Table 2 Characteristics and findings for Plant 1 (Wallingford) and Plants 2-10 combined in 2004 NCI update

Entry year

1940

1934–1958

No. subjects

4261

21358

Formaldehyde exposure

 % Subjects ever exposed

87.7

89.8

 % Subjects ever in highest peak category

46.1

20.1

 Median AIE (ppm) ^a

1.023

0.366

  (5–95 %-tile)

(.310–1.417)

(.052–1.257)

 Median Cum (ppm-years) ^a

.9

3.2

  (5–95 %-tile)

(.1–17.2)

(.06–23.5)

 Median Dur (years) ^a

1.0

13.1

  (5–95 %-tile)

(.1–24.4)

(.3–32.1)

Observed deaths and SMRs

  All workers

  Observed deaths

6

5

  SMR-US (expected deaths)

5.44** (1.1)

.97 (5.2)

   (95 % CI)

(2–11.85)

(.31–2.26)

  SMR-local (expected deaths)

5.57** (1.1)

1.06 (4.7)

   (95 % CI)

(2.04–12.12)

(.35–2.48)

  Exposed workers

  Observed deaths

6

3

  SMR-US (expected deaths)

7.23** (.8)

.74 (4.1)

   (95 % CI)

(2.65–15.74)

(.15–2.16)

  SMR-local (expected deaths)

7.34** (.8)

.82 (3.6)

   (95 % CI)

(2.69–15.97)

(.17–2.41)

  Unexposed workers

  Observed deaths

0

2

  SMR-US (expected deaths)

- (.3)

1.81 (1.1)

   (95 % CI)

(0–13.55)

(.22–6.53)

  SMR-local (expected deaths)

- (.3)

1.88 (1.1)

  (95 % CI)

(0–14.20)

(.23–6.80)