The effects of urban vehicle traffic on heavy metal contamination in road sweeping waste and bottom sediments of retention tanks

Nicole Nawrot; Ewa Wojciechowska; Shahabaldin Rezania; Jolanta Walkusz-Miotk; Ksenia Pazdro

doi:10.1016/j.scitotenv.2020.141511

The effects of urban vehicle traffic on heavy metal contamination in road sweeping waste and bottom sediments of retention tanks

Sci Total Environ. 2020 Dec 20:749:141511. doi: 10.1016/j.scitotenv.2020.141511. Epub 2020 Aug 4.

Authors

Nicole Nawrot¹, Ewa Wojciechowska², Shahabaldin Rezania³, Jolanta Walkusz-Miotk⁴, Ksenia Pazdro⁴

Affiliations

¹ Gdańsk University of Technology, Faculty of Civil and Environmental Engineering, Narutowicza 11/12, 80-233 Gdańsk, Poland. Electronic address: nicnawro@pg.edu.pl.
² Gdańsk University of Technology, Faculty of Civil and Environmental Engineering, Narutowicza 11/12, 80-233 Gdańsk, Poland.
³ Department of Environment and Energy, Sejong University, Seoul 05006, South Korea.
⁴ Institute of Oceanology of the Polish Academy of Sciences, Marine Geotoxicology Laboratory, Powstańców Warszawy 55, 81-712 Sopot, Poland.

PMID: 32829276
DOI: 10.1016/j.scitotenv.2020.141511

Abstract

Diffuse pollution formed during a surface runoff on paved surfaces is a source of heavy metals (HMs) of various origin. This research study indicates the connection between bottom sediments of retention tanks located on urban streams and road sweeping wastes (RSW) that migrate during surface runoff to the stormwater drainage systems with discharge to the retention tanks. Moreover, we test the primary sources of HMs in RSW by analysing the mechanical wastes (MW) produced by vehicles in order to track the relationship between car parts and HMs deposited in the retention tanks receiving the surface runoff from streets. To identify the origin of HMs diverse source tracking approaches were used: statistical methods, Pb isotope ratios, and the flag element ratio approach. MW presented a very high HMs content (max observed values in mg/kg d.w.: 10477-Zn, 3512-Cu, 412-Pb, 3.35-Cd, 226-Ni, and 633-Cr), while for RSW the HMs content was similar to the bottom sediments. The total carcinogenic risk raises concerns due to the Cr content. The source of Zn was tyre wear and traffic. Ni, Cr, Fe, and Cd were correlated to Zn and shared a common/similar origin. PCA suggested that Cu features quasi-independent behaviour. The Pb isotopic ratios of RSW indicated Pb enrichment originating from coal combustion, while the gasoline and diesel source of Pb was excluded. The Pb isotopic ratios characteristic for MW were in within the following ranges: 1.152-1.165 (²⁰⁶Pb/²⁰⁷Pb), 2.050-2.085 (²⁰⁸Pb/²⁰⁶Pb), and 2.350-2.418 (²⁰⁸Pb/²⁰⁷Pb). The complex analysis of HMs origin confirmed the motorization origin of HMs: Zn, Cr, Ni, and Cd, except Pb (coal combustion as the main source) and Cu (non-uniform origin). The results of various source tracking methods were coherent, but Pb isotope ratios alone brought important information allowing to link Pb in sediments to the atmospheric deposition of coal combustion products.

Keywords: Bottom sediments; Flag element ratio; Pb isotopes; Pollution pathways of heavy metals; Road sweeping waste; Vehicle traffic.