Exacerbation of Childhood Asthma among Children Living in Highly- Trafficked Areas: An Unintended Public Health Consequence of Diesel- Emission Control Technology

The diesel engine, developed in the late 19th century, has played a major role in industrial growth throughout the past century. Diesel engines are light and durable, giving them distinct advantages over other forms of power. Today they are used world-wide to power such heavy duty vehicles as trains, trucks, buses, boats, and construction equipment. In a number of countries, diesel is also the power source of choice for automobiles. Diesel fuel is combusted by compressing a fuel/air mixture to its ignition temperature. Because ignition, with modern technological advances, requires no external energy source, diesel power has energy advantages over gasoline combustion. However, diesel fuel has a higher boiling point, and, being less volatile than gasoline, when combusted, produces a mixture of products that contain significantly more particulate matter than gasoline exhaust. The composition of the exhaust will vary considerably, depending on the type of vehicle, the type of fuel, and the conditions of vehicle operation, but it is always a complex mix of particulate matter and vapors