Polycyclic aromatic hydrocarbons
Polycyclic aromatic hydrocarbons (PAHs) are a large group of chemicals including naphthalene, acenaphthene, anthrocene, triphenylene, phenantrene, benzapyrene, benzofurane and fluoroantene.
They are emitted when petrol, coal, waste, tobacco, some incenses and grilled meat are burned. They are also used in industry to make products such as plastics, wood preservatives, resins, colourings, pipe cladding, medicines etc.
In the home, as well as from outside, PAHs can be found in heaters, fireplaces and chimneys, candles, incense and tobacco.
Creosote is a greatly used product which contains dozens of these compounds. It is widely used in wood preservatives, for example. The EU has adopted certain measures to limit and completely eliminate some of its uses e.g. in enclosed spaces. It is also used in products which treat illnesses such as psoriasis.
One of the most common aromatic hydrocarbons in creosote is naphthalene.
Naphthalene is, amongst other things, the raw material used in the synthesis of phthalates, synthetic resins and concrete plasticisers, and is also used in the production of plasterboards, synthetic rubbers, paints and the insecticide carbaryl.
According to WHO, naphthalene is concentrated inside buildings due to the use of certain consumer products e.g. multipurpose solvents, lubricants, coal burners, hairsprays, kerosene lamps (especially in areas of poor ventilation), rubber materials and, particularly for naphthalene, in mothballs and toilet disinfectants (although this has decreased considerably in Western Europe).
Several PAHs are known to be carcinogenic, mutagenic and teratogenic. Prenatal exposure to them has been linked to premature births, low birth weight, congenital cardiac defects, lower IQ, delayed development, behavioural changes, anxiety or depression, and childhood asthma. The database from The Collaborative on Health and The Environment has also associated these chemicals with cancer (bladder, throat, lung, breast, esophagus, nasopharyngeal, pancreas, prostate, kidney, testicular etc.), porphyria, immunosuppression, photosensitivity, adult leukaemia, bone cancer, colorectal cancer, coronary diseases, early menopause, melanoma, oral cancer, reduced male fertility, stomach cancer etc.