vehicles and by the works themselves are compared with the statutory limiting values. By measuring exhaust gases in real time, it is possible to ensure that the air breathed by staff working on site remains of satisfactory standard. Dust is submitted to post-works analysis in the laboratory. The results are then used to prepare the programme of operations for the following summer, adapting the ventilation system to ensure cleaner air, introducing new individual protection equipment or altering site working arrangements.

The Test and Measurement Laboratory (LEM), a further partner of Eurailtest, can also offer this type of service. It is particularly involved in the major worksite operations carried out each year by the RATP on RER Line A.

For more details about the services proposed by Eurailtest with regard to underground air quality, see our product page here