Table 1

Cumulative exposure to monomers as of the end of follow-up in the overall six-plant cohort and in cohort subgroups

Group
(total number in group)
Butadiene ppm-yearsStyrene ppm-years
N (%)*RangeMedian (IQR)Mean (SD)N (%)RangeMedian (IQR)Mean (SD)
Total cohort (21 087)14 004 (66)>0.00–926448 (11–167)187 (517)15 422 (73)>0.00–161811 (2.8–36)38 (98)
Sex
 Male (16 579)12 814 (77)>0.00–926454 (13–178)197 (537)14 006 (84)>0.00–161813 (3.4–38)40 (101)
 Female (4508)1190 (26)>0.00–19808.0 (1.6–45)76 (184)1416 (31)>0.00–3801.8 (0.3–11)19 (48)
Plant, location
 Kentucky (1563)1144 (73)>0.00–149975 (15–245)195 (280)1171 (75)0.01–47720 (5.8–48)38 (53)
 Louisiana (2463)1815 (74)0.05–418572 (20–230)251 (502)1782 (72)>0.00–146916 (4.6–57)71 (169)
 Louisiana (2849)1524 (53)0.01–926473 (15–320)483 (1267)2092 (73)>0.00–161813 (3.7–48)65 (178)
 Texas (2929)1690 (58)>0.00–211438 (10–134)132 (239)2227 (76)>0.00–5165.9 (1.7–22)21 (40)
 Ontario (7044)4936 (70)>0.00–514143 (8.3–143)139 (282)4846 (69)>0.00–44212 (2.4–36)33 (54)
 Texas (4239)2895 (68)0.02–157532 (8.6–120)102 (174)3304 (78)>0.00–36810 (2.5–29)23 (35)
Ever hourly
 Yes (15 109)11 876 (79)>0.00–926465 (16–203)216 (556)13 406 (89)>0.00–161814 (3.6–42)43 (104)
 No (5978)2128 (36)>0.00–9167.4 (1.7–23)24 (59)2016 (34)>0.00–3102.5 (0.5–8.1)7.8 (16)
Race
 White (18 674)12 273 (66)>0.00–514144 (10–149)139 (268)13 297 (71)>0.00–68110 (2.5–32)27 (46)
 Black (2413)1731 (72)0.01–9264105 (18–368)526 (1236)2125 (88)0.01–161824 (5.5–87)105 (225)
Hire year
 1943–1949 (5404)3600 (67)>0.00–926477 (20–253)257 (650)3938 (73)0.01–161813 (3.8–48)50 (125)
 1950–1959 (5613)4005 (71)>0.00–906397 (30–266)260 (617)4279 (76)0.02–146225 (6.4–56)55 (117)
 1960–1969 (4333)2871 (66)>0.00–710242 (11–130)134 (334)3065 (71)>0.00–110513 (3.3–34)30 (63)
 ≥1970 (5737)3528 (62)>0.00–451612 (3.0–41)75 (287)4140 (72)>0.00–6973.8 (0.9–13)16 (51)
All decedents (9665)6914 (72)>0.00–926479 (21–245)245 (607)7481 (77)>0.00–161817 (4.4–49)50 (119)
 All leukaemia (132)103 (78)1.92–7741121 (34–364)367 (873)109 (83)1.09–120327 (8.4–61)62 (158)
  Lymphoid leukaemia (52)39 (75)1.92–7741225 (45–425)542 (1303)42 (81)1.65–120329 (8.6–69)90 (243)
  Myeloid leukaemia (67)53 (79)5.03–201070 (26–230)238 (425)56 (84)1.09–34121 (5.4–49)39 (57)
   AML†(41)32 (78)5.03–201062 (20–188)158 (351)35 (85)1.09–34120 (5.2–36)31 (58)
 B-cell malignancy‡ (213)148 (69)>0.00–7741125 (29–373)334 (756)163 (77)0.09–120321 (4.6–62)64 (157)
  NHL† (110)76 (69)>0.00–1496121 (19–335)234 (302)86 (78)0.09–23124 (6.0–60)41 (49)
  Multiple myeloma (60)40 (67)>0.00–2398111 (34–395)314 (527)43 (72)0.21–84015 (2.8–78)82 (177)
  • *Number of exposed employees (% of total number in each group).

  • † AML, acute myeloid leukemia; NHL, non-Hodgkin’s lymphoma.

  • ‡Included lymphoid leukaemia, non-Hodgkin’s lymphoma and multiple myeloma.

  • †AML, acute myeloid leukaemia; NHL, non-Hodgkin’s lymphoma.