Examining two landmark case studies at the two national borders on the continent, Wirth (Latin American studies, Stanford U.) shows how environmental diplomacy, citizen action at the grassroots level, and the role of science, industry, and the law converged into the current approaches to pollutant pathways. The Trail smelter conflict of 1927-41 pitted US farmers against a Canadian smelter, and the Gary Triangle confrontations of the 1980s resulted in closing a US smelter in Arizona and imposing stricter standards on two Mexican smelters in Sonora. Annotation c. Book News, Inc., Portland, OR (booknews.com)