Quartz and dust exposure in Swedish iron foundries.

Exposure to respirable quartz continues to be a major concern in the Swedish iron foundry industry. Recommendations for reducing the European occupational exposure limit (EU-OEL) to 0.05 mg/m3 and the corresponding ACGIH(R) threshold limit value (ACGIH-TLV) to 0.025 mg/m3 prompted this exposure survey. Occupational exposure to respirable dust and respirable quartz were determined in 11 Swedish iron foundries, representing different sizes of industrial operation and different manufacturing techniques. In total, 436 respirable dust and 435 respirable quartz exposure measurements associated with all job titles were carried out and are presented as time-weighted averages. Our sampling strategy enabled us to evaluate the use of respirators in certain jobs, thus determining actual exposure. In addition, measurements using real-time dust monitors were made for high exposure jobs. For respirable quartz, 23% of all the measurements exceeded the EU-OEL, and 56% exceeded the ACGIH-TLV. The overall geometric mean (GM) for the quartz levels was 0.028 mg/m3, ranging from 0.003 to 2.1 mg/m3. Fettler and furnace and ladle repair operatives were exposed to the highest levels of both respirable dust (GM = 0.69 and 1.2 mg/m3; range 0.076-31 and 0.25-9.3 mg/m3 and respirable quartz (GM = 0.041 and 0.052 mg/m3; range 0.004-2.1 and 0.0098-0.83 mg/m3. Fettlers often used respirators and their actual quartz exposure was lower (range 0.003-0.21 mg/m3, but in some cases it still exceeded the Swedish OEL (0.1 mg/m3. For furnace and ladle repair operatives, the actual quartz exposure did not exceed the OEL (range 0.003-0.08 mg/m3, but most respirators provided insufficient protection, i.e., factors less than 200. In summary, measurements in Swedish iron foundries revealed high exposures to respirable quartz, in particular for fettlers and furnace and ladle repair workers. The suggested EU-OEL and the ACGIH-TLV were exceeded in, respectively, 23% and 56% of all measurements regardless of the type of foundry. Further work on elimination techniques to reduce quartz concentrations, along with control of personal protection equipment, is essential.