Table 1.

Historical occupational EC in the trucking industry (μg/m³).

Table 1. Historical occupational EC in the trucking industry (μg/m3).
								Zaebst studya (1988–1989)
		TrIPSb (2001–2006)						Measured						Predictedc GM		Historicald multiplier
Job		No. of observations		GM		GSD		No. of observations		GM		GSD
Background/clerks		699		0.5		3.2		23		1.1		2.0		1.1		NAe
LH		388		1.1		2.3		72		3.8		2.3		2.3		1.7
P&D (warm)		535		1.2		2.3		25		6.3		1.9		2.5		2.5
P&D (cold)		197		1.0		3.5		31		2.8		1.6		2.2		1.3
Dockworker (propane)		632		0.9		2.2		12		1.3		2.0		1.36		1.0
Dockworker (diesel)								54		27.2		1.7				20.9f
Dockworker (gasoline)								9		5.5		1.6				4.2f
Mechanics (warm)		96		1.5		2.4		38		4.8		2.4		2.0		2.4
Mechanics (cold)		53		4.3		4.0		42		28.0		2.8		7.6		3.7
Abbreviations: GM, geometric mean; GSD, geometric standard deviation; NA, not applicable. aZaebst et al. (1991). bSmith et al. (2006) and Davis et al. (2009). cRepresents predictions from baseline exposure model adjusted for background conditions. dHistorical multipliers were generated based on relationship between measured geometric means from Zaebst et al. (1991) and those predicted by baseline exposure model, unless otherwise specified; linear extrapolation applied to years between study periods. eYear-specific background multipliers applied for 1971–1999 are based on archived COH data. fHistorical multipliers for dockworkers driving diesel or gasoline forklifts were developed based on ratio to propane as observed by Zaebst et al. (1991). Empty cells indicate that no diesel or gasoline forklifts were observed for Smith et al. 2006.