SPATIAL AND TEMPORAL DISTRIBUTION OF HEAVY METAL COMPOSITIONS IN URBAN SOILS IN NEW JERSEY (2007-2015)

We have been monitoring surface environmental quality in Jersey City by utilizing urban soils since 2007. Our aim is to generate a comprehensive dataset to elucidate temporal and spatial distribution of heavy metal concentrations in soils, and to evaluate their potential environmental and human health impacts. These datasets are essential in implementing regulations and standards for soil pollution management and remediation specific to Jersey City. Jersey City, the second most populous city in New Jersey, is one of the most contaminated cities in the USA. Top-soil samples from urban parks were systematically collected during summer months and their coordinates were integrated into a GIS. Two sets of soil profiles (O, A and E) from the Boonton Series were also analyzed to establish local background values and variability, which were used to calculate geo-accumulation (Igeo) index to assess the impact of anthropogenic activities.

Special emphasis is placed on particle size distribution (Ro-Tap and Sedigraph) and chemical composition of soil samples using a portable-XRF (NITON XL3t). We report selected heavy metals (As, Cr, Cu, Pb, and Zn) in the fine-size fraction (<63µm). Since 2013, we also collected residential soils, which have noticeably higher levels of heavy metals compared to those of nearby parks. This is particularly valid for Pb concentrations. Considering the fact that 49 % of the houses were constructed prior to 1950, this could be attributed to indoor Pb-paint. However, our preliminary Pb-isotopic data is inconclusive to suggest that Pb-bearing indoor paint is one of the major sources of Pb contamination in residential settings. Furthermore, we have documented that Pb-bearing outdoor paint has limited (< 1 m) impact on overall soil quality in Jersey City. Compared to local background values (Igeo), more than 30 % of urban park soils were extremely contaminated (Igeo >4) with respect to Pb. Extensive urbanization and industrialization has been attributed to prevailing heavy metal contamination in Jersey City soils. Among many anthropogenic sources, traffic volume still plays a significant role controlling the distribution and concentrations of heavy metals, especially Pb, suggesting that resuspension of Pb-bearing fine particulates are the primary environmental and human health concerns.