Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Diesel engine emissions are a mixture of harmful chemicals including tiny toxic particles and hazardous gases (e.g. nitrogen oxides, benzene, sulfur dioxide), resulting from the combustion of diesel fuel in diesel engines, found in buses, automobiles, trucks, trains, ships and other means of transport. Recently, the World Health Organisation's cancer research agency has classified diesel exhaust as cancer-causing, linking it to lung and bladder cancer. Learn more about diesel exhaust and its health effects in this book.