Bioaccessibility of Pb in health-related size fractions of contaminated soils amended with phosphate.
Sci Total Environ
; 855: 158831, 2023 Jan 10.
Article
em En
| MEDLINE
| ID: mdl-36165822
ABSTRACT
Lead (Pb) contamination is one of the most significant exposure hazards to human health. Contaminated soil particles may be eroded and transferred either to the atmosphere (<10 µm) or to streams; or they may be incidentally ingested (<200 µm). Among strategies for the long-term management of this risk, one of the most cost-effective is the reduction of Pb mobility and bioavailability via amendment with phosphorus-containing materials. To clarify the effectiveness of P amendment in reducing Pb mobility and bioaccessibility in different soil size fractions, an experiment was performed by adding a soluble P compound to a historically contaminated urban soil (RO), a mining soil (MI), and an uncontaminated spiked soil (SP) at different PPb molar ratios (2.51, 51, and 151). In the <10 µm fraction of soils, P addition reduced bioaccessible Pb only in the SP soil at the highest dose, with little to no effect on RO and MI soils. Similarly, in the coarse fraction, Pb was immobilized only in the SP soil with all three P doses. These results were probably due to the higher stability of Pb in historically contaminated soils, where Pb dissolution is the limiting factor to the formation of insoluble Pb compounds. The bioaccessible proportion of Pb (using SBET method) was higher than 70 % of the total Pb in all soils and was similar in both fine and coarse particle fractions. Due to the enrichment of Pb in finer particles, this implies possible adverse effects to the environment or to human health if these particles escape from the soil. These results call for increasing attention to the effect of remediation activities on fine soil particles, considering their significant environmental role especially in urban and in historically low or moderately contaminated areas.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes do Solo
Limite:
Humans
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Itália