Table 5.

Benchmark dose calculations of excess risk of vibration perception impairment (in the foot) based on the biomarker Hb-adduct levels

ACM air conc.[1] mg/m3	Excess Hb-adduct[2] nmol/gm	Excess Hb-adduct[3] nonsmokers nmol/gm	Excess Hb-adduct[4] smokers nmol/gm	Excess risk of Foot VPT impairment after 3 years/1000	Range of observed Hb-adduct in Chinese chemical workers2 at 3 yr	Excess risk of Foot VPT impairment at 2 months/1000	Range of observed Hb-adduct in Swedish tunnel workers1 at 2 mo
0.0001	0.001	0.032	0.053	0.26		0
0.0002	0.002	0.052	0.086	0.28		0
0.0005	0.005	0.100	0.167	0.31		0
0.0010	0.01	0.165	0.274	0.38		0
0.0022	0.02	0.272	0.451	0.51		0
0.0064	0.05	0.524	0.871	0.90		0
0.014	0.1	0.862	1.432	1.53		0
0.031	0.2	1.417	2.355	2.81		0.04
0.090	0.5	2.734	4.545	6.82	X	0.26
0.20	1	4.496	7.473	13.6	X	0.60
0.44	2	7.393	12.289	28.1	X	1.3	X
1.27	5	14.267	23.719	79.8	X	3.5	X
2.82	10	23.459	39.004	177	X	7.1
6.25	20	38.574	64.140	374	X	14.5
9.97	30	51.598	85.801	-	X	-

^1.Calculated from Hb-adduct levels using Jones et al., 2006, Fig 2: [ACM(air)] = (Hb_add/10)^1.15

^2.Excess Hb-adduct above baseline in general population, uncorrected for smoking or other demographic determinants, Calleman et al., 1994, Table 6

^3.Calculated from Sams et al., 2015 (derived from Table 5): Hb-adduct (nonsmokers) = 12.29×air^0.624

^4.Calculated from Sams et al., 2015 (derived from Table 5): Hb-adduct (smokers) = 20.43×air^0.624

ACM – acrylamide VPT – Vibratory Perceived Threshold