Atmospheric Ammonia

Anthropogenic emissions of ammonia cause a host of environmental impacts, including loss of biodiversity, soil acidification and formation of particulate matter in the atmosphere. Under the auspices of the UNECE Convention on Long Range Transboundary Air Pollution, around 80 international experts met to review the state of scientific knowledge. This book reports their analysis. It concludes that threshold levels for ammonia effects have been underestimated and sets new values, it assesses the independent evidence to verify reported reductions in regional ammonia emissions, and it reviews the uncertainties in modelling ammonia, both in "hot spots" and at the regional scale.

CHAP 1 PHYSICAL AND CHEMICAL PROPERTIES. CHAP 2 CHEMICAL INTERACTIONS: TRANSFORMATIONS AND TRANSPORT MECHANISMS. CHAP 3 MEASUREMENT AND MONITORING. CHAP 4 SOURCES, CONCENTRATIONS, AND SINKS OF ATMOSPHERIC AMMONIA. CHAP 5 TRANSPORTATION. CHAP 6 TOXICOLOGY. CHAP 7 HUMAN HEALTH EFFECTS. CHAP 8 EFFECTS ON MATERIALS.

When considering biosphere–atmosphere exchange of trace gases and volatile aerosols, significant advances have been made both from an experimental and modelling point of view and on several scales. This was particularly stimulated by the availability of new datasets generated from improvements in analytical methods and flux measurement techniques. Recent research advances allow us, not only to identify major mechanisms and factors affecting the exchanges between the biosphere and the atmosphere, but also to recognize several gaps in the methodologies used in accounting for emissions and deposition in landscape and global scale models. This work aims at (i) reviewing exchange processes and modelling schemes, parameterisations and datasets, (ii) presenting a common conceptual framework to model soil-vegetation-atmosphere exchange of reactive trace gases and aerosols accounting for in-canopy transfer chemical interactions and (iii) discussing the key elements of the agreed framework.

This book is the sixth volume in the series Acute Exposure Guideline Levels for Selected Airborne Chemicals, and includes AEGLs for chemicals such as ammonia, nickel carbonyl and phosphine, among others. At the request of the Department of Defense, the National Research Council has reviewed the relevant scientific literature compiled by an expert panel and established Acute Exposure Guideline Levels (AEGLs) for 12 new chemicals. AEGLs represent exposure levels below which adverse health effects are not likely to occur and are useful in responding to emergencies such as accidental or intentional chemical releases in the community, the workplace, transportation, the military, and for the remediation of contaminated sites. Three AEGLs are approved for each chemical, representing exposure levels that result in: 1) notable but reversible discomfort; 2) long-lasting health effects; and 3) life-threatening health impacts.

Characterizes the toxicologic and adverse health effects info. for ammonia, a colorless gas with a sharp odor that is made both by humans and by nature. Ammonia is a source of nitrogen for plants and animals. 80% of all manufactured ammonia is used as fertilizer. This profile includes: (1) The examination of available toxicologic info. and epidemiologic evaluations on ammonia to ascertain the levels of human exposure for the substance; (2) A determination of whether adequate info. on the health effects of ammonia is available to determine levels of exposure that present a risk to human health; and (C) Identification of toxicologic testing needed to identify the levels of exposure that may present risk of adverse health effects in humans. Charts and tables. This is a print on demand edition of a hard to find publication.