Total petroleum hydrocarbons and trace heavy metals in roadside soils along the Lagos-Badagry expressway, Nigeria.

This study reports the level of total petroleum hydrocarbons (TPH) and trace heavy metals (lead, copper, and cadmium) in soil samples collected randomly from Iyana-Iba garage, Lagos State University bus stop, Adeniran Ogunsanya College of Education bus stop, and a control site off Lusada-Atan road, near Crawford University, Igbesa, Ogun state. TPH was estimated gravimetrically after Soxhlet extraction and column clean up, while soil metals were determined by atomic absorption spectrometry using mineral acid digestion. For TPH, the sites have mean values of 19.