The commonwealth has applied for a $1.5 million Clean Diesel Emerging Technology grant through the American Recovery and Reinvestment Act to upgrade two marine diesel engines in the Pittsburgh area, Governor Edward G. Rendell announced. "Diesel engines play important roles in our everyday lives, but old, inefficient engines are major sources of air pollution that make it difficult for many people to breathe," Governor Rendell said. "Diesel emissions are not limited to our highways and factories. Marine vessels used at the Port of Pittsburgh are essential to moving freight along the Allegheny, Monongahela and Ohio rivers, but they also diminish the region's air quality.