Document RjwnKZ4jxeRBBNbD1KGaEJYyX

FILE NAME: Pennsylvania (PA) DATE: 1964 DOC#: PA029 DOCUMENT DESCRIPTION: PA Dept of Health Report - Hygienic Guide on Asbestos COMMONWEALTH OF PENNSYLVANIA DEPARTMENT OF HEALTH DIVISION OF OCCUPATIONAL HEALTH HYGIENIC INFORMATION GUIDE NO. 7 ASBESTOS P R O P E R T IE S: Asbestos la composed of a number of different m ineral which are silicates of variable composition, but basically are of a form of hydrous magnesium silicate . Their chief characteristic is a structure composed of long, p arallel, flexible fib ers, capable of repeated longitudinal subdivision. Many v a rie tie s are su fficien tly flexib le to be spun into yarn or woven on modified textile m achinery. Manufacturing processes can cause this m in e ra l to b reak up into many minute p a rtic le s . THRESHOLD LIM IT V A L U E (acceptable atm ospheric concentration for 8-hour work period): 5 m illion particles per cubic foot of a ir . M EDICAL ASPECTS: Long continued inhalation of asbestos dust may result in a form of pneumoconiosis known as asb estosis. The p rim ary effect of such inhalation is a condition of pulmonary fib ro sis. A characteristic finding of asbestosis is the presence of asbestos "bodies" in the lungs and sputum . Com plete roentgenologic study of the chest and histopathological findings are n e cessa ry to establish the presence of this d isease. The question of whether or not there is any relationship between the inhalation of asbestos dust and cancer of the lung is s t ill under d iscussion but m ore and m ore evidence is accum u lating that exposure to asbestos fibers m ay cause cancer of the lung. P R E V E N T IO N : a . Preplacem ent: Occupational history is a necessity. A complete physical exam ination, including a chest x -r a y , should be em phasized. b . Periodic Exam ination: A physical examination, together with a chest x - r a y film , should be given about once a y ear. C ases where pathologic lung changes have occurred should be relocated from employment in dusty operations. EXPOSURE CONTROL: a . A ll dust-producing operations should be equipped with lo ca l e x haust v entilation . Where p o ssib le , isolation or segregation of the operation should be observed, together with the use of wet m ethods. b. Housekeeping should be maintained with a view to preventing any accum ulation of deposited dust. Vacuum methods of cleaning are p re fe rre d , and should be perform ed "o ff-sh ift"*o r when le a st exposure to plant personnel would o ccu r. c . Where other methods of control are not feasible, dust respirators, of a type approved by the U . S . Bureau of M ines fo r protection against pneum oconiosis-producing d u sts, should be supplied to those em ployees subjected to the dusty atm osphere. d. A periodic determ ination of the dust le v els of the plant atm osphere should be made to a scertain the efficien cy of the control m easures in use. .. - 1IFW 6..H IH -19041 P R e v . 7/64 v ` ( ' i t :/ t