Occupational diseases: a guide to their recognition, revised edition. Key MM, Henschel AF, Butler J, Ligs RN, Tabershaw IR, eds. Cincinnati, OH: National Institute for Occupational Safety and Health, 1977 Jun; :508-520
Physical hazards of exposure to oscillatory vibrations are discussed. Studies continue to determine the noise tolerance limits for protecting human hearing. Pain and injury or illness resulting from vibration conditions are also under study. Harmful effects of noise include hearing losses which may be temporary or permanent, startle reflexes, increased blood pressure, increased sweating, increased heart rate, changes in breathing pattern, and sharp contractions of the body muscles. Excessive noise can also result in the creation of a dangerous situation due to interference with communication. Use of ear protective devices is discussed. Occupational vibration exposure occurs in about 8 million workers in the United States, many in the transportation, farming, and construction industries. Others who are exposed include those who use chain saws, pneumatic tools, and vibratory electrical hand tools. Harmful effects include increased oxygen consumption and pulmonary ventilation, difficulty in maintaining steady posture, changes in bone structure involving spondylitis deformations, intervertebral osteochondrosis, and calcification of the intervertebral discs and Schmorl's nodes. Also, reports have been made of hypoglycemia, hypocholesteremia, low ascorbic-acid levels, gastrointestinal tract changes in gastric secretions and peristaltic motility, and changes in nerve conduction velocities.