Females: FEVi (L)= —0.024 age (years)+0.033 height (cm)—1.729 Males: FEVi (L)=—0.029 age (years)+0.055 height (cm) —0.008 smoking (pack-years)—4.742
Airborne cotton dust was collected using vertical elutriators (General Metal Works, Inc) designed to collect particles less than 15 microns in aerodynamic diameter. Multiple area samples were collected from each of the six different work areas in yarn preparation operations of the two mills. Canadian neightbor pharmacy read The dust samples were collected throughout the work shift at both surveys—1981 and 1986. The work areas for all phases of yarn preparation included: opening, cleaning, carding, drawing, roving, combing, and spinning. There was no change in the methods of cotton processing during the 5-year period with the exception that mill 1 began to blend Dacron with cotton continuously for 2 years before the follow-up survey. At the first survey, 130 air samples were collected. At the second survey, 192 air samples were collected. Sampling procedures were in accordance with the US National Institute for Occupational Safety and Health (NIOSH) recommended guidelines, with the exception that the height of the elutriators was set at approximately 1.6 m to compensate for the slightly lower average height of the work force. Samples were collected in the same areas on follow-up as in the initial survey, and there was no change in the handling or method of weighing the filters.
Endotoxin analysis was performed on the dust filters using methods previously described. Briefly, filters were received in the laboratory sealed facedown in Parafilm M laboratory film (American Can Co, Greenwich, Conn). Sterile nonpyrogenic plasticware was used throughout these assays. Each filter was extracted separately in 10 ml of sterile, nonpyrogenic water (Travenol Laboratories, Inc, Deerfield 111) by rocking at room temperature for 60 mins. The extracts were decanted into plastic tubes and centrifuged for 10 min at 1,000 g. The resulting supernatant fluids were assayed in duplicate for the presence of Gram-negative bacterial endotoxins by means of the quantitative chromogenic modification of the Limulus amebocyte lysate test (QCL-100, Whitaker Biproducts, Walkersville Md). Since the distributions for dust and endotoxin were bimodal, both exposures were dichotomized into two groups A and В with cutoffs being 1 mg/m for vertical elutriator (VE) dust and 100 ng/m for elu-triator endotoxin.