THE ENVIRONMENTAL EFFECTS OF FREIGHT

include benzene (a known carcinogen), toluene, polynuclear aromatic hydrocarbons, formaldehyde, cyanide, hydrogen sulphide, dioxin, and so on (Kürer pp. 485-6). Either because most governments do not yet regulate these emissions, or because much less is known about their impacts (the second point may

  Aromatic, Polynuclear, Polynuclear aromatic