 in the ranks of American workers. Clause of the disease, dust. Results of the disease, disablement, poverty, death. Cure for the disease, none. Throughout America, workers exposed to dust grew fearful of their health, of their very lives. 1936, amid these alarming events, the Secretary of Labor called together a national conference to study this disease. A committee of 60 experts was appointed and a year later reported to the Secretary of Labor. Let's hear from Ms. Perkins herself. After a year of work, the National Silicon Conference Committee has just made its report of findings and recommendations. And I feel it to be my duty to make this report available to the working people of the United States and to their employers by every available method. This report shows how the silicosis occurs, where it occurs, and what the disease is. And it makes recommendations for its practical control. Above all, the report emphasizes that these control measures, if conscientiously adopted and applied, that silicosis can be prevented. This is the story of silicosis, a disease of the lungs caused by breathing fine particles of dust containing silica. Granite dust, its small particles consist mainly of free silica. The smaller the particles, the greater the danger to human lungs. Here is a fine mesh screen with over 100,000 openings to the square inch. Notice how readily the silica dust passes through. Yet this screen is so fine that it holds water. Every drop poured into the sieve is poured back into the glass. Here, dust particles taken from the air are being analyzed to determine workers' exposure. Granite dust, particles of which can enter a workman's lungs and cause trouble. This cross section shows the nose and throat passages through which dust is inhaled into the lungs. The fine dust particles enter the lungs and settle in the terminal air spaces. Physical and chemical changes occur. Scar tissue forms. Small at first, these scarred areas grow larger as time goes on. This tissue is fibrous, tough, and inelastic, and the lungs cannot adequately perform their task of carrying air to the blood. As a result, the affected worker becomes so short of breath he can no longer do his job. This magnified section shows the alveoli for small air spaces in the lungs. They supply life-giving oxygen to the blood. Silica dust clogs these spaces and deadly scar tissue forms. This is the way a silicotic lung appears to the x-ray. The black areas are dead tissue. Among many industrial operations where a silica hazard exists is the quarrying of granite, sandstone, flint, and other silica-bearing rock. This 35-ton block of stone has been hewn out of the quarry by pneumatic drills. These drills are dust producers. Those men are drilling in granite and the dust cloud arising contains large quantities of free silica. The trade calls these tools jackhammer, but workmen often call them widow-makers. These men are exposed to a serious silica hazard. Imagine breathing quantities of dust like this eight hours a day, day after day, year after year. After the stone is quarried, it is taken to the plant for surfacing and finishing. The granite surfacing machine produces quantities of dust. The worker must stand close to the machine in order to operate it. He is breathing dangerous dust. When crushed stone is passed over a vibrating screen, more silica dust is dispersed into the air. Workers nearby cannot escape this dust. Finely pulverized granite is put into bags to be used as asphalt filler or other uses. This machine is being operated in such a way that the workmen must breathe in clouds of harmful dust and this man is totally unprotected. Foundry shakeout, wherein castings are removed from the molds is also a dusty operation. These two men are working without any protection whatsoever. They are potential silicosis victims. Here is a typical American workman, one of the million who are dangerously exposed to silica dust. His name is John Steele. Once a master molder, he is still working in this foundry after years of exposure to silica. Once strong and healthy, John Steele is now weak and emaciated. He is short of breath. He cannot do even this work properly. It's him that he is sick, incompetent, can no longer do a day's work and that he must let him go. And John, his last time slipped. As a result of his disability, John, like thousands of others, is being fired. He is paid off, broken in health and in spirit, out of a job, he must seek work elsewhere. John Steele was more fortunate than many another silicosis victim. He was able to find work in a tombstone shed, work which was not too heavy and where he could earn a little money to help support his family. But he is still exposed to the enemy. Across John Steele's mind flashes his fate. How soon will he become a stark reality? How soon will he join the thousands of others who have succumbed to silica dust? These thousands shall not have died in vain if we use the knowledge we have gained to save others from the same fate. We know the practical engineering methods which will control the death-dealing dust. This worker has been employed at a dusty trade for several years. He is healthy, robust. He can put in a full day at hard work. Notice his deep chest and good general appearance despite years at his trade. He periodically goes to a skilled doctor in whom he has complete competence. The doctor gives him a thorough physical examination just as a check on his condition. His examination includes, among other things, the making of a routine x-ray film. Although a final diagnosis of silicosis cannot be made by x-ray alone, an accurate diagnosis is impossible without it. His healthy chest looks like this to the x-ray. There are no silica spots. He has been protected from dust. Notice the difference between the normal x-ray on the left and the silicotic lungs on the right. Sandblasting of rough castings in foundries is one of the dustiest of operations. These workers wear helmets like deep sea divers into which clean filtered air is fed. They work in a tightly closed room so that other workers in the foundry are not exposed. In many cases, silicosis control is just as simple as this. Oil sawdust sprinkled on floor. Or wet sweeping keeps the dust down. In other words, good plant housekeeping. The vibrating screen. See how dusty it is. Workers would be exposed where it not for the exhaust system which, when turned on, draws the dust off, carrying it through a system of pipes to a dust collector. This is the dusty bagging operation we saw earlier. However, with the exhaust system in operation, there is no dust in the air. The worker wears an approved filter respirator for added protection during periods of temporary exposure. The dust is being carried at high speed into the suction system where it is collected. And here is the way this dusty surfacing machine can be controlled by using a suction device. Note how the dust and stone chips are drawn into the hood and thus kept away from the workman's nose and mouth. In the granite quarrying industry, rock drilling is one of the dustiest operations. It can be made non-dusty and safe. One method is to force water through pipes to the point of operation. Water flows through this simple little device around the drill steel and prevents the dust from flying into the air. Here's another wet method used in the quarry. Water is fed through a hollow drill to the cutting edge of the tool. Notice the complete absence of dust. Had our John Steele's worked under these conditions, they would never have developed silicosis and could have continued to work at their trades in safety and comfort. We have seen but a few of the practical, simple and inexpensive control measures in actual use. However, they must be adopted more widely by employers, used more consistently by workers and required more generally by state and other agencies. Silicosis can be entirely prevented. The division of labor standards will give you full information. Stop silicosis.