Factors controlling the oral bioaccessibility of anthropogenic Pb in polluted soils

Walraven, N.; Bakker, Martine; Os, Bertil van; Klaver, G.; Middelburg, Jack J.; Davies, Gareth R.

doi:10.1016/j.scitotenv.2014.10.118

Cited by 67 publications

(30 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, bioaccessible metal concentrations can be reduced as a result of the formation of precipitates between metal ions and ligands in the gastrointestinal tract. These results lend support to previous research that suggested that the speciation of metals controls metal bioaccessibility (Ruby et al ; Reeder et al ; Scheckel et al ; Walraven et al ). In addition, the present study demonstrated that synchrotron techniques can be useful in risk assessment and contaminated soil remediation.…”

Section: Discussionsupporting

confidence: 90%

Effects of chemical speciation on the bioaccessibility of zinc in spiked and smelter‐affected soils

Elikem

Laird

Hamilton

et al. 2019

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

Previous studies have suggested that understanding soil metal speciation, rather than relying solely on total metal content, can improve the accuracy and utility of contaminated site risk assessments. Because soil properties and reaction time can alter metal speciation, speciation should influence metal bioaccessibility. For example, under gastrointestinal conditions, it is expected that metal species will differ in bioaccessibility depending on their stability in acidic pH environments. We studied the links between metal speciation and bioaccessibility. A combination of synchrotron-based Xray diffraction and X-ray absorption near edge structure (XANES) was used to identify the zinc (Zn) speciation in spiked and smelter-affected soils. After conducting in vitro digestion tests on the soil samples, XANES and linear combination fitting were carried out on the residual pellets to identify the species of Zn that remained after digesting the soils in the simulated gastric and duodenal fluids. The metal species that were not present in the residual pellets were inferred to have been dissolved and, thus, more bioaccessible. Sphalerite (ZnS), ZnO, and outer-sphere Zn contributed more to Zn bioaccessibility than franklinite (ZnFe 2 O 4 ) and Zn incorporated into a hydroxy interlayer mineral (Zn-HIM). The bioaccessibility of Znaluminum layered double hydroxides (Zn-Al-LDH) was found to be inversely proportional to its residence time in soil. It was also observed that the relatively high pH of the duodenum favors metal reprecipitation and readsorption, leading to a reduction in bioaccessible metal concentration. These results imply that metal speciation mainly controls metal bioaccessibility. Environ Toxicol Chem 2019;38:448-459. C 2018 SETAC.

show abstract

Section: Discussionsupporting

confidence: 90%

Effects of chemical speciation on the bioaccessibility of zinc in spiked and smelter‐affected soils

Elikem

Laird

Hamilton

et al. 2019

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

show abstract

“…The Pb bioaccessibilities of the urban garden soils measured here are lower than bioaccessibilites reported for other Pb-contaminated urban and industrial sites (Lamb et al, 2009;Roussel et al, 2010;Sialelli et al, 2011). However, the results are consistent with studies indicating that the high organic matter content of urban garden soils may account in part for low Pb bioaccessibilities (Atkinson et al, 2011;Mao et al, 2014;Walraven et al, 2015). Nevertheless, these same cited studies have also indicated that the original physical-chemical form of the Pb in anthropogenicially contaminated soils maintains a strong residual effect on lability and bioaccessibility of Pb.…”

Section: %supporting

confidence: 82%

Bioaccessibility of As and Pb in orchard and urban soils amended with phosphate, Fe oxide and organic matter

Cai

McBride

et al. 2017

Chemosphere

View full text Add to dashboard Cite

Soils historically contaminated in urban and orchard environments by Pb and As were amended separately with organic matter, soluble Ca phosphate, and Fe oxide to determine whether these materials could lower Pb or As bioaccessibility. After 5 years of equilibration in the laboratory, the amended soils and control were tested for bioaccessibility using the standard physiologically based extraction test (PBET). Bioaccessibilities of Pb and As were not substantially reduced relative to the unamended controls after the 5-year period by any of the soil amendments. Gastric bioaccessibility (GB) of Pb was in all cases much greater than gastrointestinal bioaccessibility (GIB) regardless of soil treatment, whereas GB and GIB of As were similar in magnitude for all soils. Both GB and GIB of Pb were greater in the orchard than the urban soil. Electron microprobe investigations identified discrete particulate forms of Pb in the soils by elemental mapping, and energy dispersive spectrometry (EDS) revealed a frequent spatial association of Pb-rich particles with phosphorus. It is suggested that Pb-rich particles in anthropogenically contaminated soils resist chemical transformation into less labile forms despite thermodynamic favorability because of their low surface area and low solubility. This kinetic effect could explain the observed ineffectiveness of amendments in reducing metal bioaccessibility.

show abstract

“…(Madrid et al, 2008;Sialleli et al, 2011) and form and severity of Pb contamination (Lamb et al, 2009). Consequently, total soil Pb in itself does not predict % bioaccessibility reliably (Walraven et al, 2015). Within a given soil, an increase in % Pb bioaccessibility is commonly observed with decreasing particle size (Juhasz et al, 2011;Madrid et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Bioaccessibility of Ba, Cu, Pb, and Zn in urban garden and orchard soils

Cai

McBride

2016

Environmental Pollution

View full text Add to dashboard Cite

Exposure of young children to toxic metals in urban environments is largely due to soil and dust ingestion. Soil particle size distribution and concentrations of toxic metals in different particle sizes are important risk factors in addition to bioaccessibility of these metals in the particles. Analysis of particle size distribution and metals concentrations for 13 soils, 12 sampled from urban gardens and 1 from orchard found that fine particles (<105 μm) comprised from 22 to 66% by weight of the tested soils, with Ba, Cu, Pb and Zn generally at higher concentrations in the finer particles. However, metal bioaccessibility was generally lower in finer particles, a trend most pronounced for Ba and Pb. Gastric was higher than gastrointestinal bioaccessibility for all metals except Cu. The lower bioaccessibility of Pb in urban garden soils compared to orchard soil is attributable to the higher organic matter content of the garden soils.

show abstract

Factors controlling the oral bioaccessibility of anthropogenic Pb in polluted soils

Cited by 67 publications

References 59 publications

Effects of chemical speciation on the bioaccessibility of zinc in spiked and smelter‐affected soils

Effects of chemical speciation on the bioaccessibility of zinc in spiked and smelter‐affected soils

Bioaccessibility of As and Pb in orchard and urban soils amended with phosphate, Fe oxide and organic matter

Bioaccessibility of Ba, Cu, Pb, and Zn in urban garden and orchard soils

Contact Info

Product

Resources

About