Industry-wide Study Research Articles

Worker exposure to perchloroethylene in the commercial dry cleaning industry.

The National Institute for Occupational Safety and Health (NIOSH) conducted industrial hygiene surveys at 44 commercial dry cleaning facilities in five states as part of an industry wide study to assess the health effects of long-term, low-level exposure to perchloroethylene (PCE). Time-weighted average (TWA) and peak exposures to PCE were determined by collecting personal air samples using activated charcoal tubes and battery-operated pumps. TWA exposures of the machine operators ranged from 4.0 to 149.0 ppm PCE. The geometric mean PCE exposure of the machine operators (22 ppm) differed significantly from the mean exposures of the pressers (3.3 ppm), seamstresses (3.0 ppm), and the concentrations in the front counter areas of the facilities (3.1 ppm). Te geometric mean 5-minute peak PCE exposure during textile transfer was 44 ppm while the mean 15-minute exposure was 33 ppm. No significant differences were found between exposures when either the TWA or the peak data were grouped by geographic location (i.e., state), or by the type of processing equipment used (i.e., "Combination" units vs. separate washing and drying units). Recommendations for work practices, ventilation, maintenance, plant layout and personal protective equipment are presented to reduce PCE exposures to lowest achievable levels.

Beryllium Sampling Methods

Three sampling methods for airborne beryllium are compared to validate observations made in a 1973 National Institute for Occupational Safety and Health (NIOSH) industrywide study of the beryllium industry which indicated that, in general, the three methods yielded different results for samples taken in the same environment. Under NIOSH contract a beryllium production facility was sampled in 1974 by the Atomic Energy Commission (AEC) personal total and personal respirable sampling methods over a period of one year. All samples were analyzed by atomic absorption spectroscopy. Statistical analysis of the resulting data by NIOSH confirms the observations made in the 1973 study that samples collected by the three methods produced different results. No reliable relationship was found to exist which would permit conversion of the result obtained by one method to a result obtained by either of the alternate methods. It appears that, in general, for large numbers of samples taken under the same sampling conditions, the values determined by the personal respirable sampling method will be lower than those obtained by the AEC method and the values determined by the personal total sampling method will be greater.

Summary of measurements of employee exposure to airborne dust and fiber in sixteen facilities producing man-made mineral fibers.

The results of an industry-wide study to determine the exposure of workers to man-made mineral fibers are summarized. The purpose of the study was to determine current employee exposures to airborne fibers and to utilize results to estimate past exposures. Measured exposures of workers to airborne total particulate matter and fibers are presented; samples were evaluated by phase contrast and electron microscopy. Results of the three year study, which encompassed 16 facilities and over 1500 eight hour samples, show that although there is a wide variation in concentrations of airborne fibers and particulate matter between and within the facilities surveyed, the concentrations of airborne particulate matter and fibers are generally less than 2.5 mg/m3 and 0.5 fibers/cm3, respectively. The norminal fiber size of the fibers manufactured and average airborne fiber concentration were highly correlated.

AN INDUSTRYWIDE STUDY OF PROGRAMED INSTRUCTION.

AN INDUSTRYWIDE STUDY OF PROGRAMED INSTRUCTION.