Table 4 In vitro procedures applied to Pb particles and compared with in vivo data for subsequent calibration (2 pages)

Ruby et al. 1993 PBET-GI[55]

Mine wastes

1/10 g.mL^-1

2 h @ pH 7.0

· In vivo results on rabbits (1 sample): 10.7% (blood based RBA at t = 1 h), and 9^±4 % (gastric solubility,t = 1.5 h)

2 h @ pH 1.3 Pepsin; organic acids; HCl

NaHCO_3; pancreatin; bile

Ruby et al. 1996 PBET-GI[74]

Mine wastes Residential soils Tailings

1/100 g.mL^-1

4 h @ pH 7.0

· In vivo relative Pb bioavailability in rats (based on BLLs, Y axis) correlation to IVBA results from the G phase (X axis): R² = 0.93, n=7, intercept 3.2, slope 1.4

1 h @ pH 2.5 Pepsin; organic acids; HCl

NaHCO_3; pancreatin; bile

· Correlation with I phase: R² = 0.76

Medlin 1997

PBET-G[88]

15 soils or soil-like materials (EPA Region VIII)

1/111 g.mL^-1

· In vivo point estimates in piglets (Y-axis) correlated to in vitro results (X-axis):

1 h @ pH 1.5 Pepsin; organic acids; acetic acids; HCl

R²=0.63, n=15, intercept −8.21, slope 0.90, p < 0.001^*

· Extensive QA/QC protocol

Brown et al. 2003 PBET-G[58]

Urban soil treated with various biosolids (n=9)

1/100 g.mL^-1

· In vivo bone bioavailability reduction % in rats correlated to in vitro bioaccessibility reduction with the treatment of soils (R=0.9)

1 h @ pH 2.3 Pepsin; organic acids; HCl

Hettiarachchi et al. 2003 PBET-GI[59]

Joplin soil treated or not with Mn, P, or CRYP (n=15)

1/100 g.mL^-1

1 h @ pH 6.5

· In vivo point estimate RBA in rats (Y-axis) correlated to in vitro results (X-axis)

1 h @ pH 2.0 Pepsin; organic acids; HCl

NaHCO_3; pancreatin; bile

G phase: R²=0.95, intercept 11, slope 0.82

I phase: R²=0.77, intercept 12, slope 1.87

Schroder et al. 2004 IVG[70]

18 soils (EPA Region VIII)

1/150 g.mL^-1 1 h @ pH 1.8 Pepsin; NaCl; HCl

1 h @ pH 5.5 Pancreatin; bile; NaHCO₃; decanol

· In vivo blood RBA (X-axis) in piglets correlated (p < 0.001) to in vitro data (Y-axis)^†:

- G (R=0.93) & I (R=0.80) results, with dough

- G results no dough (R=0.89)

· Best correlation for G phase with dough: R²=0.86, n=18, intercept 2.97, slope 0.39

Marschner et al. 2006 IVG[62]

5 soils, with or without milk powder

1/40 g.mL^-1

6 h @ pH 7.5

· Absence of correlation between in vivo bioavailability in piglets and in vitro results

2 h @ pH 2.0 Pepsin; NaCl; HCl

NaHCO_3; trypsin; bile; pancreatin; urea; inorganics

Oomen et al. 2006

RIVM[86]

11 soils or soil-like material (EPA Region VIII)

5 min @ pH 6.5

1/37.5 or 1/375 g.mL^-1

2 h @ pH 5.5-6.5

· In vivo point estimates in piglets (X-axis) correlated to relative in vitro fasted model results (Y-axis):

2 h @ pH 1.0-2.0

(in)organics, pancreatin, bile, BSA, lipase, CaCl₂

G phase: R²=0.68-0.79, intercept 0, slope 0.79-1.08

I phase: R²=0.66-0.81, intercept 0, slope 0.69-1.16

(in)organics, pepsin, mucin, BSA

Drexler and Brattin 2007; USEPA 2007 RBALP[43, 84]

19 soil-like materials from EPA region VIII,

1/100 g.mL^-1

· In vivo RBA point estimates in piglets (Y-axis) correlated to in vitro results (X-axis) : weighted R²=0.924, n=19, intercept −0.028, slope 0.878, p < 0.001

1 h @ pH 1.5

Glycine; HCl

· Extensive QA/QC protocol and statistical analyses

· Precision 7% within samples, and 4-6% within laboratories (round robin testing)

Bannon et al. 2009

RBALP[64]

8 small arms range soils

· In vivo point estimates on piglets: 108^±18% · In vitro results: 83^±1-100^±3%

Glycine; HCl

Caboche 2009 Denys et al. 2012 UBM[65, 66]

14 mining and smelting soils

5 min @ pH 6.5

1/37.5 g.mL^-1

1 h @ pH 1.2-1.7

4 h @ pH 5.8-6.8

· In vivo kidney RBA in piglets (X-axis) correlated to in vitro results adjusted by PbAc solubility in the G and I phases (Y-axis):

(in)organics, pancreatin, bile, BSA, lipase, CaCl₂

G phase: R²=0.93, intercept 1.10, slope 1.86, p < 0.01

(in)organics, mucin, uric acid, alpha-amylase

I phase: R²=0.89, intercept 1.09, slope 1.09, p < 0.01

(in)organics, pepsin, mucin, BSA

Juhasz et al. 2009 SBRC[67]

5 incinerator & urban soils; 5 soils from Marschner et al.[62]

1/100 g.mL^-1 1 h @ pH 1.5 Glycine, HCl

4 h @ pH 6.5NaOH, pancreatin, bile

· In vivo blood RBA in piglets (Y-axis) correlated to relative in vitro data for the I phase (X-axis):

R²=0.53, intercept 1.98, slope 0.58 (urban & incinerator soils)

R²=0.47, intercept 29.5, slope 0.42 (soils from Marschner et al., 2006 study)

Wragg et al. 2011 UBM[95]

12 soils (mining, composite, phosphate-treated), 1 dust

5 min @ pH 6.5 (in)organics, mucin, uric acid, alpha-amylase

1/100 g.mL^-1 2 h @ pH 1.2-1.4

4 h @ pH 6.3±0.5 (in)organics, pancreatin, bile, BSA, lipase, CaCl₂

· In vivo RBA in piglets (X-axis) correlated to in vitro results adjusted by PbAc solubility in the G and I phases (Y-axis):

(in)organics, pepsin, mucin, BSA

G phase: R²=0.61, slope 0.78, median RSD 4% within samples, 33% within laboratories

I phase: R²=0.57, slope 0.38, median RSD 15% within samples, 81% within laboratories

Smith et al. 2011 RBALP[68]

1/100 g.mL^-1 1 h @ pH 1.5 Glycine, HCl

· In vivo blood RBA in mice (X-axis) correlated to relative in vitro data (Y-axis):

R²=0.78, intercept 30.207, slope 0.69

Smith et al. 2011 SBRC[68]

1/100 g.mL^-1 1 h @ pH 1.5 Glycine, HCl

4 h @ pH 6.5 NaOH, pancreatin, bile

· In vivo blood RBA in mice (X-axis) correlated to relative in vitro data (Y-axis):

R²=0.88, intercept −7.02, slope 1.06 (SBRC, I phase results)