A monumental study - reconstruction of a 1920 granite shed.
Ayer-HE; Dement-JM; Busch-KA; Ashe-HB; Levadie-BT; Burgess-WA; DiBerardinis-L
Am Ind Hyg Assoc J 1973; 34(5):206-211
Working conditions of the 1920s were recreated using a small granite shed in Barre, Vermont operated for one week without any ventilation. Respirators were used to protect the granite cutters. The implications for the quartz threshold limit values (TLV) are discussed. Respirable mass samples were taken with 3 sizes of horizontal elutriatory samplers and 3 sizes of cyclone samplers. At various times breathing zone samples were taken. Respirable dust concentrations up to 49 milligrams/cubic meter (mg/cu M) and respirable free silica (60676860) concentrations up to 4.4mg/cu M were observed. Average respirable dust concentrations were 10 to 20mg/cu M of which 15 percent was free silica. Under the conditions studied, 10 million particles per cubic foot of granite dust appeared to be equivalent to about 0.2mg/cu M of respirable free silica. The authors recommend that respirable free silica concentrations be kept as far below present TLV as available control methods permit until the effects of inhalation on the health of workers can be further studied.
NIOSH-Author; Protective-equipment; Breathing-zone; Dust-collectors; Silica-dusts; Inhalation; Standards; Industrial-hygiene
American Industrial Hygiene Association Journal