An assessment of lead absorption from soil affected by smelter emissions

Abstract

The purpose of this study was to assess the oral bioavailability of lead in soil collected from a former smelter site in Sandy, Utah, USA. Sprague-Dawley rats (approximately 4 weeks of age, 5 of each sex in group) were given either soil lead or lead acetate mixed in a purified diet (AIN-93G ™) at four different concentrations for 31 consecutive days. Food consumption measurements were used to compute mean daily lead exposures for the soil lead and lead acetate groups. The lead acetate treatment yielded higher concentrations of lead in the blood and bone than the soil lead treatment. Mean blood lead values ranged from below the detection limit (3 μg dL(-1)) to 27.25 μg lead dL(-1) for the lead acetate groups at dose levels of 0.10-2.91 mg lead kg body weight(-1) and from below the detection limit to 8.8 μg lead dL(-1) for the soil lead groups at doses of 0.11-3.43 mg lead kg body weight(-1). At these same doses, mean bone values ranged from 0.52 to 26.92 μg lead g(-1) for the lead acetate groups and from 0.64 to 13.1 μg lead g(-1) for the soil lead groups. Relative per cent bioavailability was estimated by modelling the dose-blood concentration curves for the lead acetate treatment and the dosed soil lead treatment, and then comparing doses that produce an equivalent blood lead concentration. The ratio of the doses of lead acetate and soil lead that produced the same tissue response (i.e., concentration) provided an index of relative bioavailability. For lead, the bioavailability of soil lead relative to lead acetate was 41% at a blood concentration of 6 μg lead dL(-1).

Spatial distribution of lead concentrations in urban surface soils of New Orleans, Louisiana USA

“…Bioavailability predictions vary widely for lead in soil. One study suggests that default available fractions could be as large as 30% (Schoof et al 1995). Overwhelming evidence suggests that toxicity of Pb is reduced over time by natural attenuation such as the complexation of Pb into an unavailable form (Skerfving and Bergdahl 2007).…”

Soil lead bioavailability and in situ remediation of lead‐contaminated soils: A review

“…This is nearly double compared to the bioavailable Pb found in mine waste soils from Butte, Montana [68]. Schoof et al [70] categorized the Pb into three groups based on a mineralogical assessment: (i) soluble and very soluble [Pb carbonate (9%), Pb oxide (4%), manganese Pb oxide (3%), and iron Pb oxide (10%)]; (ii) moderately soluble [Pb arsenate (15%), Pb iron sulfate (6%), and Pb sulfate (17%)]; and (iii) slightly soluble [Pb phosphates (29%)]. Further analysis of phosphate phases by electron microprobe revealed that 83% of the Pb existed as chloropyromorphite, about 15% as an amorphous mixture of metals, and 2% as Pb-bearing apatite.…”

“…Schoof et al [70] assessed the relative bioavailability of Pb in soils collected from a former smelter site in Sandy, Utah. Sprague-Dawley rats were fed either soil Pb or Pb acetate in a purified diet at four different concentrations for 31 consecutive days.…”

Ensaios para determinar a (Bio)disponibilidade de chumbo em solos contaminados: revisão

“…Um dos primeiros estudos in vivo, realizado com ratos, relacionou a biodisponibilidade com a espécie de Pb em solos 31 24 . Os autores 32 do estudo atribuíram os valores mais elevados de biodisponibilidade à presença nas amostras de espécies mais solúveis (como carbonatos, arsenatos e a fase amorfa).…”

“…A variação do pH do estômago também foi utilizada para avaliar as condições do estômago quando em jejum (pH 1,3) e logo após a ingestão de alimentos (pH 4,0), e também em pH 2,5 usado como valor médio. Os resultados foram comparáveis aos de biodisponibilidade obtidos em ratos por Freeman et al 31 (10%) e Schoof et al 32 (36%), principalmente na fase gástrica e com pH 2,5. Para a fase intestinal, devido a maior complexidade, tanto da solução simulada quanto das condições intestinais dos ratos, os resultados apresentam as maiores diferenças relativas entre métodos e pouca reprodutibilidade.…”