Acid rain is one of the major environmental threats since 19th century. This book reviews the 2012 progress report of US EPA (2013) and summarizes the issue in various environmental aspects. Significant reduction in the SO2, NOx emission and deposition of acid have been occurred via the active implementation of Clean Air Interstate Rule (CAIR), Acid Rain Program (ARP) and NOx budget training program (NBP). Cross state air pollution rule and litigation (CSAPR) implemented by US EPA since 2011 reduces the cross boundary movement of effluents between US and Canada. US national composite means of average SO2 annual mean ambient concentration has been declined by 85% in the period between 1980 and 2012.

Environmental problems in coastal ecosystems can sometimes be attributed to excess nutrients flowing from upstream watersheds into estuarine settings. This nutrient over-enrichment can result in toxic algal blooms, shellfish poisoning, coral reef destruction, and other harmful outcomes. All U.S. coasts show signs of nutrient over-enrichment, and scientists predict worsening problems in the years ahead. Clean Coastal Waters explains technical aspects of nutrient over-enrichment and proposes both immediate local action by coastal managers and a longer-term national strategy incorporating policy design, classification of affected sites, law and regulation, coordination, and communication. Highlighting the Gulf of Mexico's "Dead Zone," the Pfiesteria outbreak in a tributary of Chesapeake Bay, and other cases, the book explains how nutrients work in the environment, why nitrogen is important, how enrichment turns into over-enrichment, and why some environments are especially susceptible. Economic as well as ecological impacts are examined. In addressing abatement strategies, the committee discusses the importance of monitoring sites, developing useful models of over-enrichment, and setting water quality goals. The book also reviews voluntary programs, mandatory controls, tax incentives, and other policy options for reducing the flow of nutrients from agricultural operations and other sources.

This book provides a unique overview of research methods over the past 25 years assessing critical loads and temporal effects of the deposition of air pollutants. It includes critical load methods and applications addressing acidification, eutrophication and heavy metal pollution of terrestrial and aquatic ecosystems. Applications include examples for each air pollution threat, both at local and regional scale, including Europe, Asia, Canada and the US. The book starts with background information on the effects of the deposition of sulphur, nitrogen and heavy metals and geochemical and biological indicators for risk assessments. The use of those indicators is then illustrated in the assessment of critical loads and their exceedances and in the temporal assessment of air pollution risks. It also includes the most recent developments of assessing critical loads and current and future risks of soil and water chemistry and biodiversity under climate change, with a special focus on nitrogen. The book thus provides a complete overview of the knowledge that is currently used for the scientific support of policies in the field of air pollution control to protect ecosystem services.