Information concerning indoor air quality and mitigation of the problem in both new and existing commercial buildings is summarized in Part 1 of the book. Part 2 reflects information currently available on the health effects associated with each of the selected contaminants. Part 3 presents suggested sampling procedures and analytical approaches for known and suspected carcinogens found in indoor air. Parts 1 and 2 were prepared for the US Dept. of Energy, Part 3 for the US EPA.

A short historical review shows that treatment plants have been developed only after problems have occurred. The high diversity pollutants of totally different origins and natures, and chemical and biological characteristics require different tools. A good approach is to select one basic tool and try to integrate tools for other tasks within this main tool. The main tool will be in almost every case (for municipal wastewaters) an activated sludge plant surrounded by other elements of polishing or for the elimination of nitrogen, phosphorus, etc., according to the local situation. Some tasks like elimination of pathogens or eggs of intestinal worms, are automatically performed to a high degree in connection with the task of eliminating degradable organics. Special wastewaters with certain pollutants have to be treated at the place of their origins. For wastewater of agricultural production direct or indirect recycling should be favoured. For wastewater of industrial background containing toxicants, treatment must be economically included in the production process of the main product. Besides this, there appears a multitude of organics of unknown chemical composition and environmental significance. They should be permitted for public application only after lab tests have proved their degradability and the conditions of their degradation. Finally, one should always be aware that treatment plants have to be composed according to local conditions. Depending on the amount and composition of wastes, an integration of tool has to be found that not only meets the demands stemming from the wastewaters but also can be integrated into the existing economical and ecological frame