Exposure to biogenic silica fibers and respiratory health in Hawaii sugarcane workers.
Sinks-T; Hartle-R; Boeniger-M; Mannino-D; Boyd-JE; Fernback-J; Hawkins-M; Grimes-G; Watkins-KL; Dill-P; Anderson-B
J Occup Med 1994 Dec; 36(12):1329-1334
The exposure levels of and effects from biogenic silica (7440213) (BSF) and asbestos on the respiratory health of workers from two plantations in the Hawaiian sugarcane industry were determined. Male sugarcane workers with nine or more years experience in harvesting related jobs were chosen, and divided into four BSF exposure categories: planting, harvesting, mill operations, and other workers. There were 355 participants in the study with an average age of 54 years. Health assessments were performed through a questionnaire and medical evaluation. BSF levels were evaluated from personal breathing zone air samples, and ranged from undetectable to 0.712 BSF per milliliter (BSF/ml). Of the four categories, only the harvest rake operator group was exposed to BSF concentrations greater than the 0.05 BSF/ml (mean BSF/ml 0.089). Ten samples contained asbestos at concentrations of 0.001 to 0.774 fibers per milliliter; the majority of asbestos exposed workers were machinists or mechanics. Shortness of breath was the most common respiratory symptom followed by wheezing and chronic cough. Sixty six workers had an obstructive pattern after pulmonary function testing, and 18 workers had a restrictive pattern. Obstruction was associated with cigarette smoking. A decrease in the forced expiratory volume per second to forced vital capacity ratio was associated with smoking and BSF exposure. Two workers had bilateral irregularly shaped opacities on their chest x-rays and neither were exposed to BSF. Based on a significant association between the prevalence of respiratory symptoms and cigarette smoking, the authors conclude that the occurrence of fibrotic lung disease in Hawaiian sugarcane workers did not result primarily from BSF or asbestos exposure.
NIOSH-Author; Humans; Occupational-exposure; Airborne-fibers; Agricultural-workers; Sugar-industry; Air-samples; Asbestos-fibers; Respiratory-system-disorders; Silica-dusts; Lung-irritants; Lung-disorders
Journal of Occupational Medicine