Six million tons of oil are spilled every year, according to this ""Full-Color First Book,"" an excellent introduction to the spills' origins and to clean-up efforts and environmental effects. Especially interesting are the many photos of the 1989 Exxon Valdez disaster and clean-up machines and methods including skimmers, booms, vacuum pumps, absorbents, burning, and dispersants. A useful beginning title on this contemporary problem. Specialized terms are printed in boldface and defined in a glossary. Brief, superficial list for further reading; index.