A study of the fume exposure of mine workers from diesels in drivages in relation to varying mining conditions and the effects on their health. Final report on CEC Contract 7256-33/028/08

The environmental impact of the use of diesel-powered equipment in twelve drivages has been assessed. These drivages covered a range of mining and ventilation conditions. Diesel locomotives of different manufacture, power (40 – 100 hp), engine type (direct and indirect injection) and transmission (hydraulic and direct drive) were encountered and free steering vehicles were used in two of the drivages.Environmental surveys were carried out in each drivage to measure airborne concentrations of oxides of nitrogen, carbon monoxide, hydrocarbons, formaldehyde, carbon dioxide as well as respirable’ dust and associated benzo(a)-pyrene. These results were considered in relation to the range of mining and ventilation conditions encountered. In addition, the exhaust emissions of the locomotives were measured according to statutory requirements at the start of each exercise. Occasionally the emission limits for various gases were exceeded but no attempt was made to re-tune the engines especially for the surveys.Under normal working conditions the use of diesel locomotives in drivages appears to give rise to low levels of atmospheric pollution and it is probable that any health risks from diesel locomotives in drivages are slight. Current mining and ventilation practices in drivages with legal requirements on exhaust gas quality appear to offer adequate protection to the drivage work force.On the other hand, the load haul dump vehicles used at one colliery gave rise to very much higher levels of oxides of nitrogen in the drivage than observed elsewhere during the project. This occurred despite the concentrations of oxides of nitrogen and carbon monoxide in the vehicles’ exhaust being very low. Exposures of miners to diesel exhaust fumes might be unacceptably high if cases occur where the diesel exhaust emissions are close to the statutory limit. The environmental impact of the use of free steer vehicles in coal mines should be further investigated to determine whether this type of problem occurs and to consider means of reducing fume exposures, if necessary.A short investigation of lachrymatory problems from rack locomotives in main roadways was also carried out. Formaldehyde and, perhaps, other aldehydes appeared to be the source of these problems. The relatively high concentrations of these gases probably arose from poor dispersion of the locomotive exhausts rather than from any unusual feature of the exhaust composition. When the lachrymatory effects were in evidence the locomotive was running in the same direction as the ventilation, under heavy load, and with the engine at high speed. Other instances of lachrymatory problems have been noted in coal mines, not necessarily related to rack locomotives. A fuller investigation of diesel-related lachrymatory problems would be worthwhile.