Identification of pollution sources in roadside soils of Cairo-Alexandria Highway, Egypt

Nile Delta represents 63% of Egypt’s fertile agricultural land. Unfortunately, food chain contamination with potentially toxic elements (PTEs) was recorded along Cairo- Alexandria Highway within Nile Delta. This paper aims to identify pollution sources of PTEs (Cd, Pb, Co, Ni, Zn, Cu, Cr, and Mn), using multivariate statistics. Generally, the studied soil is alkaline loam with about3.69% CaCO3and 1.97% organic matter. Pollution levels varied widely from uncontaminated to highly contaminated soil. Cd,Pb, Co, and Ni showed spatial variability, relatively high enrichment, reflecting their anthropogenic sources. Mn and Cr show more uniform distribution, reflecting their natural source from the geologic parent material of Egyptian soil. Surprisingly, no significant road traffic impact was observed at the sampling sites. Multivariate analysis indicates P-fertilizer is the main pollution source rather than traffic in roadside soils. The prevailing of fertilizers as a pollution source may be referred to the expansion in the use of unleaded fuel and the continuous increase in the annual fertilization rate.