PAHs

Polycyclic Aromatic Hydrocarbons (PAHs) are a subfamily of aromatic hydrocarbons, i.e. molecules consisting of carbon atoms and hydrogen.

PAHs have been extensively studied for many years because they are compounds present in all environmental media that show high toxicity.

Frequently used within road structures made from coal, these hydrocarbons must be recycled according to precise, regulated and often expensive processes. Not being harmful when "trapped" in the road structure, it is preferable - as often as possible - not to evacuate the structural layers being contaminated with PAH.

One of the reasons for the classification of PAHs in the EPA's list of priority pollutants is the toxic nature of some of them. They are biologically active molecules which, once absorbed by organisms, lend themselves to transformation reactions under the action of enzymes leading to the formation of epoxides and/or hydroxy derivatives.

The metabolites thus formed can have a more or less marked toxic effect by binding to fundamental biological molecules such as proteins, RNA, DNA and cause cellular dysfunctions.

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