Details

Autor(en) / Beteiligte

• Zia, Munir Hussain
• Codling, Eton E.
• Scheckel, Kirk G.
• Chaney, Rufus L.

Titel

In vitro and in vivo approaches for the measurement of oral bioavailability of lead (Pb) in contaminated soils: A review

Ist Teil von

• Environmental pollution (1987), 2011-10, Vol.159 (10), p.2320-2327

Ort / Verlag

Kidlington: Elsevier Ltd

Erscheinungsjahr

2011

Quelle

MEDLINE

Beschreibungen/Notizen

• We reviewed the published evidence of lead (Pb) contamination of urban soils, soil Pb risk to children through hand-to-mouth activity, reduction of soil Pb bioavailability due to soil amendments, and methods to assess bioaccessibility which correlate with bioavailability of soil Pb. Feeding tests have shown that urban soils may have much lower Pb bioavailability than previously assumed. Hence bioavailability of soil Pb is the important measure for protection of public health, not total soil Pb. Chemical extraction tests (Pb bioaccessibility) have been developed which are well correlated with the results of bioavailability tests; application of these tests can save money and time compared with feeding tests. Recent findings have revealed that fractional bioaccessibility (bioaccessible compared to total) of Pb in urban soils is only 5–10% of total soil Pb, far lower than the 60% as bioavailable as food-Pb presumed by U.S.-EPA (30% absolute bioavailability used in IEUBK model). ► Among direct exposure pathways for Pb in urban environments, inadvertent ingestion of soil is considered the major concern. ► The concentration of lead in house dusts is significantly related to that in garden soil, and is highest at older homes. ► In modeling risks from diet/water/soil Pb, US-EPA presumes that soil-Pb is 60% as bioavailable as other dietary Pb. ► Joplin study proved that RBALP method seriously underestimated the ability of phosphate treatments to reduce soil Pb bioavailability. ► Zia et al. method has revealed that urban soils have only 5–10% bioaccessible Pb of total Pb level. Improved risk evaluation and recommendations for Pb contaminated soils should be based on bioavailability-correlated bioaccessible soil Pb rather than total soil Pb.