Based on the proceedings of the 3rd US-Dutch International Symposium held in Nijmegen in 1988, this book discusses a wide range of topics including emissions, transport and transformation of precursors of ozone and of ozone itself, distribution of ozone, deposition of ozone at the earth's surface and its effects on man and the environment. Also described are present and future policy measures to reduce ozone in the lower atmosphere and to protect the ozone layer in the stratosphere.