You've misread the text in that link. The pollution referred to...

  1. 705 Posts.
    You've misread the text in that link.

    The pollution referred to is sulphur dioxide rather than the total pollution your text implies.

    This is not to diminish sulphur dioxide as a pollutant but cars pollute our atmosphere with oxides of nitrogen, carbon dioxide, sooty particulates and metal salts as well as sulphur dioxide.
 
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