In most states there is a critical need to build evidence-based communication capacities. Communication strategies need to be developed and implemented. Such strategies should engage all players, i.e. policy-makers, the media, NGOs, environmental educators and professionals, and private sector advertisers. These communication networks should be used to deliver key environmental health messages. Communication is not a one-way process - it should stimulate debate and dialogue and feed back into decision-making processes. WHO/EURO is developing a glossary of environmental health terms, to assist common understanding. States are encouraged to use the glossary and to develop equivalent glossaries in their own national languages.