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Polycyclic Aromatic Hydrocarbons (PAHs)

What are they?

Polycyclic aromatic hydrocarbons (PAHs) are a group of more than 100 chemicals that are also called polynuclear aromatic hydrocarbons. 

PAHs are released from burning coal, oil, gasoline, trash, tobacco, and wood. High-temperature cooking, such as grilling, will form PAHs in meat and other foods. Manufactured PAHs may be used in medicines and pesticides.

PAHs can be released naturally from forest fires and volcanoes.

See also: Construction Factories Food and Cooking Air Pollution Agriculture Mines Cancer

Where are Polycyclic Aromatic Hydrocarbons (PAHs) found?

  • Air – cigarette and secondhand smoke, vehicle exhaust, and emissions from fossil fuels, forest fires, and volcanoes
  • Food – grilled meats
  • Water – contaminated by emissions

How can I be exposed to Polycyclic Aromatic Hydrocarbons (PAHs)?

Polycyclic Aromatic Hydrocarbons (PAHs) commonly enter(s) the body through:

Ingestion (swallowing)
  • Eating grilled, charred, charcoal broiled, or contaminated meats or foods; drinking contaminated water or milk
Inhalation (breathing)
  • Smoking cigarettes; breathing cigarette or secondhand smoke, vehicle exhaust, fumes from asphalt, or emissions from fossil fuels, fires, and volcanoes
Skin contact
  • Touching food that contains PAHs

What happens when I am exposed to Polycyclic Aromatic Hydrocarbons (PAHs)?

Exposure to some PAHs can cause:

  • Irritation of the eyes and breathing passages
  • Cancer

Who is at risk for exposure to Polycyclic Aromatic Hydrocarbons (PAHs)?

  • Consumers
    • Grilled or charred foods, water, and milk may contain PAHs.
  • Cigarette smokers
    • Cigarette and secondhand smoke contain PAHs.
  • Infants
    • Breast milk can contain low levels of PAHs in those living near hazardous waste sites.

Reduce your risk

If you think your health has been affected by exposure to PAH's, contact your health care professional. 

Always wash your hands thoroughly after handling chemicals. For poisoning emergencies or questions about possible poisons, please contact your local poison control center at 1-800-222-1222.

  • Do you, or does anyone in your household, smoke tobacco products?
  • How frequently are you exposed to vehicle exhaust or gas stations?
  • Do you live near a busy highway?
  • Are you routinely exposed to wood smoke or other products that have been burned?
  • Do you eat grilled or charred meats?
  • Do you use well water?
  • Do you use pesticides made with PAHs?
  • Are you exposed to wildfires or wood fires?
  • If you smoke, quit. Avoid secondhand smoke.
  • Limit your time near idling cars, trucks, or buses.
  • If you are exposed to wildfires, wear a mask.
  • Routinely test well water for PAHs. 
  • If your well water has high levels of PAHs, contact your local or state health agency or the Centers for Disease Control and Prevention (CDC) for information on how to reduce your exposure.
  • If your well water contains PAH levels above EPA’s drinking water advisory levels, consider using bottled water for drinking and cooking or install an activated carbon filtration system or reverse osmosis system.
  • Read labels when applying pesticides, and follow the directions.
  • Limit the amount of grilled foods you eat.
  • Avoid asphalt roads that are being repaved.
  • Don’t let children play in the dirt near areas where coal, wood, gasoline, or other products have been burned.
  • Don’t let children play in dirt near waste sites or factories.
  • Don’t let children play near gas stations, idling cars, or busy highways.
National Library of Medicine Resources and Databases
Additional Resources
  • Polycyclic Aromatic Hydrocarbons. ToxFAQs (Agency for Toxic Substances and Disease Registry)

    Factsheet with answers to the most frequently asked questions about polycyclic aromatic hydrocarbons (PAHs) exposure and their effect on human health, developed by a federal public health agency that protects communities from harmful health effects related to exposure to natural and man-made hazardous substances.

  • Polycyclic Aromatic Hydrocarbons (PAHs) (Centers for Disease Control and Prevention)

    Resource on Polycyclic Aromatic Hydrocarbons (PAHs), including information on exposure, health effects, levels of PAH metabolites in the US population, and links to additional resources.

  • Polycyclic Aromatic Hydrocarbons (PAHs) Factsheet (State of California)

    Factsheet on polycyclic aromatic hydrocarbons (PAHs) that includes information on sources, possible health concerns, and ways to reduce exposure.

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