Impact of highway traffic and the acoustic screen on the content and spatial distribution of heavy metals in soils

Szymon Różański,Joanna Nowak,Hanna Jaworska,Amber Hardy,Katarzyna Matuszczak

doi:10.1007/s11356-017-8910-z

Abstract

Recent years have witnessed intensification of road traffic and, with it, the amount of substances emitted by vehicles. Such emissions need to be monitored for public health purposes. The aim of this study was to evaluate the impact of the highway traffic on the total content and bioavailability of Zn, Cu, Ni, Cd, Cr and Pb in nearby soils as well as influence of an acoustic screen on spatial distribution of the metals. The material included 40 soil samples collected from 15 research points located 5, 10, 25 and 50 m away from the road acoustic screen and from 4 points between the screen and the highway. Additionally, 5 research points were located next to the metal barrier. Selected physicochemical properties of soils were determined: soil texture, soil pH, TOC and CaCO3 content. The total content of heavy metals in the soils was determined by AAS after digestion in aqua regia and bioavailable forms in 1 M diethylenetriaminepentaacetic acid. The research found low impact of the highway traffic on the content of heavy metals in soils; however, due to a very short period of this potential impact (5 years), the moderately polluted category of geo-accumulation index of cadmium and high bioavailability of lead indicate the need of repeating the research within the next several years. Furthermore, the road acoustic screen significantly influenced spatial distribution of the metals in soils.

Highlights

The rise of mechanized transportation is associated with the development of road infrastructure
The aim of this study was to evaluate the impact of traffic in the vicinity of an acoustic screen on the spatial distribution of zinc (Zn), copper (Cu), nickel (Ni), cadmium (Cd), chromium (Cr) and lead (Pb) in soils intensively cultivated for food production after 5 years of highway running
The highest total content of heavy metals in analysed soils was seen in zinc (18.40–46.53 mg kg−1) and chromium (15.98–31.88 mg kg−1)

Summary

Introduction

The rise of mechanized transportation is associated with the development of road infrastructure. Road traffic is a major source of substances in the soil and atmosphere (Pallavi and Harrison 2013), including, among others, heavy metal compounds (Johanssona et al 2009). The content of certain compounds in the soil is directly proportional to vehicle speed. Higher vehicle velocity causes increased emissions of exhaust containing, among other compounds, heavy metals (Duong and Lee 2011). The content of heavy metals in soil may be affected by natural (climate, soil processes) and anthropogenic factors such as agriculture and road traffic (Wei et al 2007). The content of heavy metals in soils located along roads is strongly related to traffic and decreases with increasing distance from the road (Temmerman et al 2003)

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