Trace element contamination of soil and dust by a New Caledonian ferronickel smelter: Dispersal, enrichment, and human health risk

K L Fry; M M Gillings; C F Isley; P Gunkel-Grillon; Mark Patrick Taylor

doi:10.1016/j.envpol.2021.117593

Trace element contamination of soil and dust by a New Caledonian ferronickel smelter: Dispersal, enrichment, and human health risk

Environ Pollut. 2021 Nov 1:288:117593. doi: 10.1016/j.envpol.2021.117593. Epub 2021 Jun 28.

Authors

K L Fry¹, M M Gillings², C F Isley², P Gunkel-Grillon³, Mark Patrick Taylor⁴

Affiliations

¹ Earth and Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, 2109, New South Wales, Australia. Electronic address: kara.fry@mq.edu.au.
² Earth and Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, 2109, New South Wales, Australia.
³ Institute of Exact and Applied Sciences (ISEA), University of New Caledonia, BPR4 98851 Nouméa Cedex, New Caledonia, France.
⁴ Earth and Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, 2109, New South Wales, Australia. Electronic address: mark.taylor@mq.edu.au.

PMID: 34245983
DOI: 10.1016/j.envpol.2021.117593

Abstract

Metallurgical industries remain a considerable source of trace element contamination and potential human health risk. Determination of sources is a key challenge. With respect to the South Pacific's largest and longest operating metallurgic smelter in Nouméa, New Caledonia, determining the environmental impact and subsequent human health risk associated with local ferronickel smelting is complicated by natural geological enrichment of Ni and Cr. This study applies a multi-method and multi-matrix approach to disentangle smelter emissions from geogenic sources and model the consequent health risk from industrial activity. Dust wipes (n = 108), roadside soil (n = 91), garden soil (n = 15) and household vacuum dust (n = 39) were assessed to explore geospatial trace element (As, Cr, Cu, Fe, Mn, Ni, Pb, S, V and Zn) variations across outdoor and indoor environments. Enrichment factors (EF) identified elevated levels of smelter-related trace elements: S (EF = 7), Ni (EF = 6) and Cr (EF = 4), as well as Zn (EF = 4). Smelter-related elements in soil and dust deposits were negatively correlated with distance from the facility. Similarity of Pb isotopic compositions between dust wipes, surface soil and vacuum dust indicated that potentially toxic trace elements are being tracked into homes. Non-carcinogenic health risk modelling (Hazard Index, HI) based on 15 spatial nodes across Nouméa revealed widespread exceedance of tolerable risk for children (0-2 years) for Ni (HI 1.3-15.8) and Mn (HI 0.6-1.8). Risk was greatest near the smelter and to the north-west, in the direction of prevailing wind. Given the elevated cancer risk documented in New Caledonia, disentanglement of environmental from industrial sources warrants further attention to ensure community health protection. Our analysis illustrates how the confounding effects from complex environmental factors can be distilled to improve the accuracy of point source apportionment to direct future mitigation strategies.

Keywords: Chromium; Ferronickel smelting; Human health risk; Nickel; Pacific islands.

MeSH terms

Child
Dust / analysis
Environmental Monitoring
Humans
Iron
Metallurgy
Metals, Heavy* / analysis
Nickel
Risk Assessment
Soil
Trace Elements* / analysis

Substances

Dust
Metals, Heavy
Soil
Trace Elements
ferronickel
Nickel
Iron