Diesel Engine Exhaust Emissions - Cancer Risk
Employers are required to prevent or, where that is not reasonably practicable, adequately control exposure to materials in the workplace that cause ill health like dermatitis. Exhaust emissions from diesel engines are made up of a complex mixture of gases, vapours, liquid aerosols and soot particles. It contains many known carcinogenic substances such as Polycyclic Aromatic Hydrocarbons (known as PAHs). These PAHs are adsorbed onto the soot which makes them easy to inhale.
The quantity and make-up of DEEEs depends mainly on the engine type and setting, how it is maintained, fuel quality, the demands placed on the engine and temperature that it is working at. Three different types of visible smoke may be produced:
- blue smoke (mainly oil and unburnt fuel) which indicates a poorly serviced / tuned engine
- black smoke (soot, oil and unburnt fuel) which indicates a mechanical fault with the engine
- white smoke (water droplets and unburnt fuel) which is produced when the engine is started from cold and disappears when the engine warms up
The major source of DEEEs on a construction site is likely to be from generators and heavy vehicles like lorries, excavators or telehandlers. The more significant risks are linked to longer periods of work with this equipment in enclosed spaces and / or situations where there is blue or black smoke.
Breathing DEEEs can cause a number of ill-health effects. Short-term exposure may cause eye or respiratory irritation. This should stop when you are in fresh air. Longer periods of exposure, in particular to any blue or black smoke, can lead to coughing, chestiness and breathlessness.
There is also evidence that repeated exposure to DEEEs over many years can increase the risk of lung cancer. HSE commissioned research highlighted it as a significant risk to construction workers from DEEEs, estimating that over 200 died prematurely in 2005. It is important to note that this estimate is based on past exposures up to 50 years ago. Engine and fuel technology has changed significantly since then. However, risks remain that need to be controlled.