Diesel Engine Exhaust Emissions in the Rail Sector

Fuel and engine technology has improved significantly over the years but health risks associated with exposure to diesel engine exhaust emissions (DEEE) can still exist.

Health effects associated with DEEEs

The short-term health effects associated with exposure to DEEE can be irritation of the eyes and the respiratory tract. If there is significant blue or black fume present in the working environment this can cause coughing, chestiness and breathlessness.

The longer-term health effects can be serious as DEEEs are classified as Group One (substances that have definite links to cancer in humans) by the International Agency for Research on Cancer (IARC).

Control of Exposure

Within the Office of Railway Regulation (ORR) programme, it specifically refers to the railway environment and highlights the need for employers to ensure that exposure to DEEE is adequately controlled by strict adherence to the COSHH hierarchy of control. 

DEEE exposure also falls under The Control of Substances Hazardous to Health (COSHH) Regulations 2002, as amended, which states “if exposure to a substance cannot be prevented, it is to be adequately controlled under the hierarchy of control”.

The COSHH risk assessment for individual situations and activities, using the hierarchy of control, should define the measures required to reduce DEEE exposure to as low as reasonably practicable (ALARP) in the workplace. The HSE also publishes a guide to the control of DEEE in the workplace (HSE publication HSG187: Control of Diesel Engine Exhaust Emissions in the workplace).  

Exposure Monitoring to DEEEs

SOCOTEC has a proven track record in providing occupational hygiene services to the rail sector. In order to monitor DEEEs, SOCOTEC’s national team of occupational hygienists can employ a variety of instruments and sampling media to capture the various components of the diesel fume and gases.

The exact tests carried out will vary, depending on each situation. Elemental carbon and combustion gases are seen as the key markers for DEEE but some additional tests can also include analytical scans for:

• Respirable particulates
• Aldehydes and Ketones
• PAHS (Polycyclic Aromatic Compounds)
• VOCs (Volatile Organic Compounds)

Real time gas monitoring and aerosol monitoring instruments can provide an on-site indication of diesel fume levels and if these could be an issue. This is supported by air sampling for various components on adsorbent tubes and filters, with further laboratory analysis, to accurately identify the specific components.

When receiving the results, these are compared against UK Workplace Exposure Limits or international Occupational Exposure limits. SOCOTEC then assess the risk for those exposed to DEEEs, and make recommendations on control measures to reduce the risk further.