Exhaust gas that they produce smaller quantities of toxic pollutants (e.g. oxides of nitrogen) than petrol and diesel engines of the same power. They produce larger quantities of carbon dioxide but less carbon monoxide due to more efficient combustion. Researchers from the University of California, Los Angeles School of Public Health say preliminary results of their statistical study of children listed in the California Cancer Registry born between 1998 and 2007 found that traffic pollution may be associated with a 5% to 15% increase in the likelihood of some cancers. A World Health Organization study found that diesel fumes cause an increase
North British Locomotive Company Railways (BR) designs pre-TOPS British Rail Class D3/1 (later D3/4), and later designated Class 21, Class 22, Class 41, Class 43 (Warship) and Class 251 (Blue Pullman) None of these were particularly successful: constructional shortcomings with the MAN engines made them far less reliable than German-built examples. A typical example of this was the grade of steel used for exhaust manifolds in the Class 43s – frequent manifold failures led to loss of turbocharger drive gas pressure and hence loss of power. More importantly, the driving cabs of the locomotives would fill with poisonous exhaust fumes. BR returned many North