. . . . . . "Approximately 80 % of our air pollution stems from hydrocarbons released by vegetation, so let's not go overboard in setting and enforcing tough emission standards from man-made sources."@en. "Source: Freebase - The World's database". _:RnTJTKwh1104. _:RnTJTKwh1104 "31180". _:RnTJTKwh1104 .