21.   Benzene is an aromatic hydrocarbon found in gasoline and other fuels.

22.   Benzene is an aromatic hydrocarbon found in gasoline, diesel and other fuels.

23.   During a normal work day, barehanded workers handle toxic heavy metals, potentially cancer-causing polycyclic aromatic hydrocarbons and asbestos.

24.   He and most astronomers favor a family of complex carbon-based molecules, known as polycyclic aromatic hydrocarbons, as the cause of the DIBs.

25.   The researchers said the Allan Hills meteorite contained organic molecules called polycyclic aromatic hydrocarbons, or PAHs, that can be associated with life processes.

26.   Then they looked at PAHs, or polycyclic aromatic hydrocarbons, produced by the burning of fossil fuels.

27.   The McMaster report says the evidence shows the mutation of the nestling gulls can be attributed to toxins called polycyclic aromatic hydrocarbons, or PAHs.