Dibenz 'a'',''j''nthracene or Benzo etraphene or 1,2:7,8-Dibenzanthracene is an organic compound with the

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

C₂₂H₁₄. It belongs to the class of polycyclic aromatic hydrocarbons (PAHs) and is formed whenever there is incomplete combustion of organic matter. The IARC (International Agency for Research on Cancer) has classified it as ''possibly

carcinogenic A carcinogen () is any agent that promotes the development of cancer. Carcinogens can include synthetic chemicals, naturally occurring substances, physical agents such as ionizing and non-ionizing radiation, and Biological agent, biologic agent ...

'' to humans, grouped into IARC group 2B.

Description

Dibenz(a,j)anthracene is a

polycyclic aromatic hydrocarbon A Polycyclic aromatic hydrocarbon (PAH) is any member of a class of organic compounds that is composed of multiple fused aromatic rings. Most are produced by the incomplete combustion of organic matter— by engine exhaust fumes, tobacco, incine ...

with five

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

rings. It has low water solubility and low volatility and therefore occurs predominantly in solid form, bound to particulates in polluted air, soil, or sediment.

Occurrence

Dibenz(a,j)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 Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It is a type of creosote. It has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psoria ...

distillation, or within engine exhaust. On a personal level it is produced with high temperature cooking like

frying Frying is the cooking of food in cooking oil, oil or another fat. Similar to sautéing, pan-fried foods are generally turned over once or twice during cooking to make sure that the food is evenly cooked, using tongs or a spatula, whilst sautéed ...

grilling Grilling is a form of cooking that involves heat applied to the surface of food, commonly from above, below or from the side. Grilling usually involves a significant amount of direct, radiant heat, and tends to be used for cooking meat and v ...

, broiling,

roasting Roasting is a cooking method that uses dry heat where hot air covers the food, cooking it evenly on all sides with temperatures of at least from an open flame, oven, or other heat source. Roasting can enhance the flavor through caramelizat ...

and baking, but also when

cigarette smoking Tobacco smoking is the practice of burning tobacco and ingesting the resulting smoke. The smoke may be inhaled, as is done with cigarettes, or released from the mouth, as is generally done with pipes and cigars. The practice is believed to hav ...

or marijuana smoking.

Health effects

As of 2010, the IARC (International Agency for Research on Cancer) has classified dibenz(a,j)anthracene as ''possibly

'' to humans, grouped into IARC group 2B. No epidemiological studies on human exposure to dibenz(a,j)anthracene as an individual PAH exist, because PAHs always occur as components of complex chemical mixtures and never occur in isolation in the environment. PAHs all have a similar mechanism of causing cancer in both humans and experimental animals whereby they are metabolically converted to oxides and dihydrodiols, and then oxidized to diol epoxides, which react with

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

, inducing mutations.

In space

In February 2014,

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

announced a database for tracking polycyclic aromatic hydrocarbons (PAHs), including dibenz 'a'',''j''nthracene, in the

universe The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from s ...

. According to scientists, more than 20% of the

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

in the universe may be associated with PAHs, possible starting materials for the formation of

life Life, also known as biota, refers to matter that has biological processes, such as Cell signaling, signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, Structure#Biological, organisation, met ...

. PAHs seem to have been formed shortly after the

Big Bang The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models based on the Big Bang concept explain a broad range of phenomena, including th ...

, are widespread throughout the universe, and are associated with new stars and

exoplanets An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detec ...

References

Polycyclic aromatic hydrocarbons IARC Group 3 carcinogens {{hydrocarbon-stub

Description

Occurrence

Health effects

In space

See also

References