ORCID

Abstract

The biogeochemistry and bioavailability of cadmium, released during sphalerite weathering in soils, were investigated under contrasting agricultural scenarios to assess health risks associated with sphalerite dust transport to productive soils from mining. Laboratory experiments (365 d) on temperate and sub-tropical soils amended with sphalerite (<63 μm, 0.92 wt.% Cd) showed continuous, slow dissolution (0.6-1.2% y(-1)). Wheat grown in spiked temperate soil accumulated ≈38% (29 μmol kg(-1)) of the liberated Cd, exceeding food safety limits. In contrast, rice grown in flooded sub-tropical soil accumulated far less Cd (0.60 μmol kg(-1)) due to neutral soil pH and Cd bioavailability was possibly also controlled by secondary sulfide formation. The results demonstrate long-term release of Cd to soil porewaters during sphalerite weathering. Under oxic conditions, Cd may be sufficiently bioavailable to contaminate crops destined for human consumption; however flooded rice production limits the impact of sphalerite contamination.

DOI

10.1016/j.envpol.2013.09.001

Publication Date

2014-01-01

Publication Title

Environ Pollut

Volume

184

First Page

283

Last Page

289

Embargo Period

2014-09-01

Organisational Unit

School of Geography, Earth and Environmental Sciences

Keywords

Human health, Metals, Rice, Risk assessment, Sulfide weathering, Agriculture, Cadmium, Mining, Oryza, Soil, Soil Pollutants, Sulfides, Weather, Zinc Compounds

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