Benzo(a)pyrene, a Polycylic Aromatic Hydrocarbon

Benzo(a)pyrene, or B(a)P, belongs to a group of compounds called polycyclic aromatic hydrocarbons (PAH) that are commonly found in airborne mixtures of pollution, like soot. B(a)P is a known carcinogen as well as a suspected developmental, hormone, liver, respiratory, skin, and immune system toxicant ^[1]. B(a)P is a persistent bioaccumulative toxin, which means it is toxic, persists in the environment and bioaccumulates in food chains.

Recent studies indicate that exposure to benzo(a)pyrene in utero can have negative consequences for fetal development, specifically causing a higher chance of cancer later in life ^[2]. Recent evidence also indicates lower birthweights and head size as a result of exposure to B(a)P ^[3]. Mice that were fed high levels of one PAH during pregnancy had difficulty reproducing, as did their offspring. These offspring also had higher rates of birth defects and lower body weights ^[4].

Benzo(a)pyrene results from incomplete burning of organic materials in industrial processes, transportation, energy production and use, food preparation, tobacco, trash burning, and wildfires. People are exposed to B(a)P primarily by breathing air containing the pollutant and secondarily by drinking water, touching materials, and eating food containing the compound. Small amounts of B(a)P can also be found in charcoal-broiled food, roasted coffee, fruits and vegetables ^[4]. The majority of B(a)P emissions in Oregon are from sources such as vehicle exhaust, forest fires, wood stoves, and backyard burning. Backyard burning is still common in many parts of the state.

Industrial sources are small but significant contributors to B(a)P emissions and include aluminum smelters, steel mills, wood preservers using creosote, and tar/asphalt production.

Public policy solutions that will protect us all:

• Promote alternatives to prescribed and slash burning.
• Promote the use of cleaner or alternative fuels in motor vehicle engines.
• Encourage the retirement of old wood stoves and switching to cleaner burning fuels such as natural gas or wind-derived electricity.
• Create incentives to retrofit off-road engines with pollution control equipment.
• Encourage Oregonians to drive less.
• Ban backyard burning.
• Fully implement Oregon’s executive order phasing out the discharge of persistent bioaccumulative toxins in Oregon by 2020.
  

What you can do to protect yourself:

• When you’re in the market for a new car, purchase a super ultra low emission vehicle (SULEV) or partial zero emission vehicle (PZEV). All vehicles have a label under-the-hood that identifies the emission standard.
• If you have a wood stove, switch to a cleaner burning source of heat such as natural gas or wind-derived electricity. If you must stay with the wood stove, use clean burning wood varieties.
• When grilling, try to avoid blackening your food.

^{[1] Environmental Defense “Scorecard”, Chemical Profile for benzo(a)pyrene (CAS Number: 50-32-8)
[2] Perera, Frederica et al, Biomarkers in Maternal and Newborn Blood Indicate Heightened Fetal Susceptibility to Procardinogenic DNA Damage. Environmental Health Perspectives Vol 112, Number 10, July 2004
[3] Perera, Frederica et al, Molecular Evidence of an Interaction Between Prenatal Environmental Exposures and Birth Outcomes in a Multiethnic Population. Environmental Health Perspectives Vol 112, Number 5, April 2004
[4] Agency for Toxic Substances & Disease Registry, ToxFaqs for Polycyclic Aromatic Hydrocarbons, 1996}