Answer to Question #25794 in Physical Chemistry for UTSAV RAJ

Question

sample were collected in a zinc smelter to determine the exposure of a furnace tender to lead fume during his normal work duties which involves “furnace draws” and general activities around the furnace. Each draw lasts about 1.5 hr. These samples were collected at a flow rate of 3.5 LPM. The laboratory reported these lead masses on the samples for each draw: 1st draw: 12 ug: 2nd draw: 18 ug: 3rd draw: 25 ug. An 8 hour general room air sample collected at 1.9 LPM was found to contain 9.5 ug of lead. This worker spends 1.5 hours with each draw and the balance of his 8-hour day is spent watching the furnaces. Assume for the period of time he spends watching the furnaces, he has the same exposure as the general room air. You can be 95% confident that his true exposure for this day was between ug/m3 and ug/m3. At 95% confidence, would you conclude the exposure was in or out of compliance