Why is Pak excluded

POLLUTANTS

PAH is a collective name for condensed ring systems, the molecular structure of which consists of several benzene rings. The prototype and best-known representative of this group of carcinogens is 3,4 benzopyrene or benzo (a) pyrene, which is often used as a reference substance for the occurrence of PAHs due to its relatively good traceability. Carcinogenic effects have so far been demonstrated in animal experiments for around fifteen representatives of this class of substances. PAHs are generally formed during pyrolysis processes, especially when wood and other fossil raw materials are burned. The PAHs emitted into the air by combustion processes remain there or are bound to soot particles and can thus get into water, soil and vegetable food through their deposition. They are also produced when smoking food and in considerable quantities when smoking. Another important source in homes are open fireplaces.

Glues containing PAHs (bitumen glue) and wood treated with carbolineum can lead to greatly increased loads. In addition, tarred drinking water pipes were used in the past. Up until the end of the sixties, parquet was glued, among other things, with coal tar pitch dissolved in organic solvents. Mosaic parquet has not been bonded with PAH-containing material since the beginning of the sixties and strip parquet since the end of the sixties. These adhesives have been replaced by synthetic resin adhesives that are not colored black. When laying wooden paving in commercial spaces such as workshops, the use of coal tar-containing adhesives, primers and cardboard was still state of the art for a long time. Since the adhesives are still being produced abroad, current use in Germany cannot be completely ruled out. In addition to the adhesives containing coal tar, bituminous adhesives with very low PAH contents have also been used in rare cases. These adhesives are also black and cannot be distinguished from those containing PAHs by simple tests. In the case of the adhesives used in the above-mentioned periods, however, it can be assumed that there are significant PAH contents. Analyzes of these adhesives show up to 20,000 mg PAH / kg adhesive and more. In polluted apartments, PAHs are found in increased amounts in the house dust.