Status of Air Quality and Effects of Atmospheric Pollutants on Ecosystems in the Pacific Northwest Region of the National Park Service

摘要

This report addresses the objectives by providing a summary of current and historical monitoring data for pollutants, a synthesis of knowledge on ecological effects from atmospheric pollutants, and to the extent feasible, a park-specific assessment of pollution vulnerability. Guidelines presented in this report should also be applicable to similar ecosystems or areas with similar resources. The air quality in the region generally is very good compared to other areas of the United States. The principal air masses are derived from the atmosphere over the Pacific Ocean, and as a consequence, accumulated air pollutant loads are low. Emissions of principal air pollutants within the Pacific Northwest are low relative to other regions, and trends in some air quality indicators seem to be stable or improving. Although precipitation quality in the region generally is high, it is not uniform. Nonmarine sulfate and hydrogen ion concentrations in precipitation for at least portions of the Washington Cascades are slightly elevated above background concentrations (background concentrations are approximated by precipitation measured on the west side of OLYM) and are cause for concern in MORA and NOCA.