Heavy Metals Pollution in the Highway – Side Soil around Baghdad City

Abstract

The study aimed to assessment of pollution status by heavy metals Cadmium, Lead, Zinc, and Nickel for Soils in surrounding highway of Baghdad city, evaluate the relation between heavy metals concentration in soil, and study effect of distance from pollution source. Study area was include high express way surrounded Baghdad city, starting from main gate in Yusufiyah and ended in Al-Fedaa Company in 43 km distance approximately. Soil samples were collected from 5 locations with 9 km interval between location and other. Soil Samples were taken from surface layer (0 – 25) cm depth, at both road sides (back and forth) within 4 distances (1.5, 10, 25, and 60 m) from each roads sides, and another samples were taken from 2 km distance from road sides, to comparison 3 samples for same depth.

Results that have been achieved by this study can summarize as following:

1. Results showed that heavy metals concentrations in soil samples along highway which surrounded Baghdad city took the following order

Ni > Zn > Pb > Cd

And all was higher than their concentration in comparison soils.

1. The concentrations of Cadmium were ranged between 0.21– 3.93 mg kg^-1 in soil samples at high way, In general, the concentrations of Cadmium were decreased with distance from road sides, while the higher values were recorded within first and second distances 1.5 and 10 m.
2. The concentrations of Lead were ranged between 36.0 – 129.0 mg kg^-1 in soil samples at high way, while the changes in Lead concentrations in some soil locations was refered to effect of environmental changes, like direction and speed of wind.
3. Zinc concentrations were ranged between 240.0 – 380.0 mg kg^-1 in soil samples at high way, while the increasing of Zinc concentrations in Al-Daura soil samples spite of low traffic jams was due to close located to Al-Daura refinery.
4. Nickel concentrations were ranged between 95.0 – 248.0 mg k^-1 in soil samples at high way, also the concentrations of Nickel were increased in Mohammed Al-Qassim highway soil samples while others heavy metals (Zn, Pb, and Cd) were decreased and this can be attributed to another Nickel source in that location.

Keywords: Pollution, Heavy metals, Soil, Air, Vehicular Traffic, Traffic density, Baghdad. Iraq, AAS