Table 3.
Associations of embalming, compared with no embalming, and risk for all lymphohematopoietic malignancies (LHPM) (ICD-8 200–209; n = 168), LHPM of lymphoid (International Classification of Diseases, Eighth Revision [ICD-8] 200-204, n = 99) and nonlymphoid origin (ICD-8 205, 206, 208 and 209; n = 48), myeloid leukemia (ICD-8 205; n = 34), and brain tumors (malignant: ICD-8 191 and 192; n = 38; benign: ICD-8 225; n = 2; unspecified: ICD-8 238.1; n = 8), adjusted for date of birth, age at death, sex, data source, and smoking*
| LHPM |
|||||||||||
| All |
Lymphoid origin |
Nonlymphoid origin |
Myeloid leukemia |
Brain tumors |
|||||||
| Characteristic | No. of control subjects | No. of case subjects | OR (95% CI) | No. of case subjects | OR (95% CI) | No. of case subjects | OR (95% CI) | No. of case subjects | OR (95% CI) | No. of case subjects | OR (95% CI) |
| Embalming | |||||||||||
| Never | 55 | 24 | 1.0 (Ref.) | 18 | 1.0 (Ref.) | 4 | 1.0 (Ref.) | 1 | 1.0 (Ref.) | 6 | 1.0 (Ref.) |
| Ever | 210 | 144 | 1.4 (0.8 to 2.6) | 81 | 1.1 (0.5 to 2.1) | 44 | 3.0 (1.0 to 9.5) | 33 | 11.2 (1.3 to 95.6) | 42 | 1.9 (0.7 to 5.3) |
| Questionnaire-based metrics | |||||||||||
| Duration of working in jobs with embalming, y | |||||||||||
| 0 | 55 | 24 | 1.0 (Ref.) | 18 | 1.0 (Ref.) | 4 | 1.0 (Ref.) | 1 | 1.0 (Ref.) | 6 | 1.0 (Ref.) |
| >0 to 20 | 71 | 28 | 0.8 (0.4 to 1.8) | 16 | 0.7 (0.3 to 1.6) | 7 | 1.4 (0.3 to 6.0) | 6 | 5.0 (0.5 to 51.6) | 13 | 1.5 (0.5 to 5.0) |
| >20 to 34 | 69 | 50 | 1.5 (0.8 to 2.8) | 32 | 1.2 (0.6 to 2.6) | 16 | 2.1 (0.9 to 11.0) | 13 | 12.9 (1.4 to 117.1) | 18 | 2.4 (0.8 to 7.6) |
| >34 | 70 | 66 | 1.8 (1.0 to 3.4) | 33 | 1.2 (0.6 to 2.5) | 21 | 3.7 (1.1 to 12.2) | 14 | 13.6 (1.6 to 119.7) | 11 | 1.9 (0.6 to 6.1) |
| P for trend† | .058 (.131) | .449 (.360) | .046 (.348) | .020 (.588) | .189 (.394) | ||||||
| No. of embalmings | |||||||||||
| 0 | 55 | 24 | 1.0 (Ref.) | 18 | 1.0 (Ref.) | 4 | 1.0 (Ref.) | 1 | 1.0 (Ref.) | 6 | 1.0 (Ref.) |
| >0 to 1422 | 70 | 29 | 0.9 (0.6 to 1.8) | 17 | 0.7 (0.3 to 1.6) | 8 | 1.8 (0.5 to 6.9) | 7 | 7.6 (0.8 to 73.5) | 17 | 2.2 (0.7 to 6.6) |
| >1422 to 3068 | 70 | 62 | 1.9 (1.0 to 3.6) | 37 | 1.5 (0.7 to 3.0) | 15 | 3.0 (0.9 to 10.5) | 12 | 12.7 (1.4 to 116.7) | 14 | 1.9 (0.6 to 6.1) |
| >3068 | 70 | 53 | 1.5 (0.8 to 2.9) | 27 | 1.0 (0.5 to 2.2) | 21 | 3.9 (1.2 to 12.8) | 14 | 12.7 (1.4 to 112.8) | 11 | 1.5 (0.5 to 5.0) |
| P for trend† | .477 (.844) | –.963 (–.865) | .247 (.662) | .314 (–.891) | –.960 (–.586) | ||||||
| Questionnaire- and model-based exposure metrics | |||||||||||
| Cumulative formaldehyde exposure, ppm-h‡ | |||||||||||
| 0 | 55 | 24 | 1.0 (Ref.) | 18 | 1.0 (Ref.) | 4 | 1.0 (Ref.) | 1 | 1.0 (Ref.) | 6 | 1.0 (Ref.) |
| >0 to 4058 | 70 | 40 | 1.3 (0.6 to 2.5) | 23 | 0.9 (0.4 to 2.0) | 10 | 2.4 (0.6 to 8.9) | 9 | 10.2 (1.1 to 95.6) | 15 | 1.9 (0.6 to 6.1) |
