Purpose: This paper aims to elucidate urban development-induced processes affecting the sediment and the distribution of contaminating metals in a seasonal pond located in the highly populated Israeli Coastal Plain. The paper demonstrates how an integrated approach, including geochemical, sedimentological, geochronological, mathematical, historical, and geographical analyses, may decipher a complicated and dynamic metal pollution history in a sedimentary environment controlled by anthropogenic activity. Materials and methods: Three short sediment cores were collected from the margins and center of a small urban pond (Dora, Netanya), located within the Israeli Coastal Plain. Profiles of grain size, organic matter (OM), trace metals (Pb, Zn, V, Ni, Cu, Cr and Co), Pb isotopic ratios, and 210Pb activities (center and southern cores) were determined and a geochemical mixing model was employed (southern core). The watershed contour was calculated, and aerial photos and satellite images were examined. Results and discussion: Construction activities in the watershed were chronologically associated with coarse sediment transport and deposition in the margins of the pond. The upper sandy layers were superimposed on layers rich in fine particles and OM, high concentrations of trace metals, and with Pb isotopic composition of more recent petrol. In the 210Pb-dated southern core, deep metal-rich layers with petrol-related Pb isotopic ratios were inconsistent with metal emissions history. These findings point to mobility and migration of recent contamination metals through the coarse upper sediment layers and into deeper denser layers, confirmed also by a geochemical mixing model. Conversely, in the center of the pond, homogeneous fine particles were deposited with metal profiles consistent with regional emissions. Conclusions: A small urban pond was found to provide an important case study for understanding heavy metal pollution records in highly populated regions. The margins of the pond depicted the surrounding urban development and the induced coarse sediment erosion, accompanied with post-depositional metal mobility. Due to the proximate developing residential areas, high metal concentrations accumulated in the margins, overshadowing regional atmospheric pollution levels recorded by sediment at the center of the pond.
Bibliographical noteFunding Information:
We thank the anonymous reviewers for their helpful comments. We are very thankful to many people who helped in performing this research: the staff of the Geological Survey of Israel, Toplyakov Nataly and Yoffe Olga for laboratory help and Ashkenazi Shlomo, Kitin Michael, Lutzky Hallel, and Mizrahi Yaakov for fieldwork; Nimer Taha from the University of Haifa for laboratory support; Wim Boer and Piet van Gaever from the Royal Netherlands Institute for Sea research (NIOZ) for Pb analysis; Ne’eman Tamar from the Hebrew University for GIS analyses; and Erez Didi from the municipality of Netanya for providing maps of the watershed. We would like to thank the Ministry of National Infrastructure, Energy and Water Resources for funding this research and the University of Haifa for a postdoc fellowship to IZ. 210
© 2017, Springer-Verlag Berlin Heidelberg.
- Anthropogenic impact
- Heavy metals pollution
- Heterogeneous sediment
- Lead isotopes
- Metals mobility
- Urban pond