were reported). Workers from 10 of the offices studied had been referred to the clinic of Occupational Medicine at Southern Hospital because of health problems associated with handling CCP. The authors measured ambient temperatures, relative humidities, and ventilation efficiencies. As a measure of the chemical emissions from CCP, airborne concentrations of the solvents from microcapsules were analyzed using activated charcoal tubes. The carbon-disulfide-desorbed solvents were analyzed by GC, and detection limits varied between 0.001 and 0.02 mg/m3.
Airborne concentrations of total dust, dust-bound solvent, solvent in the vapor phase, and formaldehyde were also determined in a laboratory situation using a 34-m3 room with an air-exchange rate of 0.8 times/hr. Thirty sheets of each type of paper were handled in a standardized procedure for 60 min. Table 3-3 shows that airborne solvent concentrations are generally low, and they are considerably lower in the office environment than in the printing shop. Area samples were also consistently lower than personal samples, suggesting that manual handling generates airborne solvent. For example, kerosene (which is relatively volatile) had the highest airborne concentrations, whereas the hydrogenated terphenyls (whose volatility is low) produced unmeasurable concentrations. The data indicate that various paper types generated similar concentrations of dust during standardized paper handling in the laboratory.
The airborne formaldehyde concentrations were below the limit of detection (<0.05 mg/m3). This finding does not support formaldehyde as the cause of the health effects. The particle-bound solvents were also consistently below the detection limit (<0.0002 mg/m3), which corresponds to a dust solvent content of less than 1% by weight. Norback and Gothe [1983] concluded that no obvious climatic differences were evident between the two environments, even though health problems occurred in the offices and not in the printing shops. The author observed that these health problems occur in offices with both high and low levels of
| Solvent | |||||
|---|---|---|---|---|---|
| Paper type | Total dust | Kerosene | MIBP | Diarylethane | Hydrated terphenyl |
| Paper containing MIBP + kerosene | 0.05 | 0.81 | 0.06 | —[1] | — |
| Paper containing diarylethane | 0.02 | — | — | 0.03 | — |
| Paper containing hydrogenated terphenyl + kerosene | 0.05 | 0.70 | — | — | <0.01 |
| Ordinary paper | 0.05 | — | — | — | — |
| Control—without paper | 0.02 | — | — | — | — |
Source: Norbäck and Göthe [1983].
- ↑ Dash indicates that no measurement was performed.
