Results of working environment measurement of tar and benzo[a]pyrene (BaP) in the air by workshop in the plant, 1973 (by Japan Industrial Safety and Health Association (JISHA)) and 1974 (by Nakaminami)*
| JISHA | Nakaminami | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Tar in the air (mg/m3) | BaP in the air (μg/m3) | Tar in the air (mg/m3) | ||||||||
| Workshop/ measurement method† | Number of samples‡ | Mean | Range | Number of samples‡ | Mean | Range | Number of samples‡ | Mean | Range | BaP in the air (μg/m3)¶ |
| *These data were submitted as evidence of the plaintiff (measured by Nakaminami) and of the defence (measured by JISHA) to the trial on occupational cancer cases. | ||||||||||
| †“A sampling” means area sampling at randomly selected points in the unit work area. “B sampling” means area sampling at close proximity to workers whose exposure is considered to be maximum.17 | ||||||||||
| ‡Number in parentheses is number of sampling points. | ||||||||||
| §Tr, traceable—that is, the concentration of BaP less than 0.00 mg/m3 but not zero. It was assumed to be zero for calculation of the means. | ||||||||||
| ¶Number of samples = 1. | ||||||||||
| **Mean BaP concentration. | ||||||||||
| Crushing | ||||||||||
| A sampling | 6 (3) | 1.52 | 0.26–4.69 | 4 (2) | 40 | Tr§–82 | 1 (1) | 1.82 | – | 10.0 |
| B sampling | 2 (1) | 0.79 | 0.77–0.82 | |||||||
| Blending | ||||||||||
| A sampling | 6 (3) | 0.57 | 0.31–1.15 | 1 (1) | 0.84 | – | 7.5 | |||
| B sampling | 4 (2) | 1.54 | 0.15–2.96 | 1 (1) | 65 | – | ||||
| Kneading | ||||||||||
| A sampling | 4 (2) | 0.30 | 0.23–0.46 | 3 (1) | 7.05 | 0.65–16.80 | 24.0 | |||
| B sampling | 9 (5) | 1.06 | 0.29–4.10 | 2 (2) | 51 | Tr§ 102 | ||||
| Shaping | ||||||||||
| A sampling | – | – | – | 2 (1) | 2.38 | 1.90–2.86 | 4.4 | |||
| B sampling | 12 (6) | 0.38 | 0.15–1.08 | |||||||
| Impregnation | ||||||||||
| A sampling | 2 (1) | 0.14 | 0.09–0.18 | |||||||
| Graphitisation | ||||||||||
| A sampling | – | – | – | 1 (1) | Tr§ | – | ||||
| All workshops | ||||||||||
| A sampling | 18 (9) | 0.81 | 0.09–4.69 | 5 (3) | 32.2 | Tr§–82 | 7 (4) | 3.13 | 0.65–16.80 | 11.5** |
| B sampling | 27 (14) | 0.81 | 0.15–4.10 | 3 (3) | 55.7 | Tr§–102 | ||||









