Now, in the waning days of Clinton's tenure, Browner is taking a critical, long overdue step by establishing dramatically cleaner standards for the diesel engines that power trucks, buses and some cars. When the standards are in full effect a decade from now, the rolling smokestack that is the current big rig should be a thing of the past. For the first time, trucks and buses will be required to have both pollution control devices on the engines and the cleaner fuel that is essential to make them work. By 2007, fuel makers would have to reduce the sulfur content in diesel by 97 percent. The net effect would be a 95 percent cut in emissions of nitrogen oxide, a key component to ozone pollution and smog, and a 90 percent reduction in soot, known technically as particulate matter.
Recent studies link very small particles in the air to cancer.
Vehicle-makers have seen these tougher standards coming for a while and seem resigned to them. The fuel makers, predictably, are not happy. They had hoped to get by with a 50 percent reduction in sulfur, and complain that the virtual elimination of it will cost too much in refinery overhauls. Refineries do indeed have their work cut out for them, because they are already committed to delivering lower sulfur gasoline. That's why EPA was right to allow for a generous phase-in time.