“…These heavy metals, particularly lead, have been reported in publications to be almost always present in topsoil and tissues of plants polluted by exhaust from automobiles after fuel combustion in vehicular engines (Gratani et al, 1992;Bahemuka and Mubofu, 1999;Renberg et al, 2000;Yaman et al, 2000;Andrews and Sutherland, 2004;Finster et al, 2004;Yakupoglu et al, 2008;Ikenaka et al, 2010;Aslam et al, 2013). Certain chemical compounds, known to contain lead, were added to gasoline in the past and currently in parts of the world as anti-knocking agent (Wheeler and Rolfe, 1979;Hafen and Brinkmann, 1996;Turer and Maynard, 2003;Iqbal and Shazia, 2004) although, efforts are increasing towards ensuring the reduction in the maximum permitted quantity of lead in fuels (Voegborlo and Chirgawi, 2007). For instance, it was reported that lead content in gasoline was markedly decreased in the United Kingdom after the introduction of the regulations requiring the reduction in the lead content from 0.64 g/l in 1966 to 0.14 g/l in 1986.…”