| >4058 to 9253 | 70 | 49 | 1.4 (0.8 to 2.8) | 33 | 1.3 (0.6 to 2.8) | 12 | 2.3 (0.7 to 8.2) | 10 | 9.4 (1.0 to 85.7) | 17 | 2.3 (0.7 to 7.2) |
| >9253 | 70 | 55 | 1.6 (0.8 to 3.0) | 25 | 1.0 (0.4 to 2.0) | 22 | 4.0 (1.2 to 13.2) | 14 | 13.2 (1.5 to 115.4) | 10 | 1.4 (0.4 to 4.7) |
| P for trend† | .422 (.753) | –.965 (–.912) | .140 (.523) | .192 (.966) | .682 (–.880) | ||||||
| Average formaldehyde intensity while embalming, ppm | |||||||||||
| 0 | 55 | 24 | 1.0 (Ref.) | 18 | 1.0 (Ref.) | 4 | 1.0 (Ref.) | 1 | 1.0 (Ref.) | 6 | 1.0 (Ref.) |
| >0 to 1.4 | 70 | 53 | 1.6 (0.9 to 3.2) | 34 | 1.4 (0.6 to 2.9) | 14 | 3.0 (0.8 to 10.5) | 10 | 11.1 (1.2 to 106.3) | 14 | 1.7 (0.5 to 5.4) |
| >1.4 to 1.9 | 70 | 47 | 1.4 (0.7 to 2.7) | 26 | 1.0 (0.5 to 2.2) | 15 | 3.3 (0.9 to 11.6) | 13 | 14.8 (1.6 to 136.9) | 11 | 1.4 (0.4 to 4.7) |
| >1.9 | 70 | 44 | 1.3 (0.7 to 2.5) | 21 | 0.9 (0.4 to 1.9) | 15 | 2.9 (0.8 to 9.7) | 10 | 9.5 (1.1 to 86.0) | 17 | 2.3 (0.8 to 6.7) |
| P for trend† | .591 (–.443) | –.598 (–.287) | .096 (–.997) | .058 (–.722) | .163 (.588) | ||||||
| TWA8 formaldehyde intensity, ppm | |||||||||||
| 0 | 55 | 24 | 1.0 (Ref.) | 18 | 1.0 (Ref.) | 4 | 1.0 (Ref.) | 1 | 1.0 (Ref.) | 6 | 1.0 (Ref.) |
| >0 to 0.10 | 70 | 47 | 1.3 (0.7 to 2.6) | 32 | 1.2 (0.6 to 2.6) | 9 | 1.8 (0.5 to 6.5) | 8 | 8.4 (0.8 to 79.3) | 20 | 2.7 (0.9 to 8.1) |
| >0.10 to 0.18 | 70 | 52 | 1.6 (0.8 to 3.1) | 25 | 1.0 (0.5 to 2.1) | 20 | 4.2 (1.2 to 14.3) | 13 | 13.6 (1.5 to 125.8) | 12 | 1.6 (0.5 to 5.2) |
| >0.18 | 70 | 45 | 1.4 (0.7 to 2.8) | 24 | 1.0 (0.5 to 2.1) | 15 | 3.4 (1.0 to 11.8) | 12 | 12.0 (1.3 to 107.4) | 10 | 1.2 (0.4 to 4.1) |
| P for trend† | .635 (–.855) | –.766 (–.605) | .256 (.951) | .396 (–.642) | –.567 (–.177) | ||||||
| Peak formaldehyde exposure, ppm | |||||||||||
| 0 | 55 | 24 | 1.0 (Ref.) | 18 | 1.0 (Ref.) | 4 | 1.0 (Ref.) | 1 | 1.0 (Ref.) | 6 | 1.0 (Ref.) |
| >0 to 7.0 | 67 | 48 | 1.6 (0.8 to 3.2) | 29 | 1.2 (0.6 to 2.7) | 14 | 3.4 (1.0 to 12.1) | 12 | 15.2 (1.6 to 141.6) | 12 | 1.5 (0.5 to 5.0) |
| >7.0 to 9.3 | 72 | 55 | 1.6 (0.9 to 3.1) | 37 | 1.5 (0.7 to 3.2) | 12 | 2.2 (0.6 to 7.7) | 9 | 8.0 (0.9 to 74.0) | 18 | 2.3 (0.8 to 7.2) |
| >9.3 | 71 | 41 | 1.2 (0.6 to 2.3) | 15 | 0.6 (0.2 to 1.3) | 18 | 3.8 (1.1 to 12.7) | 12 | 13.0 (1.4 to 116.9) | 12 | 1.7 (0.5 to 5.3) |
| P for trend† | .555 (–.302) | –.523 (–.111) | .089 (–.944) | .036 (–.778) | .271 (.936) | ||||||
*
CI = confidence interval; OR = odds ratio; ppm, parts per million; Ref. = referent; minus sign (−) = a negative trend; TWA8 = 8-hour time-weighted average.
†
P for trend (Wald test) among exposed only in parentheses. All statistical tests were two-sided.
‡
If 1950 working hours/year is assumed, then 1 ppm-y corresponds to 1950 ppm-h (ie, category cut points in ppm-y are 2.1 and 4.7).