Exploring the impact of transportation on heavy metal pollution: A comparative study of trains and cars

Abstract

This study aimed to investigate the impact of road and rail traffic on the soil through the analysisof the presence of heavy metals in soil samples collected next to a busy highway, local roads, andnext to an active railway line. Results showed that cars emitted higher levels of heavy metals thantrains. Soil samples near the highway had higher levels of Cu, Ni, and Hg. The values of thecalculated indices like geo-accumulation index, potential toxicity response index, ecological riskfactor, contamination factor, pollution load index, Nemerow’s pollution index, and degree ofcontamination confirm that the soil samples sampled near the highway are the most polluted andhighway have the greatest negative impact on the soil environment. These results suggest thatcontrolling car emissions through strict regulations and promoting public transportation couldeffectively reduce the heavy metal concentrations in soil, particularly from highway emissions.