Roadside dust samples were collected from selected
areas near the fuel stations in Karkh District of Baghdad
City, the capital of Iraq, as well as both sides of the highway
between Ramadi and Rutba. In order to assess the probable
pollution level of heavy metals (Cd, Ni, and Pb) in the study
areas, they were determined in the roadside dust using an
atomic absorption spectrophotometer. The extent of traffic
contribution to roadside dust was assessed by comparing the
metal concentrations in roadside dust to those of Upper Continental
Crust background considering a Cd background of
0.098 mg/km, Ni background of 44 mg/km, and Pb background
of 16 mg/km using geo-accumulation index (I geo),
contamination factor (CF), and pollution load index (PLI).
The roadside dust contains relatively elevated levels of heavy
metals. The average concentration of Cd, Ni, and Pb in Baghdad
is 0.17, 25.5, and 14.8 mg/kg; in the north of the highway
is 0.14, 23.4, and 14.7 mg/kg; and in the south of the highway
is 0.2, 27.4, and 15.6 mg/km. The higher averages of these
metals were recorded in the south of the highway. The study
areas are impacted with considerable quantity of metals. The
distribution pattern of the concentrations of metals was essentially
affected by exhausted gases emitted from transportation
automobile where the direction of the prevailing wind played
a major role in the transport of the pollutants, causing an
increase in metal concentrations towards the south side of
the highway.