The Handbook is specifically designed to be used in the context of the World Bank Group's environmental policies, as set out in Operational Policy (OP) 4.01, "Environmental Assessment," and related documents. It consists of three sections. Part I contains a summary of key policy lessons in pollution management, derived from practical experience inside and outside the World Bank Group. Although Part I is aimed primarily at government decision makers, other readers will derive considerable benefit from a better understanding of the issues facing government agencies. Part II presents good-practice notes on implementation of policy objectives, based on experience with World Bank Group projects and on lessons from the policies and practices of other agencies and organizations in this field. Part III provides detailed guidelines to be applied in the preparation of World Bank Group projects. The guidelines, which cover almost 40 industrial sectors, represent state-of-the-art thinking on how to reduce pollution emissions from the production process. In many cases, the guidelines provide numerical targets for reducing pollution, as well as maximum emissions levels that are normally achievable through a combination of cleaner production and end-of-pipe treatment.