EPA’s Efforts to Reduce PM
Reducing emissions of PM remains a crucial component of EPA’s strategy for cleaner air and improved visibility. Over the last two decades, significant reductions in PM emissions from some industrial processes have been achieved. However, meeting EPA's national health-based air quality standards continues to be an important step to ensure the air is safe to breathe. EPA, States, tribes, and local governments are working together to reduce emissions of PM through several control programs.
National health-based air quality standards
Breathing PM can cause serious health problems. Much of the nation's focus has been on complying with EPA's national standards for larger-sized or “coarse” particles in the air. Coarse particles come from sources such as wind blown dust and unpaved roads. Coarse particles can accumulate in the respiratory system and aggravate health problems such as asthma.
In 1997, EPA strengthened its' health protection standards for PM by adding an indicator for even smaller-sized or “fine” particles. For the latest on EPA's regulation to reduce particle pollution, log onto EPA's web site. Fine particles generally come from industrial fuel combustion and from vehicle exhaust. We now know that fine particles are most closely associated with increased respiratory disease, decreased lung functioning, and even premature death.
EPA has begun collecting monitor data at locations across the country to determine the levels of these smaller-sized particles in the air.
Cleaner diesel engines
Prior to 1994, newly manufactured diesel trucks and buses produced higher levels of PM. Starting with model year 1994, engines for new diesel trucks have been built to meet EPA's emission standards, reducing PM emissions by 90 percent. Remodeled buses also reduced PM emissions even more than trucks. EPA is continuing to work with manufacturers to further reduce emissions from diesel engines, including non-road engines such as construction equipment.
Presently, there are two developments which, when enacted will improve air quality in terms of reducing PM emissions from heavy-duty on-road and off (or non) road diesel powered vehicles. These regulations will help achieve public health standards through the introduction of new emission standards that will result in significant reductions in PM and oxides of nitrogen:
- 2007 Highway Heavy Duty Clean Diesel Program: Starting in 2007, on-road diesels must be standards that reduce the parts per million (ppm) of PM and NOx. Key elements of the program include engine standards and clean (low sulfur diesel fuel standards. This will result in a 90% plus reduction in these pollutants in a ramp-up during the 2007-2010 time frame.
- Off or Non-Road Vehicle Standards: Standards are under review by the EPA that will require emissions certification of heavy duty vehicles used in non-road situations.
Visibility protection
EPA issued visibility protection regulations in 1999 to reduce emissions that cause haze over large areas of the country. “Regional haze” affects some of our nation's most treasured areas such as Grand Canyon, Yellowstone, Acadia and Shenandoah. The haze is formed by pollution particles in the air, which can be carried by the wind and cause problems hundreds of miles away. These regulations call for coordinated state efforts to develop long-term strategies aimed at returning visibility to natural conditions.