Table 7.

Comparison of observed and expected leukemia and NPC mortality in formaldehyde-exposed workers.

		Leukemia		NPC
Cohort	No. of Workers	Observed	Expectedb	Observed	Expected
NCIa	25,600	116	≈116	8	2
Coggin	14,000	12	13	1	2
Pinkerton	11,000	24	≈24	0	1
Total	50,600	152	153	9	5

^aBeane Freeman et al. (2009) for leukemia and Hauptmann et al. (2004) for NPC.

^bWhen only observed mortality was reported, the expected mortality was calculated by dividing the observed mortality by the SMR.