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Table 9
*Risk of lung cancer among KNR workers by year of first exposure and time since first exposure in Andersen et al. (1996) [4] and Grumsrud et al. (2003) [7] studies^a*
Year of first exposure	Time since first exposure (yr)

	1–14			15+			Total

	Obs	SIR	95% CI^b	Obs	SIR	95% CI	Obs	SIR	95% CI

Andersen et al. (1996):
1916–44	0	-		30	440	300–630	30	470	320–670
1945–55	7	220	90–450	95	330	270–400	102	320	270–390
1956–67	5	180	60–420	28	280	190–400	33	260	180–360
1968–83	6	230	80–490	11	410	200–730	17	320	180–510

Grimsrud et al. (2003):
1910–29	NA^c	-	-	17	480	280, 770	17	480	280, 760
1930–55	10	250	120, 460	160	270	230, 310	170	270	230, 310
1956–78	8	110	50, 220	67	250	190, 310	75	220	170, 270
1979–89	2	240	30, 880	3	580	120, 1690	5	370	120, 870

^aFrom Table three in Andersen et al. (1996) [4] and Table two in Grimsrud et al. (2003) [7]. ^bCI, confidence interval. ^cNA, not applicable.
Heller et al. Journal of Occupational Medicine and Toxicology 2009 4:23 doi:10.1186/1745-6673-4-23

Table 9