Polycyclic aromatic hydrocarbon

A Polycyclic aromatic hydrocarbon (PAH) is any member of a class of <a href="/facts/Organic_compound/gqCNaN45">organic compounds</a> that is composed of multiple <a href="/facts/Aromatic_ring/wK0DzRY6">aromatic rings</a>. Most are produced by the incomplete combustion of <a href="/facts/Organic_matter/t17tVCvk">organic matter</a>— by engine exhaust fumes, tobacco, incinerators, in roasted meats and cereals, or when biomass burns at lower temperatures as in <a href="/facts/Forest_fires/LU3797A0">forest fires</a>. The simplest representative is <a href="/facts/Naphthalene/RU2sV8mN">naphthalene</a>, having two aromatic rings, and the three-ring compounds <a href="/facts/Anthracene/mV8Sblcq">anthracene</a> and <a href="/facts/Phenanthrene/tE9YALIM">phenanthrene</a>. PAHs are uncharged, non-polar and planar. Many are colorless. Many of them are also found in fossil fuel deposits such as <a href="/facts/Coal/83kV3qxg">coal</a> and in <a href="/facts/Petroleum/IQV0bHVd">petroleum</a>. Exposure to PAHs can lead to different types of <a href="/facts/Cancer/PVW6n1D0">cancer</a>, to <a href="/facts/Fetal_development/VpV3S4lu">fetal development</a> complications, and to <a href="/facts/Cardiovascular/WXwudzzc">cardiovascular</a> issues.[medical citation needed]
Polycyclic aromatic hydrocarbons are discussed as possible <a href="/facts/PAH_world_hypothesis/lf05Xq1R">starting materials</a> for <a href="/facts/Abiotic/CA3Dwtta">abiotic</a> syntheses of <a href="/facts/Material/Rmt5HySL">materials</a> required by the <a href="/facts/Abiogenesis/BvAmLPQP">earliest forms of life</a>.

Polycyclic aromatic hydrocarbon open-in-new

Polycyclic aromatic hydrocarbon