DOI: 10.5061/dryad.v6wwpzh93
title: Urban land use impact on soil heavy metal levelsin Lafayette, Louisiana

description: Urban soils can accumulate metal(loid)s from past and current human
 activities, yet data from mid-sized U.S. cities remain limited. The study
 aims to comprehensively map and analyze soil contamination, understand its
 socioeconomic impacts. The ultimate goal is to equip the community with
 critical data to mitigate heavy metal exposure and inform future urban
 planning and public health policies. This dataset reports concentrations
 of As, Cr, Cu, Mn, Ni, Pb, and Zn measured in 1,290 composite topsoil
 samples (0–2.5 cm) from five land uses in Lafayette, Louisiana (USA). This
 study provides critical insights into the distribution of heavy metals in
 urban settings, emphasizing the need for preventative measures and
 targeted interventions to mitigate exposure risks. The comprehensive
 mapping and analysis of soil contamination in Lafayette, LA, serve as a
 model for addressing similar issues in other urban areas, contributing to
 the broader understanding of environmental justice and public health.
description: Between 2021 and 2023, we collected 1,290 composite topsoil
 samples from 24 selected census tracts within Lafayette, Louisiana (USA).
 The goal was to comprehensively map soil heavy metal(loid) contamination
 and understand its health and socioeconomic impacts. Samples were
 collected from both public and residential areas, including high-traffic
 roadways, industrial zones, parks, and residential regions near house
 foundations, street sides, open spaces, and gardens. Typically, one
 representative sample with five subsamples was collected. In residential
 areas, five samples were collected within one meter of house foundations,
 five within one meter of street sides, and five from open spaces. All
 samples were collected from the topsoil layer (0-2.5 cm depth), which is
 the primary zone of contact for children and the layer where heavy metals
 tend to accumulate. Collected soil samples were oven-dried for 24 hours at
 105 degrees Celsius, ground, and sieved through a &lt;2 mm sieve to
 ensure uniformity. Laboratory analysis was performed in the Delta Urban
 Soils Laboratory at the University of Louisiana at Lafayette, utilizing a
 handheld X-ray fluorescence (XRF) analyzer in a benchtop stand (Thermo
 Niton XL3t 955 Ultra). The detection limit of the instrument in the
 Standard Reference Material (SRM) matrix is 8 mg/kg, according to the
 manufacturer (Thermo Scientific, 2024). Measurements resulting in a
 reading of less than the limit of detection were substituted with 8 mg/kg
 for statistical purposes. The soil samples were analyzed in low-density
 polyethylene bags using the XRF for 90 seconds each. Each batch included
 testing SRM reference standards. Results from the XRF analysis for soils
 were compared to U.S. National Institute of Standards and Technology
 (NIST) Standard Reference Materials (SRM) soils: SRM 2710a, SRM 2711a, SRM
 2704, and SRM 2709a. The readings were not adjusted. In the dataset,
 elemental concentrations are reported by census tract to ensure the
 privacy and confidentiality of individual site owners. Values of 0 in the
 columns represent measurements below the detection limit of the XRF
 instrument.
description: # Urban land use impact on soil heavy metal levelsin Lafayette, Louisiana
 Dataset DOI:
 [10.5061/dryad.v6wwpzh93](https://doi.org/10.5061/dryad.v6wwpzh93) ##
 Description of the data and file structure In this file, elemental
 concentrations are reported by census tract to ensure the privacy and
 confidentiality of individual site owners. ## Files and variables ####
 File: Lafayette_soil_heavy_metals_dataset.xlsx **Description:** Sampling:
 composite **topsoil 0–2.5 cm**; 2021–2023; public and private sites across
 the five land-use types. * Preparation/analysis: oven-dried, ground, &lt;2
 mm; measured with pXRF (90 s exposure). * Reporting: values are by
 **census tract** to protect privacy; zeros mark **below detection limit**.
 ##### Variables * **Census tract** — U.S. Census tract ID used to group
 sampling locations (coordinates withheld for privacy). * **Soil sample
 location** — Micro-site context within the tract (e.g., house foundation,
 street side, open space, garden). * **Cr** — Chromium concentration
 (mg/kg), pXRF. * **Mn** — Manganese concentration (mg/kg), pXRF. * **Ni**
 — Nickel concentration (mg/kg), pXRF. * **Cu** — Copper concentration
 (mg/kg), pXRF. * **Zn** — Zinc concentration (mg/kg), pXRF. * **As** —
 Arsenic concentration (mg/kg), pXRF. * **Cd** — Cadmium concentration
 (mg/kg), pXRF; **0** = below instrument detection limit. * **Hg** —
 Mercury concentration (mg/kg), pXRF; **0** = below instrument detection
 limit. * **Pb** — Lead concentration (mg/kg), pXRF.