<< Back 8/28/02 Key findings and conclusions of SAMI SMN Key findings and conclusions of SAMI report: 1) Sulfur dioxide, nitrogen oxides, volatile organic compounds and ammonia are the predominant emissions contributing to ozone, fine particles that cause haze and acid deposition. Coal-fired electric utility plants are the largest source of sulfur dioxide. Highway vehicles and utilities are the largest sources of nitrogen oxides, highway vehicles are the largest human sources of volatile organic compounds, and agricultural sources are the largest contributors to ammonia gas. 2) Sulfate is the largest contributor to fine particles that impair visibility. Sulfur dioxide emissions must be reduced to improve visibility. Reductions in ammonia will be beneficial for improving visibility under some sulfur dioxide control strategies. 3) The highest acid deposition occurs in West Virginia and along the North Carolina/Tennessee border at high elevations. Sulfate deposition decreased under SAMI strategies but nitrate deposition decreases were offset by ammonia increases. Sulfur dioxide reductions under the 1990 acid rain controls are not sufficient to prevent sensitive streams from acidifying. Many streams improve with the most stringent SAMI strategy, but few improve to a different fish habitat class. To reduce acid deposition in some streams in the SAMI region (NC,SC, Ky, WV, VA, Al, GA) sulfur emissions must be reduced. 4) High-elevation spruce-fir forest are most at risk from acid deposition. Large reductions in nitrogen deposition inside and outside the SAMI region are needed to reduce nitrogen saturation in these forests. Most forests in the SAMI region are not at risk from nitrogen saturation. 5) Ozone exposures are greater for forests on ridge-tops. Growth of most forest stands will not change in response to SAMI strategies and tree death is not anticipated even without additional emissions reductions. Small changes in abundance of individual species within forest stands may occur. Nitrogen oxide emissions reductions may be important to reduce ozone effects to certain species in specific locations. 6) Each state benefits from emissions reductions in that state and surrounding states. The SAMI region will benefit from emissions reductions in the Midwest, Central and Northeast regions. 7) For SAMI to accomplish its mission, emissions reductions are essential within each member state as well as outside the region.