Polycyclic Aromatic Hydrocarbon - Human Health

Human Health

PAHs toxicity is very structurally dependent, with isomers (PAHs with the same formula and number of rings) varying from being nontoxic to being extremely toxic. Thus, highly carcinogenic PAHs may be small or large. One PAH compound, benzopyrene, is notable for being the first chemical carcinogen to be discovered (and is one of many carcinogens found in cigarette smoke). The EPA has classified seven PAH compounds as probable human carcinogens: benzanthracene, benzopyrene, benzofluoranthene, benzofluoranthene, chrysene, dibenz(a,h)anthracene, and indeno(1,2,3-cd)pyrene.

PAHs known for their carcinogenic, mutagenic and teratogenic properties are benzanthracene and chrysene, benzofluoranthene, benzofluoranthene, benzofluoranthene, benzopyrene, benzoperylene, coronene, dibenz(a,h)anthracene (C₂₀H₁₄), indeno(1,2,3-cd)pyrene (C₂₂H₁₂) and ovalene.

High prenatal exposure to PAH is associated with lower IQ and childhood asthma. The Center for Children's Environmental Health reports studies that demonstrate that exposure to PAH pollution during pregnancy is related to adverse birth outcomes including low birth weight, premature delivery, and heart malformations. Cord blood of exposed babies shows DNA damage that has been linked to cancer. Follow-up studies show a higher level of developmental delays at age three, lower scores on IQ tests and increased behaviorial problems at ages six and eight.

In addition, a 2012 Columbia University study in Environmental Health Perspectives linked prenatal exposure to pollutants and eventual child behavioral outcomes. The study found that exposure to higher levels of PAH was associated with a 24% higher score of anxiety/depression for children ages 6 to 7 than those with low exposure levels. Infants found to have elevated PAH levels in their umbilical cord blood were 46% more likely to eventually score highly on the anxiety/depression scale than those with low PAH levels in cord blood.