Dibenz(a,h)anthracene

Dibenz[a,h]anthracene or Benzo[k]tetraphene or 1,2:5,6-Dibenzanthracene is an organic compound with the chemical formula C22H14. It is a polycyclic aromatic hydrocarbon (PAH) made of five fused benzene rings. It is a fused five-ringed PAH which is common as a pollutant of smoke and oils. It is stable and highly genotoxic in bacterial and mammalian cell systems, as it intercalates into DNA and causes mutations.

Description
Dibenz(a,h)anthracene is a polycyclic aromatic hydrocarbon with five benzene rings. It has low water solubility and low volatility and therefore occurs predominantly in solid form, white to light yellow crystalline, bound to particulates in polluted air, soil, or sediment. It was first synthesized in 1918.

Occurrence
Dibenz(a,h)anthracene is generated whenever organic matter or fuel is incompletely burnt or combusted. Examples include industrial emissions such as coke oven operations in the coal and steel industry, coal tar distillation, or within engine exhaust. On a personal level it is produced with high temperature cooking like frying, grilling, broiling, roasting and baking, but also when cigarette smoking or marijuana smoking.

Health effects
As of 2010, dibenz(a,h)anthracene has been classified as probably carcinogenic to humans, grouped into IARC group 2A. No epidemiological studies on human exposure to dibenz(a,h)anthracene as an individual PAH exists, because PAHs always occur as components of complex chemical mixtures and never occur in isolation in the environment.