Further environmental aspects of the use of diesel-powered equipment in coalmines. Final report on CEC Research Contract 7260-04/29/08

Diesel powered equipment has been used in coalmines for over forty years. In the United Kingdom diesel locomotives running on narrow gauge tracks or monorails have been most common but diesel free steer vehicles (FSV’s) are now becoming increasingly common. Diesel exhaust emissions contain many potentially hazardous chemicals, including nitrogen dioxide, sulphur dioxide, carbon monoxide, aldehydes, polyaromatic hydrocarbons and nitrated polyaromatic hydrocarbons. There is therefore much concern about the potential adverse effects on general respiratory health from diesel exhaust emissions and their possible carcinogenicity.In UK coalmines this concern has recently centred around the use of diesel FSV’s.Previous work showed that, in one drivage, diesel FSV’s gave rise to higher levels of oxides of nitrogen and carbon monoxide than those found in similar drivages where diesel locomotives were used. The present study was designed to investigate this further. Its aims were to assess the environmental impact of the use of free steer vehicles in British coalmines so that some assessment of potential adverse effects on health could be made.The study was based on six, one week surveys of nitric oxide, nitrogen dioxide, carbon monoxide, formaldehyde, respirable dust and polyaromatic hydrocarbons. These were carried out in three collieries where diesel FSV’s are used to transport men and materials. Sampling was carried out in drivages, face return roadways, transfer points, garages and at the pitbottom. Static sampling procedures were adopted with samplers normally placed close to the workstation. In the case of vehicle drivers, samples were collected in the cabins.In all three collieries levels of noxious emissions were low. The highest measured concentrations of nitrogen dioxide, carbon monoxide and formaldehyde were 0.3 ppm, 15 ppm and 0.5 ppm respectively. (The current UK occuaptional exposure limits for these gases are 3 ppm, 50 ppm and 2 ppm respectively). A range of polyaromatic hydrocarbons were analysed. These included pyrene,benzo[a]anthracene, chrysene, benzo[a]pyrene and benzofluoranthene. Only traces of these materials were detected, all at concentrations below 80 ng/m3. These results were primarily due to good ventilation, the care taken in routine vehicle.