Table 1.

International Agency for Research on Cancer cohort of reinforced plastics workers exposed to styrene, 1945–1991, cohort characteristics

	N	%*	Person-years
All workers	37 021	100	506 459
Men	31 692	85	428 006
Women	5692	15	78 453
Exposed job	31 803	85	407 459
Laminators	8946	24	132 062
Unexposed job	3797	11	66 412
Unknown job	1833	5	32 705
Employment duration (years)
<2	22 865	62	307 521
2 to <5	5583	15	82 698
≥5	7086	19	95 895
Unknown	1487	4	20 345
Exposure duration (years)
<2	24 715	67	339 328
2 to <5	4593	12	64 646
≥5 y	5075	14	61 514
Unknown	2638	7	40 971

	Mean	Range
Mean employment duration (years)	3.1	<0.01–62.0
Mean exposure duration (years)	2.2	0–33.5
Mean length of follow-up (years)	12.8	0–45.0
Mean styrene exposure (ppm)	63.1	0–205.0
Mean cumulative styrene exposure (ppm-years)	158.0	0–4543.1

*Per cents may not add to 100 because of rounding.