Here, the term 'chemical substances' relates to a range of very different substances in the form of organic compounds and heavy metals. Some chemical substances are released directly into the environment by man with the purpose of influencing biological processes, e.g. pesticides. Others form by themselves through unintended chemical processes, e.g. PAHs and dioxins are formed in the combustion of oil, coal, waste and wood. Others again are used in the products that form part of modern life and may be released to the surrounding environment, e.g. plasticising agents.

It is important to check on an ongoing basis whether there actually are or will be harmful effects associated with these chemical substances. Many activities at NERI focus on chemical substances, including the following:

• Analysing new substances for potential damaging effects as part of the approval procedure before the substances enter into production.
• Being continually on the look-out for suspicious substances among the many thousands of substances that are in circulation.
• Examining the suspicious substances in more detail to establish whether measures should be effected to reduce or remove these substances.
• Continual investigation of the occurrence of suspicious substances in the environment through monitoring programmes.
• Investigating directly whether damage or harm is caused to the natural environment or man as a consequence of chemical substances.

Furthermore, social strategies that continuously use the existing knowledge on chemical substances to best advantage are required to prevent or minimise the negative effects on the environment and human health via adoption of different initiatives. NERI is also involved in developing the tools that can support this work, determining the best social strategy.