An inter-laboratory trial of the unified BARGE bioaccessibility method for arsenic, cadmium and lead in soil

• Published in: The Science of the total environment 2011-09, Vol.409 (19), p.4016-4030
• Main Authors: Wragg, Joanna, Cave, Mark, Basta, Nick, Brandon, Esther, Casteel, Stan, Denys, Sebastien, Gron, Christian, Oomen, Agnes, Reimer, Kenneth, Tack, Karine, Van de Wiele, Tom
• Format: Article
• Language: English
• Subjects: Arsenic - analysis; Arsenic - chemistry; Barges; Bioaccessibility; Bioavailability; Biological and medical sciences; Biological Availability; Cadmium; Cadmium - analysis; Cadmium - chemistry; Carcinogenesis, carcinogens and anticarcinogens; Chemical agents; Chemical and industrial products toxicology. Toxic occupational diseases; Criteria; Environmental Monitoring - methods; Environmental Sciences; Humans; In vitro; In vivo; Inter-laboratory trial; Intestines; Intestines - metabolism; Lead - analysis; Lead - chemistry; Mathematical models; Medical sciences; Metals and various inorganic compounds; Models, Biological; Soil; Soil (material); Soil - chemistry; Soil Pollutants - analysis; Soil Pollutants - chemistry; Stomach; Stomach - metabolism; Surgical implants; Toxicology; Tumors
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2011.05.019

The Bioaccessibility Research Group of Europe (BARGE) has carried out an inter-laboratory trial of a proposed harmonised in vitro physiologically based ingestion bioaccessibility procedure for soils, called the Unified BARGE Method (UBM). The UBM includes an initial saliva phase and simulated stomach and intestine compartments. The trial involved the participation of seven laboratories (five European and two North American) providing bioaccessibility data for As (11 samples), Cd (9 samples) and Pb (13 samples) using soils with in vivo relative bioavailability data measured using a swine model. The results of the study were compared with benchmark criteria for assessing the suitability of the UBM to provide data for human health risk assessments. Mine waste and slag soils containing high concentrations of As caused problems of poor repeatability and reproducibility which were alleviated when the samples were run at lower soil to solution ratios. The study showed that the UBM met the benchmark criteria for both the stomach and stomach & intestine phase for As. For Cd, three out of four criteria were met for the stomach phase but only one for the stomach & intestine phase. For Pb two, out of four criteria were met for the stomach phase and none for the stomach & intestine phase. However, the study recommends tighter control of pH in the stomach phase extraction to improve between-laboratory variability, more reproducible in vivo validation data and that a follow up inter-laboratory trial should be carried out. ► An inter-laboratory trial of a in vitro bioaccessibility method for soils, the Unified BARGE Method (UBM), is described. ► The trial used 7 laboratories providing data for As (11 samples), Cd (9 samples) and Pb (13 samples). ► Mine waste and slag soils caused problems of poor repeatability and reproducibility. ► The study showed that the UBM met benchmark criteria for both compartments for As and for the stomach phase for Cd and Pb. ► Recommendations included tighter control of pH in the stomach phase to improve reproducibility.