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Polycyclic aromatic hydrocarbons (PAHs) (four indicator compounds of LRTAP)

PAHs, benzo[a]pyrene, benzo[b]fluoranthrene, benzo[k]fluranthrene, indo[1,2,3-cd]pyrene.

SPRI Emission Reporting Threshold
1.00 Kg/yr Pollutant Emissions to Water
1.00 Kg/yr Pollutant Emissions to Waste Water
5.00 Kg/yr Pollutant Emissions to Land
1.00 Kg/yr Pollutant Emissions to Air
Disclaimer
This sheet is a generic summary, designed to give the reader a basic level of background information about the substance in question. Great care has been taken to represent as effectively and correctly as possible the broad range of (not necessarily consistent) information which is available from a variety of sources. The reader must accept therefore that this sheet has no legal status and cannot be relied upon in any legal proceedings. SEPA disclaims any responsibility or liability whatsoever for errors and omissions in this sheet.
What is it?
Polycyclic aromatic hydrocarbons (PAHs) are a very large group of chemicals. Pure PAHs are crystalline solids, but they are rarely found in this form outside the laboratory. In the environment, they are usually absorbed onto soot particles.
What is it used for?
Other than for research and analytical purposes, PAHs do not have any use and are not intentionally manufactured for other purposes.
Where does it come from?
The biggest source of PAHs are combustion processes (industrial, domestic and transport). Cigarette smoke contains small amounts. They also occur in mineral oils, tars, creosote, carbon black and pitch. They are released naturally from forest fires.
How might it affect the environment?
Emissions of PAHs may affect local wildlife (causing cancer, birth defects and mututations). They can also be carried long distances in the atmosphere (usually bound to soot particles) and so may also affect wildlife far from where they were released.
How might exposure to it affect human health?
Polycyclic Aromatic Hydrocarbons (PAH) are a mixture of compounds which can enter the body either by inhalation of contaminated air, ingestion of contaminated food or water, or by dermal contact with soil or water contaminated with PAH. Inhalation of PAH, and the associated health effects in humans, is not clearly understood, although animal studies have shown that the inhalation of high levels of PAH for long periods of time has resulted in tumour development. Ingestion of PAH, and the associated health effects in humans, is not clearly understood, although animal studies have shown that the ingestion of high levels of PAH for long periods of time has resulted in tumour development. Dermal contact with PAH, and the associated health effects in humans, is not clearly understood, although animal studies have shown that skin contact with high levels of PAH for long periods of time has resulted in tumour development. The International Agency for Research on Cancer has designated some polycyclic aromatic hydrocarbons as probable carcinogens. However, exposure to polycyclic aromatic hydrocarbons at normal background levels is unlikely to have any adverse effect on human health.
What steps are being taken to limit the potential impacts?
UK (including Scottish) releases of PAHs are controlled under the surface water pollution prevention and control (PPC) regulations; the European Air Quality Framework Directive (96/62/EC); and the Water Framework Directive. The UK is also a signatory to the UNECE Convention on Long-Range Transboundary Air Pollutants (LRTAP) which includes a protocol to develop a legally binding global agreement to reduce risks to health and the environment posed by persistent organic pollutants (POPs) such as PAHs. PAHs are also listed as "priority action" substances under the the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) and the Helsinki Convention which protects the marine environment of the Baltic sea.