POLYAROMATIC HYDROCARBONS (PAH)

Sources
The polyaromatic (polycyclic) hydrocarbons represent a large group of organic compounds with two or more benzene nuclei. They are slightly soluble in water but readily soluble in fats.
Polyaromatic hydrocarbons are to a greatest extent generated during burning processes, mainly during incomplete burning of coal and diesel oil. Several hundreds of PAHs exist. These compounds are absorbed in the body mainly through the respiratory system, but they can as well get there through water and food.
The carcinogenic effect of 3-,4-benzopyrone (BP) when inhaled is studied best. One of its essential sources is tobacco smoke.

Impact on human health
Inhaled PAHs get absorbed mainly on tar particles and are eliminated through bronchial clearance. The acute, sub-acute and chronic effect of PAHs are poorly studied. More information exists about their mutagenous and carcinogenic effect. It is believed that 9 of 100,000 people, exposed to an average of 1 ng BP as an index, and to the other PAHs in the course of their whole life, will die of lung cancer.
No safety level for PAH content in the atmospheric air may be defined, due to the carcinogenic effect. Different risk levels have been recommended using BP (3-,4-benzopyrone) as an index.
In the USA, for example, it is believed that 9 of 100,000 people, exposed to an average of 1 ng BP in the course of their whole life are at risk of getting lung cancer.

Legislation
Our legislation defines the following limit value (LV) for PAH content in the atmospheric air, in line with Regulation No. 14 (State Gazette No. 88/1997, amended SG No. 46/1999, amended and supplemented, SG No. 8/2002): - 24 hour average LV of 0.1 ยตg/100 m3